“We need a second green revolution” Hybrid rice - Bayer ...

COURIER 

The Bayer CropScience Magazine for Modern Agriculture 2/08 

“We need a second green revolution” 

Hybrid rice – the next generation 

The cellular power station 

An end to the game of hide-and-seek 

How 

herbicides 

work

Contents 

2 “We need a second 

green revolution” 

6 Hybrid rice – 

the next generation 

10 Less stress – higher yield 

14 How herbicides work 

18 The cellular power station 

22 An end to the game of 

hide-and-seek 

26 Atento ®, a new solution 

for managing Asian rust 

28 Gaining the advantage 

through innovation 

Published by: Bayer CropScience AG, Monheim / Editor: 

Bernhard Grupp / With contributions from: Agroconcept 

GmbH, K. Doughty, M. Wiedenau / Design and Layout: 

Xpertise, Langenfeld / Lithography: LSD GmbH & Co. KG, 

Düsseldorf / Printed by: Dynevo GmbH, Leverkusen / Reproduction 

of contents is permissible providing Bayer is 

acknowledged and advised by specimen copy / Editor’s 

address: Bayer CropScience AG, Corporate Communications, 

Alfred-Nobel-Str. 50, 40789 Monheim am Rhein, 

Germany, FAX: 0049-2173-383454 / Website: 

www.bayercropscience.com 

Forward-Looking Statements 

This publication may contain forward-looking statements 

based on current assumptions and forecasts made by 

Bayer Group or subgroup management. Various known and 

unknown risks, uncertainties and other factors could lead 

to material differences between the actual future results, 

financial situation, development or performance of the 

company and the estimates given here. These factors 

include those discussed in Bayer’s public reports which are 

available on the Bayer website at www.bayer.com. The 

company assumes no liability whatsoever to update these 

forward-looking statements or to conform them to future 

events or developments. 

2 COURIER 2/08 

“We need a 

green 

Safeguarding food 

for a growing world 

population 

Modern agriculture: Combine 

harvester in a cereal field

second 

revolution” 

Arable land per capita 

2,000 sqm 

2,700 sqm 

5,100 sqm 

Our numbers are growing! By 2012, 

the world population is forecast to top 

the seven billion mark. In 2025, the 

number of people is even set to hit eight 

billion, with this rapid population 

growth taking place almost exclusively 

in developing countries, where over 80 

percent of all people already live. And it 

is precisely these countries that are 

already hit by food shortages. The World 

Bank estimates that the number of hungry 

people in the world could shoot up 

quite soon from 850 million at present 

to 950 million. United Nations forecasts, 

meanwhile, show that only 40 percent of 

the land that was available for growing 

food in 1950 will be available per capita 

for safeguarding the supply of food in 

2050. 

World population 

~ 9 Billion 

6.0 Billion 

2.8 Billion 

Source: FAO, Copyright Bayer CropScience 

2/08 COURIER 3

Securing food with less land 

Of the approximately 13 billion hectares of land covering the Earth’s surface, 

around 1.5 billion hectares are used for agriculture, with a further 3.5 billion 

hectares being used for meadowland and pasture. This area of land cannot be 

increased. Every year, around seven million hectares of agricultural land are 

lost as a result of building construction, erosion, desertification and other 

causes. Without modern crop protection measures and fertilization, we would 

already need significantly more arable land, namely around four billion hectares. 

As a result of population growth, agricultural production must increase by 

around two percent per year in order to be able to safeguard the amount of 

food required to supply all people. 

This figure does not yet take into account the increases in demand for meat. 

In China, for example, meat consumption has doubled in the last 15 years. For 

one kilogram of beef, it is necessary to produce well over seven kilograms of 

animal feed – this also drives up the demand for animal feed, which increases 

the competition for arable land for food production. 

On top of this, worldwide food reserves 

have now dropped to their lowest level for 

30 years. The main problem is that there is 

hardly any potential left for expanding the 

growing areas for wheat, rice or millet. In 

many parts of Asia, every last hill which 

can possibly be used has already been covered 

with fields and rice terraces. In many 

regions of Africa, it is likewise almost impossible 

to expand the amount of arable 

land. This is partly because the soils are 

simply not suitable, and partly because intensive 

farming would lead to desertification. 

Bayer CropScience research scientists assess enhanced stress tolerance characteristics in a new generation of 

hybrid rice. 


Extreme weather phenomena 

threaten harvests 

Another problem is that meteorologists 

worldwide are registering extreme weather 

events with increasing frequency – the absence 

or displacement of tropical rainfall 

as well as abnormal ocean current phenomena. 

One well known example is El 

Niño: every three to six years, torrential 

rains devastate whole tracts of land in 

South America, while at the same time extreme 

weather leads to droughts in South 

East Africa, Indonesia and Australia, and 

frost in Florida, causing enormous harvest 

losses for farmers. 

But it is not just natural catastrophes 

that cause billions of dollars’ worth of agricultural 

damage each year: persistently unfavorable 

farming conditions such as water 

shortages, increasing salination of arable 

soils and extreme heat and cold are prime 

causes of enormous harvest losses. Corn, 

rice and wheat are no longer able to withstand 

the extreme environmental effects. 

Climate change is adding to the stresses to 

which plants are subjected, with grave 

effects; even with the best of care for their 

fields, farmers regularly lose 30-70 percent 

of their harvests. 

Stop the self-destruction 

program in cereals 

“There is an urgent need for us not only to 

make agricultural production more efficient, 

but also to do it in a way which is 

sustainable,” says Professor Friedrich 

Berschauer, Chairman of the Board of 

Bayer CropScience. A key objective of the 

crop protection scientists is to increase 

corn, rice and wheat yields and make the 

plants more resistant to severe heat, cold, 

drought or intense sunlight. These factors 

put plants under enormous stress, triggering 

a process which can even lead to selfdestruction: 

the plant increases its energy 

consumption and can therefore no longer 

produce certain energy transport molecules, 

which are however needed by the 

cells to survive. The supply gap has dra- 

Fruit and vegetables supermarket in India. The wide range of

matic consequences for the plant, which 

can no longer supply leaves, fruit or stems 

properly with energy. Individual cells 

gradually die, followed ultimately by the 

whole plant. 

Stress-tolerant plants are 

considerably better at coping 

with climate fluctuations 

Researchers at Bayer Crop Science are using 

a trick to protect rice plants, for example, 

against a number of stress factors. 

They have put the plants on a fitness program. 

“Our idea was to get crops into 

shape,” says Michael Metzlaff of the Bayer 

CropScience Innovation Center for Plant 

Biotechnology in Ghent, Belgium. To 

achieve this, his team is pursuing two 

strategies: firstly, the scientists incorporate 

genes into the plants which should help 

them deal with excessive stress caused by 

dry and wet conditions. Secondly, they quite 

specifically deactivate individual genes 

which trigger excessive stress reactions in 

normal plants and lower the yield. “Our 

goal is to enable plants to produce high, 

stable yields over the longer term in spite 

of fluctuating environmental conditions,” 

Metzlaff says. 

fruits forms a good basis for a healthy nutrition. 

A “second green revolution” 

is needed 

For Berschauer, biotechnology is a vital 

tool to safeguard the supply of food for the 

world population in the future. “We need a 

second green revolution. If we use plant 

biotechnology in combination with crop 

protection solutions in a targeted manner, 

we can achieve significant advances in 

productivity,” comments Bayer Crop- 

Science’s CEO. Other experts share this 

view: according to the estimates of the 

Consultative Group on International Agricultural 

Research, only with biotechnology 

can harvests be increased by around 25 

percent. 

Antifungal agents help 

wheat plants to grow 

In Canada, Bayer CropScience researchers 

are already using advances in seed breeding 

to increase canola oil yields by up to 30 

percent compared with conventional varieties. 

In addition to plant biotechnology, 

new crop protection agents can also increase 

harvest yields. The latest example is 

the active ingredient trifloxystrobin. Farmers 

all over the world have been using this 

agent for years to protect cereal, vegetable 

and fruit crops against harmful fungal diseases. 

But trifloxystrobin, an antifungal 

agent belonging to the strobilurin group of 

active ingredients, can do more: it also 

increases the ability of plants to withstand 

stress. “Field trials show that crops in 

Stress causes dramatic harvest losses 

Yield (kg/hectare) 

20,000 

16,000 

12,000 

8,000 

4,000 

0 

which strobilurins are used produce better 

harvests than those protected with other 

types of antifungal agent,” says Dr. Dirk 

Ebbinghaus, a Bayer CropScience research 

scientist. Crops protected with trifloxystrobin 

also do much better than untreated 

plants under conditions of drought. “Our 

active ingredient clearly triggers a number 

of different positive effects in the plant 

which result in an above-average increase 

in yield,” says Ebbinghaus. The latest research 

results have also shown that certain 

active ingredients, i.e. the Bayer Crop- 

Science insecticide Gaucho ®, can even 

make rice plants more resistant to fluctuations 

in the salt content of water. 

Protecting biodiversity 

Because the demand for high-quality food 

in adequate quantities and at affordable 

prices must not be allowed to jeopardize 

nature, Bayer Crop Science has committed 

itself to an important principle: using stateof-the-art 

technologies, the company wants 

to help both small and large-scale farmers 

achieve higher productivity on land already 

used for agriculture. This protects natural 

habitats from being converted into arable 

land. ■ 

Utz Klages 

Find more information at 

www.bayercropscience.com 

Corn Wheat Soy Millet Oats Barley 

Losses caused by 

abiotic factors 

(drought, heat,…) 

Losses caused by 

biotic factors 

(insects, fungi,…) 

Average yield 

Source: Bayer CropScience 

Stress reduces harvests dramatically: cereals appear to suffer particularly from 

abiotic stress caused by heat, cold, drought or the oxygen deficiency that results 

from stagnant water or compacted soil. The potential harvest (total column length) 

is partly compromised by insect pests, plant diseases and competition from weeds. 

However, abiotic factors are responsible for the lion’s share of harvest losses. 

2/08 COURIER 5

Hybrid rice 

– the next generation 

Bayer CropScience’s hybrid rice is known for its especially 

high yield potential. A new variety from the Arize product 

range also has an important, additional characteristic: 

Arize Dhani is resistant to bacterial leaf blight. 

In 2008, Indian rice farmers were able to 

benefit for the first time from a new option 

for protecting their crops against attack 

by the bacterial pathogen Xanthomonas 

oryzae. Arize ® Dhani is the name of the 

new variety that Bayer CropScience 

has just brought onto the market in five 

Indian States. This is the world’s first 

hybrid rice with greater than 95 percent 


resistance against all known races of 

bacterial leaf blight. 

Bacterial leaf blight is a particular problem 

in the eastern Indian states, especially 

Chhattisgarh, West Bengal and Orissa. “A 

total area of about six to seven million 

hectares is affected here”, explains Arun 

Mittal, rice-product manager of Bioscience 

in India. BioScience is the Bayer Crop- 

Science Business Unit that specializes in 

the development and production of varietal 

seed. 

The rice-growing area affected by bacterial 

leaf blight corresponds to about 15 

percent of the total Indian crop. Depending 

on the severity and timing of infection, 

harvest losses of between 20 and 60 percent 

can occur, according to Mittal. In fact,

actericidal agents are available for use 

against bacterial leaf blight – but none of 

them has proven effective enough to date. 

In developing Arize Dhani, Bayer Crop- 

Science has taken advantage of the fact 

that nature already presents us with rice 

varieties that are partially resistant to bacterial 

leaf blight. Breeders tested the resistance 

properties of such varieties against 

various isolates of Xanthomonas oryzae that 

had been collected for the purpose from locations 

throughout India. Their investigations 

showed that none of these varieties 

possessed resistance that was effective 

against the entire spectrum of bacterial leaf 

blight isolates occurring in India. 

In order to create a variety that achieved 

just this, the breeders brought the resist- 

A technician at the Bioscience site in Ghent, Belgium, 

removes seeds from a rice plant. 

ance genes from the naturally-occurring 

varieties together into the optimal combination. 

They did this through advanced 

breeding, using molecular markers. The 

comprehensive resistance thus achieved 

was then brought together with a strong 

yield potential using well-proven hybridization 

technology. Like Bayer CropScience’s 

other hybrid rice varieties, Arize Dhani has 

a yield potential that is 20 to 30 percent 

higher than that of conventional rice varieties. 

Its yield advantage over conventional 

varieties is even greater under conditions 

of infection by bacterial leaf blight. “When 

the disease hits, farmers who use Arize 

Dhani can produce up to 80 percent more 

yield than their neighbours using classical 

varieties”, says Arun Mittal. Arize Dhani 

will therefore help farmers operating in areas 

threatened by the disease to achieve 

greater income security. It’s no coincidence 

that the product is called “Dhani”: this 

Hindi word is used to describe a “rich person”. 

Market leader in hybrid rice 

Arize Dhani is already the eighth hybrid 

rice variety that Bayer CropScience has introduced 

in India. All of these products are 

characterized by an especially high yield 

potential. The availability of such a large 

2/08 COURIER 7

number of different products can be explained 

in terms of differences in the properties 

they possess, such as the rice’s grain 

shape and size, and aroma; it also has to do 

with adaptability to local climatic conditions. 

Arize Dhani is the first hybrid rice that 

offers the additional benefit of broad resistance 

to bacterial leaf blight. As a global 

leader, Bayer CropScience plans to continue 

to bring further second-generation 

hybrid rice varieties of this type onto the 

market. These varieties deliver a double 

benefit: high yield potential combined 

with, for example, resistance to a particular 

pest or to other types of stress. 

Bayer CropScience is market leader in 

the hybrid rice market in India. However, 

hybrid rice currently accounts for only two 

percent of the Indian rice cultivated area. 


Increasing this proportion would be a way 

of increasing the productivity of Indian 

rice cultivation, which is clearly lower than 

in other countries “India is only in 16th 

place in terms of rice productivity”, says 

Frédéric Arboucalot, Global Manager of 

Bayer CropScience’s rice seed business. 

The comparison with the People’s Republic 

of China – the other country confronted 

with the need to feed a population of more 

than a billion – is telling. With 44 Million 

hectares, India’s area under cultivation is 

one and a half times bigger than that of 

China; nevertheless, Chinese farmers harvest 

considerably more rice. In 2006, the 

figure was 184.1 million tonnes for China, 

compared with only 136.5 million tonnes 

for India. Productivity in China equated to 

more than six tonnes of rice a hectare, 

compared with just over three tonnes a 

What is hybrid rice? 

Hybrids are produced by crossing two 

different parental plant lines. Under this 

approach, one of the lines is deliberately 

sterilized to prevent the usual process of 

self-pollination. The plants, which are then 

purely female, receive pollen exclusively 

from plants of the second parental line 

growing in the immediate vicinity. In this 

way, the genetic material of the two lines 

is combined, and the female plants produce 

the hybrid seed. 

Targeted choice of the two parental 

lines allows to produce hybrids with 

specific, desirable properties: for example, 

a particularly high yield potential. In fact, 

finding suitable parental lines is an 

expensive and protracted process. Bayer 

CropScience develops the lines it needs in 

India, Brazil, USA and soon in Thailand. 

Thanks to the modern molecular 

biology techniques used at its Rice 

Research Laboratory in Singapore, Bayer 

CropScience is now able to accelerate the 

development of new hybrid varieties. The 

company is a world leader in hybrid technology; 

besides rice, Bayer CropScience 

also develops oilseed rape and cotton 

seed using the hybrid approach. 

hectare in India. Hybrid rice was introduced 

into China as early as the 1970s, and 

it is now grown on more than half of the 

area under rice cultivation. 

Increasing demand for rice 

In an article for Rice Today – the house 

magazine of the International Rice Research 

Institute (IRRI) in the Philippines – at the 

beginning of 2008, the IRRI researcher Dr. 

Sushil Pandey predicted that the demand 

for rice will continue to rise in coming 

years. In fact, an additional 50 million 

tonnes will be needed by 2015; Asia alone 

will account for 38 million tonnes of this. 

For comparison: the total global rice harvest 

in 2006 was around 635 million tones, 

according to FAO-figures. 

The main reason for the anticipated increase 

in demand is strong population 

growth. In India, the population has been 

increasing by 1.7 percent a year on average. 

The UN forecasts that it could climb 

from 1.10 billion (2005) to 1.26 billion by 

2015. A further increase is also expected in 

China – despite the “one child policy” – to 

1.39 billion people by 2015. According to 

the demographers’ forecasts, the whole of 

Asia could have a population of 4.35 billion 

inhabitants by then; in 2005, the figure 

lay at 3.91 billion. In other words, an 

eleven percent increase in ten years. 

The major part of the required increase 

in production must come from an improvement 

in the yield per hectare, points out Dr. 

Pandey in his Rice Today article, because 

there is no capacity for extending the area 

under cultivation. In China, the rice-growing 

area actually declined by three million 

hectares between 1997 and 2006. The reason: 

rice farming is increasingly in competition 

with other forms of land use. 

This increase in productivity will be 

achievable primarily through the development 

and distribution of improved technologies, 

according to Dr. Pandey. This is, 

at the same time, the only possibility of 

avoiding a further, rapid increase in the 

price of rice. 

New Rice Research Laboratory 

in Singapore 

Among these technical solutions will be 

new possibilities for crop protection, as 

well as seed with improved yield potential. 

In order to bring forward this type of development, 

Bayer CropScience is investing 

five million Euros in its new Rice Research 

Laboratory in Singapore. The Institute 

began its work in June 2008, and it

will contribute a significant extension in 

breeding capacity for hybrid rice, among 

other things. Here, the use of modern biochemical 

methodology will accelerate the 

otherwise prolonged process of developing 

new varieties. 

One example is DNA marker technology, 

through which certain genes can be detected 

in the genetic material – thus allowing 

scientists to determine to what extent 

the genes have been retained during crossing 

and appear in the progeny. Indeed, Bayer 

CropScience’s researchers used DNA 

marker technology to follow the fate of individual 

resistance genes during the crossing 

process that led to the development of 

the bacterial leaf blight-resistant Arize 

Dhani. DNA marker analysis is an integral 

tool in molecular breeding, which in turn 

helps to accelerate the development of new 

varieties significantly. 

Bayer CropScience had good reason to 

choose Singapore as the location for its research 

laboratory. “This is the best place 

for the Institute, because 90 percent of 

global rice cultivation takes place in Asia”, 

explained Dr. Joachim Schneider, who 

leads Bayer CropScience’s BioScience 

Business Unit, at the laboratory’s inauguration 

ceremony in June. “With this laboratory, 

we want to be able to develop new, 

highly-efficient rice hybrids more rapidly, 

so that rice farmers throughout Asia can 

then benefit from them”, declared Dr. 

Schneider. 

Bayer CropScience’s hybrid rice is now 

on the market in six Asian countries. Besides 

India, these are Bangladesh, Indonesia, 

Pakistan, the Philippines and Vietnam. 

Arize-Products are also available in Brazil, 

and further market introductions are 

planned in several other countries, including 

Thailand and the USA. 

The product portfolio will also continue 

to expand. Just as Arize Dhani combines 

high yield potential with resistance to bacterial 

leaf blight, other products will bring 

different supplementary characteristics. 

“Examples of the characteristics we are 

currently working into hybrid rice varieties 

include resistance to Brown Plant Hopper, 

and significantly-increased tolerance to 

salinity or submergence”, explains Bio- 

Science’s Frédéric Arboucalot. In the 

meanwhile, plans for Arize Dhani in 2009 

include further expansion into the Indian 

market, and introduction in Bangladesh. ■ 

Karl Hübner 

Bacterial leaf blight (Xanthomonas oryzae) lesions on the leaves and ear of rice plants. 

Bacterial leaf blight 

The most characteristic symptoms of bacterial leaf blight are light-coloured, 

longitudinal stripes on the leaf lamina. Badly-infected plants first wilt, then quickly 

dry out. Diagnosis of the disease can be confirmed by cutting off the leaf at the 

lower end of a lesion and dipping the cut end into water: masses of bacteria can 

be seen against the light, streaming into the water, which eventually becomes 

cloudy. 

Warm temperatures and high humidity favour the development of bacterial 

leaf blight. Damp areas, strong winds that damage the rice plants, and over-fertilising 

are further factors that encourage the disease. Moreover, the presence of 

weeds or infected rice stubble ensures the survival of the pathogen between 

crops, such that a new outbreak of the disease can occur as soon as the following 

crop is sown. 

The younger the plants are at the time of infection, the greater the resulting 

harvest loss. In some regions, local losses of up to 60 percent are recorded. Asian 

countries are particularly badly affected: besides threatening millions of hectares 

in India, the disease is also a problem in other Asian countries such as 

Bangladesh, Myanmar, Japan and Indonesia. 

Touring the new Bayer CropScience Rice Breeding Support Laboratory are Dr. Joachim Schneider, Head of 

BioScience (far left), Mr. Julian Ho of the Singapore Economic Development Board (second from right), and 

Mr. Marcus Yim of Bayer South East Asia (far right). 

2/08 COURIER 9

Less stress – hig 

Trifloxystrobin: a well-proven fungicide 

with additional benefits 

Heat makes the farmer sweat: but crop plants also become stressed 

under conditions of high temperature and water shortage – with yield 

losses as the result. Scientific studies have demonstrated that Bayer 

CropScience fungicides containing the active substance trifloxystrobin 

can improve the stress tolerance of plants, thereby securing the harvest.

her yield 

Whether in fruit orchards in Baden, 

French vineyards, Brazilian soybean fields 

or the extensive areas of maize and wheat 

grown in the American Mid-West – farmers 

around the globe are using Flint ®, Nativo ® 

and Stratego ® to protect their crops against 

damaging fungal diseases. Flint, the wellproven 

product from Bayer CropScience, 

has built up a reputation over the years as a 

specialist against scab. Vintners also 

appreciate this user-friendly fungicide because 

of its excellent activity against powdery 

mildew and phomopsis, as well as for 

the fact that it does not endanger beneficial 

insects. In South American countries, Nativo 

is used to control a range of diseases in 

soybean, rice and vegetables; farmers in 

North America put their trust in the Stratego 

brand when it comes to protecting 

against cereal diseases. 

These brands, along with several others 

Bayer CropScience offers farmers in more 

than 90 countries, have one thing in common 

– they contain the active substance trifloxystrobin. 

This compound belongs to 

the chemical class of the strobilurins, and 

it obviously possesses characteristics that 

set it apart from other fungicides. Besides 

High temperatures and drought cause stress 

to crop plants, resulting in harvest losses. 

its efficacy against fungal diseases, it also 

appears to have a positive influence on 

plant growth and yield. Many farmers who 

treat their crops regularly with Flint, Stratego 

or Nativo have observed that the plants 

grow more robustly, and that their leaves 

are a more intense green. But there’s more 

to it than that: “Field trials confirm that the 

yield of many different crops increases 

much more when strobilurins are applied 

than when fungicides from other classes 

of active substance are applied.”, explains 

Dr. Dirk Ebbinghaus, Crop Protection 

Research Scientist at Bayer CropScience. 

Researchers around the world are seeking 

an explanation for this so-called greeningeffect. 

Dr. Ebbinghaus’ research group at 

Bayer CropScience is taking a close look at 

trifloxystrobin in order to investigate its 

full potential. The aim is to be able to show 

how the line of products from Flint to Nativo 

can be used in a more directed way to 

achieve the yield increases of which they 

are known to be capable. 

Biotic and abiotic stress 

“Strobilurins appear to trigger a whole 

range of positive effects in the plant, which 

then combine to produce higher-than-average 

yields”, explains the researcher. One of 

the most important factors: trifloxystrobin 

seems to increase the plant’s ability to tolerate 

stress. Ebbinghaus’ team has found 

that crop plants treated with the Bayer 

product are better able to tolerate water 

shortage than untreated plants. “Against a 

background of impending climate change, 

this result is particularly interesting”, emphasizes 

the researcher. Farmers are already 

more worried today about prolonged 

periods of drought than about problems 

caused by pests, diseases and weeds. A 

large number of effective crop protection 

agents are available to control these socalled 

biotic stress-factors. In contrast, 

farmers are more-or-less helpless to compensate 

either for water shortage and the 

burning sun, or for the converse - unexpected 

cold periods or excessive rainfall. 

Ebbinghaus makes it clear how important 

this is: “Yield losses due to stress caused by 

climatic factors can be enormous. Experts 

estimate that up to 80 percent of harvest 

losses around the world are attributable to 

2/08 COURIER 11

Marketing expert Dr. Albert Witzenberger (right) und researcher Dr. Dirk Ebbinghaus are very satisfied with the 

results of studies. Trifloxystrobin-treated plants are looking good – and the measurements underline this. 

abiotic stress factors such as drought, heat, 

cold or flooding”. Agricultural scientists 

expect that the anticipated climate changes 

will make the situation even worse. The 

worrying implications: considerable economic 

penalties for farmers in some of the 

world’s regions, and a world-wide shortage 

of basic foodstuffs. 

If this situation is to be kept under control, 

crop protection agents that strengthen 

crop plants’ resistance to stress are among 

the tools that are needed. The trifloxystrobin-containing 

Bayer fungicides Flint, 

Stratego and Nativo have the potential to 

do this. The work of the scientists in 

Ebbinghaus’ group has provided an insight 

as to why plants treated with trifloxystrobin 

are better able than untreated plants 

to withstand periods of drought. “Drought 


means stress for every crop plant, and they 

respond by releasing free radicals”, explains 

Ebbinghaus. These are actually poisonous 

to the plant, but they can nevertheless 

render them harmless through the activity 

of certain enzymes. “Our results indicate 

that trifloxystrobin increases the activity 

of these enzymes”, he adds. 

When it comes to lack of water, many 

crop plants switch to a sort of emergency 

programme. An example: lemon trees will 

respond to a period of drought during the 

fruit development period by dropping most 

of their fruit prematurely (in nature, the 

few remaining lemons would then ensure 

the continuation of the species). “Trifloxystrobin 

obviously has the potential to influence 

the plant’s water balance positively, 

such that this type of emergency response 

Investigating the distribution of the active 

substance on cereal leaves. 

is delayed”, suggests Dr. Albert Witzenberger, 

Fungicide Product Manager at Bayer 

CropScience. This is another of the substance’s 

assets. Witzenberger himself saw 

how dramatic this effect can be in the summer 

of 2005, whilst visiting a citrus plantation 

in south-east Brazil. He describes 

the bleak situation: “It hadn’t rained in the 

region for weeks. Most of the trees had already 

shed the portion of their lemons that 

were still unripe”. But some of the lemon 

trees appeared to be resisting the heat and 

lack of water – they were still replete with 

fruit. “The reason was obvious: these were 

the trees that had been treated with our 

fungicide”, he explains. 

But that isn’t the end of the yield- and 

quality-increasing properties that make the 

Bayer active substance so interesting for 

farmers. It is obviously also capable of ensuring 

that the harvested commodity contains 

more of its most valuable constituents. 

Trifloxystrobin sets itself further 

apart from other substances in the same 

class through its effect on protein synthesis 

in cereals, as studies in the United Kingdom 

have shown: wheat plants that have 

been treated with trifloxystrobin are able to 

use the nitrogen that is available in the soil 

more effectively. 

And it’s not only the protein content of 

wheat grain that is increased: it also contains 

more starch. Ebbinghaus explains the 

reasons for both of these effects: “The stro-

If trees suffer stress – for example 

during a drought – they drop the 

majority of their fruit. The small 

remaining crop then ripens, but is 

nevertheless unable to compensate 

in terms of harvest. 

bilurins stimulate not only photosynthetic 

activity, and thus the production of starch, 

they also increase nitrogen assimilation – 

one of the basic foundations of protein 

synthesis”. 

The ability of strobilurins to improve 

yield also manifests itself in maize crops. 

The more than 600 field trials with Stratego 

that Bayer CropScience has conducted 

in North America demonstrate this conclusively. 

Product Manager Witzenberger 

summarizes the results as follows: “Trifloxystrobin-treated 

maize plants are generally 

greener and more stable. The corns 

in the cobs are larger, and have better quality, 

because they contain more sugar and 

starch.” This leads to measurably higher 

yields: the average corn yield increase in 

response to treatment was greater than 680 

liters per hectare. This has impressed many 

North American farmers. For example 

Tim Geiger, who cultivates maize on large 

holdings in Ottawa and Illinois: “It was unbelievable. 

My fields contained plants that 

had developed in a much healthier way. 

And the yields were higher than they’ve 

ever been.” ■ 

Iris Freundorfer 

Strong retention – long duration of action 

Trifloxystrobin’s main job is to protect the plant from fungal infection. 

The active substance succeeds in doing this because it inhibits respiration 

in fungal cells, thus removing the pathogen’s ability to use energy. While 

other fungicides are also able to do this, trifloxystrobin stands out because 

of its so-called “mesostemic activity”: this term describes the active substance’s 

unique behavior during uptake and distribution on, and within, 

the plant. 

Put in concrete terms, this means that trifloxystrobin sticks particularly 

well to the leaf surface, building a depot of active substance molecules 

which even heavy rain fails to wash off to any extent. The depot provides 

for a steady redistribution of the active substance across the leaf, and 

small quantities also penetrate gradually into the leaf tissue. The result 

is a particularly long duration of action. 

At the same time, mesostemic behavior is a prerequisite for trifloxystrobin’s 

anti-stress bonus; the unfolding of this useful side-effect also 

depends on the steady release of the right “dose” of active substance 

into the plant. 

2/08 COURIER 13

How 

herbicides 

work 

The effects of crop protection agents are tested in the greenhouse. 

Without the means to control weeds, 

neither the required yield nor the desired 

quality of the products deriving from a 

crop can be guaranteed. Under most 

circumstances, herbicides are the cheapest 

and most reliable form of weed control. 

However, they should be used only after 

other, cultural options for weed control 

have been considered and put into practice. 

In order to avoid the problems that arise 

if an active substance is over-used, it is 

necessary to select a rotation in which herbicides 

with different modes of action can 

be applied. Knowledge of the mode of action 

of herbicides can help towards developing 

a successful strategy for controlling 

weeds. 

How are herbicides 

taken up by the plant? 

In order to be effective, herbicides must be 

able to move from the spray deposit (foliar 

herbicides) or the soil solution (soil herbi- 


cides) into the plant. Products are classified 

as contact or systemically-active herbicides, 

depending on the extent and nature 

of uptake, redistribution and activity 

within the plant. 

1. Foliar herbicides 

The contact herbicides belong to this 

group. They penetrate into the plant exclusively 

or predominantly via the leaf, and 

are then redistributed only to a limited extent. 

They therefore cause damage to the 

weed plant at, or near, the point of penetration. 

This means that contact herbicides tend 

to be effective mainly against species that 

lack stored reserves, such as annual weeds. 

The uptake of systemic foliar herbicides 

occurs mainly via the leaf, and is followed 

by extensive redistribution within the 

plant. The best-known examples are the 

growth substances, which interfere with 

the balance of growth hormones in the 

plant. Most grass herbicides and bindweed 

products also work via the leaf. 

Foliar herbicides are redistributed in the 

plant mainly via the transpiration stream 

that flows through the plant’s vascular bundles. 

The assimilates produced by photosynthesis 

in a particular leaf are only exported 

if it is producing more than it needs 

for growth and respiration within its own 

tissues. The greatest export of assimilates 

occurs in fully developed, photosynthetically-active 

leaves when weather conditions 

are optimal. Young, still-developing 

leaves do not export sugars – and herbicides 

applied to them are not re-distributed 

to any extent. Temperature is important for 

herbicide efficacy: at temperatures below 

10°C, activity is usually low; whereas at 

temperatures greater than 25°C, there may 

be scorching of the crop plant, or reduced 

activity against the target species.

Special additives protect crop plants against the effects of herbicides. These are called „safeners“. Bayer CropScience is recognized as one of the world leaders in this technology. 

2. Soil herbicides 

The uptake of these active substances occurs 

via the roots, and is followed by re-distribution 

within the plant. The herbicides 

tend to be active in the leaves, or other 

above-ground parts of the plant, where 

they disrupt respiration processes and photosynthesis. 

The active substances reach 

the soil through the medium of water, and 

can remain there for some time. Soil herbicides 

should therefore only be applied to 

moist soils: under dry conditions, these 

products may lose their activity altogether. 

Soil herbicides play an important role in 

the control of weed grasses and dicotyledons 

during the pre-seeding and pre-emergence 

periods, or sometimes in the early 

post-emergence period. Examples include 

active substances such as metazachlor in 

oilseed rape and flufenacet (in Cadou ®) in 

cereals. 

3. Foliar and soil herbicides 

Some herbicides are active via both the 

leaf and the soil. Examples include the 

ALS-inhibitors, e.g. Atlantis ® and Husar ®. 

The relative degree of uptake via leaves 

and roots of products within this category 

of herbicides determines the timing of application 

– whether pre-emergence, early 

post-emergence or from the 3-leaf stage 

onwards. Combined foliar and root uptake 

can be achieved using a mixture of active 

substances: a typical example of this type 

of mixture is the sugar beet herbicide Betanal 

® Expert. 

4. Safeners 

Safeners are herbicide additives that accelerate 

the breakdown of the active substance 

within the crop plant. In contrast, 

they do not interfere with the intended action 

within target grass weeds, which apparently 

possess different variants of the 

relevant target enzymes. The product Atlantis, 

for example, has excellent activity 

against grasses. It would not be possible to 

use Atlantis in cereals – which, strictly 

speaking, are also grasses – if the product 

didn’t contain a safener. The safener activates 

an enzyme in cereals that accelerates 

the breakdown of the active substance, thus 

making the cereal plant insensitive to it. 

The secret is that the safener does not activate 

the corresponding enzyme in weed 

grasses – they remain sensitive and are 

killed off. 

Mode of action 

The mode of action describes the way in 

which physiological processes within the 

plant are influenced by the herbicide. In 

most cases, the active substance binds to a 

protein, thereby blocking one of the plant’s 

essential metabolic processes. The protein 

is usually an enzyme that regulates a particular 

biochemical reaction within the 

metabolic chain. However, the inhibition 

can also take place at structural and regu- 

2/08 COURIER 15

latory binding sites. Herbicides tend to 

possess a single main mode of action, but 

many also have secondary sites of action at 

which they can also disturb the plant’s metabolism. 

Herbicides are classified into different 

groups according to their main site of action 

within the plant’s metabolism. Here is 

a list of the various modes of action: 

• Photosynthesis inhibitors 

• Pigment synthesis inhibitors 

• Amino acid synthesis inhibitors 

• Fatty acid synthesis inhibitors 

• Cell division inhibitors 

Photosynthesis is among the plant’s 

most central metabolic processes, and is 

thus a particularly suitable target for herbicidal 

action. Photosynthesis inhibitors can 

disrupt the electron transport system of 

Photosystem II, or they can inhibit the formation 

of radicals in Photosystem I. Both 

have fatal consequences for the target 

weed, the cells of which are no longer able 

to store the energy derived from light. 

Herbicides can also disrupt photosynthesis 

indirectly, by inhibiting the synthesis 

of compounds that are important to it – 

pigments such as carotenoids, chlorophylls 

and cytochromes. The carotenoids, for example, 

have a protective function within 

photosynthesis, and it is this very function 

Modes of action of herbicides 

Inhibition of amino acid synthesis 

Product examples: 

Alister, Atlantis, Attribut, Basta, Husar, Maister 

Raw materials 

Site of action of the herbicide 

ALS 

(enzyme) Amino acid = 

building-block 

for proteins 

······· ······· 


Amino acid chain = protein 

that is shut off by herbicides. Products possessing 

this property include soil and foliar 

herbicides that can be used at an early development 

stage in autumn or spring 

against both mono- and dicotyledons (e.g. 

Mikado ®). 

Among the most well-known herbicides 

are those that inhibit the synthesis of 

amino acids and thus disrupt the production 

of proteins, including enzymes. Here, 

three important target enzymes can be affected: 

glutamine synthetases (target of 

glufosinate in Basta ®), 5-EPSPS-Synthase 

(target of glyphosate) and acetolactatesynthase 

(target of ALS-inhibitors). The 

latter enzyme is the target of action for sulfonylureas 

and the imidazolinones. With 

Husar, Atlantis und Maister ®, the Bayer 

CropScience portfolio has some wellproven 

herbicides from this class. 

Fatty acid metabolism is important to 

the process of cell membrane formation. 

Disturbance of this process through the action 

of a herbicide leads to the development 

of a thinner cuticle, and thus to a disruption 

of water uptake: this type of action 

is characteristic of FOPs (e.g. Puma ® 

Super) and DIMs. But compounds from 

other groups can attack fatty acid metabolism 

too: another example is ethofumesate 

(Betanal ® Expert). 

Other herbicides act like plant hormones 

(auxin herbicides) and set off uncontrolled 

cell growth. This is why the 

term growth substances is also applied to 

representatives of this group. Examples include 

the phenoxyacetic acids such as the 

well-known MCPA-, MCPP-P- and 2,4-D 

compounds. 

The process of cell division is vitally 

important. Some herbicides inhibit the system 

that regulates cell division – the 

microtubule system – such that cells can 

develop with several nuclei or too many 

chloroplasts. The grass herbicide flufenacet 

belongs to the group of substances 

that prevent cell division in plant tissues. 

Decision criteria 

Inhibition of fatty acid synthesis 


Betanal Expert, Puma Super 

Raw materials 

ACCase 

Cell membrane 

Herbicides should be applied according to 

the principles of Good Agricultural Practice 

and Integrated Crop Protection. This 

means that local conditions, rotation, and 

possible cultural methods should all be 

considered when developing a strategy for 

controlling weeds. Rotation is particularly 

important, and it has a direct influence on 

soil cultivation, the incidence of weeds and 

the ability of a crop to compete with them, 

and it determines the spectrum of herbicides 

that is available for weed control. 

Oils and 

fats 

Inhibition of cell di 


Cadou, Husky 

Without herbicides 

Normal cell division

vision 

If herbicide use becomes necessary, the 

first step towards choosing the most suitable 

product is to determine which weed 

species are present – or are likely to appear 

– and the current and anticipated density of 

infestation. The prevalent weed flora and 

the known thresholds of action determine 

the choice of the best herbicide, based on 

its spectrum of activity. 

The efficacy of a product and the overall 

success of weed control are influenced 

by a number of factors, including the 

growth conditions, the timing and rate of 

application, the technology used to apply, 

and other, local circumstances. If all of 

these factors are considered together, then 

the product’s full potential can be realised. 

But economic factors also play a role in the 

decision-making process. Depending on 

the situation on the farm and the number 

and types of different crops grown, early 

treatment of cereals can help to avoid work 

peaks later in the season. The decision as 

to whether to treat pre-sowing, or pre- or 

post-emergence, influences both the 

choice of herbicide, and the work-regime 

throughout the season. 

Herbicide-treated 

No cell division 

Resistance 

Inhibition of photosynthesis 


Betanal Expert, Betanal Quattro, Sencor 

Light energy 

Limiting the rotation to one or two crops, 

and intensive use of herbicides with identical 

or similar modes of action, favour the 

development of resistance in weeds. Shifts 

within the weed population always start 

with single, resistant individual plants – 

these are universally present in nature. The 

repeated use of herbicides with a common 

mode of action creates a selection pressure 

that promotes the spread within the population 

of plants possessing the resistance 

characteristics. Unless the control strategy 

is changed, these resistant weeds can 

Site of action of the herbicide 

Solar energy 

conversion 

enzymes 

Chloroplasts 

(in plant cells) 

Sugar + 

oxygen 

spread such that they eventually gain the 

upper hand, and can no longer be controlled 

effectively. 

Thus to be on the safe side, resistance 

management should be considered in advance, 

whilst planning which crop to grow. 

The key to active substance rotation is to 

design the rotation so that the same mode 

of action is not used twice in successive 

crops. ■ 

Inhibition of pigment synthesis 


Alister, Husky, Laudis, Mikado 

Without herbicides 

Carotenoids protect the 

green pigmentation 

Ultra-violet light (damaging) 

Visible light (productive) 

Herbicide-treated 

UV-light destroys green 

pigmentation 

2/08 COURIER 17

The cellular powe 

Plant cells can capture light energy and store it ready 

for use in metabolism, so they’re just like miniature 

solar panels – only considerably more efficient. 

18 COURIER 2/08

station 

Macrocosmos, microcosmos – it’s always 

fascinating to see that something 

familiar to us that is very large can also be 

rediscovered in a corresponding form at 

the microscopic level. Take, for example, 

the comparison between a city and a cell: 

the cell’s equivalent to the city limits is the 

cell membrane, which delineates the cell 

from the external environment or from 

neighbouring cells; situated in the membrane 

are points of passage that allow for a 

controlled traffic of “goods”, such as one 

might find between neighbouring countries. 

Let’s continue with entities that are 

above the level of the State, such as the 

European Union (within which the borders 

have largely been raised). With a bit of 

imagination, you can also find their equivalents 

at the cellular level, for example in 

the skeletal muscles, where the individual 

cells are united together into associative 

units, the muscle fibres, in order to be able 

to work more effectively. So it’s not surprising 

that there are also correspondences 

in terms of energy-production and -transport 

at the cellular level, where terms such 

as “power station” and “energy transmitters” 

can equally be applied. 

Plant cells are characterised by the fact 

that they possess “solar panels”, the socalled 

chloroplasts. With the help of these 

cell organs (or “organelles”), they are able 

to capture light energy and convert it into 

other forms of energy that are useful to the 

plant, although not into electrical energy 

like our solar panels can, but rather into 

chemical energy, without which biomass 

could not be created. This ability makes 

plants the basis for all terrestrial life as we 

know it: all animals, including man, use 

the energy that plants fix and turn into biomass, 

either directly or indirectly, in order 

to maintain their own vital processes. This 

certainly applies to herbivores, which consume 

plants directly, but also to carnivores 

insofar as they survive by eating herbivores 

and even, in the end, to decomposers 

such as fungi, which gain the energy they 

need for their own metabolism through the 

degradation of organic matter. 

Natural solar panels 

Chloroplasts, the solar panels of the plant 

cell, are extremely complex units. Scientists 

speculate about their origin: like mitochondria, 

which we’ll talk about in more 

detail below, they possess their own ringformed 

DNA, similar to that of bacteria 

and blue-green algae. Chloroplasts are capable 

of multiplying independently within 

the plant cell. Thus the so-called endosymbiont 

theory suggests that chloroplasts 

were originally independent, blue alga-like 

organisms that were taken up by other single-celled 

organisms many aeons ago: but 

instead of being digested as food, they 

rather continued to live inside their new 

hosts in a symbiotic relationship. 

Within the chloroplasts can be found 

the thylakoids, rolled up membrane systems 

that look rather like a pile of coins. It 

is here that the light-absorbing agents are 

stored, particularly the green pigment 

chlorophyll. And it’s also here that the 

wonder of energy-capture and conversion 

occurs – photosynthesis. 

Sugar made from CO2 

The process of photosynthesis can be divided 

into three stages: 

• First, light (a form of electromagnetic 

energy) is absorbed; 

• The electromagnetic energy is converted 

directly into chemical energy; 

• Finally, the chemical energy is used in the 

production of organic matter and is thus 

made available for subsequent use within 

the cell. 

When light hits the thylakoid membranes 

in the chloroplast, it sets the electrons present 

in the absorbing pigments into a more 

excited, and thus more energy-rich, state. 

Excited electrons can be given up easily. 

Operating through several intermediate 

steps, electron transfer ensures that two 

molecules important to subsequent metabolic 

processes are formed – or to be more 

accurate, are regenerated – the energy-coupling 

agent ATP (adenosine triphosphate) 

and the reducing agent NADPH, a molecule 

with the rather challenging name of 

nicotinamide adenine dinucleotide phosphate 

hydrogen. 

With the help of ATP, the plant cell is 

able to synthesize the energy-rich substance 

glucose within its chloroplasts, using 

the energy-poor substances carbon 

dioxide (CO2) and water as building 

blocks. During this reaction, the water 

molecules are split into oxygen, electrons 

and hydrogen ions; NADPH is oxidized to 

NADP +, and energy-rich ATP returns to its 

low-energy form, ADP. The formula for the 

reaction is as follows: 

6 CO2 + 12 H2O ➞ 

C6H12O6 + 6 H2O + 6 O2. 

From six molecules of carbon dioxide 

and twelve molecules of water, a molecule 

of glucose arises, as a sort of energy-store; 

the by-products of this reaction are six 

2/08 COURIER 19

molecules of water and six molecules of 

oxygen. This oxygen is released into the 

surrounding air. The fact that our atmosphere 

today comprises about 20 percent 

oxygen is largely the result of millions of 

years-worth of photosynthetic activity. So 

people and animals owe not only the basis 

for their nourishment to plants, but also the 

air they breathe. 

Plants can synthesize glucose from CO2 

in one of two ways. In most crop plants, the 

intermediate molecules in the reaction 

have three carbon atoms (the so-called C3plants). 

In other species such as maize, elephant 

grass and sugar cane, CO2-fixation 

proceeds via oxalacetate, a compound with 

four C-atoms (C4-plants). This latter reaction 

is quicker, more efficient, and requires 

less water. C4-plants are therefore often 

used for producing biomass (energy 

plants). The temperature optimum for C4plants 

is higher than that of C3-plants, so 

Specimen of a plant cell 

Cell wall 


the former tend to grow in warmer climates. 

The working efficiency of photosynthesis 

is estimated at around 20-35 percent, 

depending on the wavelength of the absorbed 

light. The synthesis of a mole of 

glucose requires 8,000 to 14,300 kJ of light 

energy. 

Energy production in the 

mitochondria 

Let’s return once more to the endo-symbiont 

theory: plant cells benefit from the 

presence of chloroplasts because of their 

ability to capture the energy of light 

through photosynthesis and channel it into 

energy-rich organic substances such as 

glucose and starch (macromolecules comprised 

of many glucose units). When the 

cell needs energy – as it always does, to 

run metabolic processes, growth and cell 

Vacuole 

Cell membrane 

Mitochondria 

Smooth endoplasmatic 

reticulum 

division – then the glucose energy safe 

must be cracked. Just as for photosynthesis, 

the cell does this with the help of certain 

organelles that possess their own 

DNA, reproduce themselves independently 

and also appear to have an ancestry going 

back to bacterium-like predecessors – the 

mitochondria. These organelles are found 

in the cells of all complex organisms, in 

plants as well as in animals and fungi. 

Mitochondria are particularly numerous in 

cells that use a lot of energy, such as muscle 

cells, nerve cells and egg cells. 

In the mitochondria, the chemical energy 

stored in glucose or other organic substances 

is made available through oxidative 

degradation. With the release of energy, the 

cell’s battery – the ADP/ATP-System – is 

recharged. The complete oxidation of one 

mole of glucose delivers 38 moles of ATP, 

meaning that the efficiency of oxidative 

glycolysis lies at almost 40 percent – mak- 

Chloroplast 

Nucleus membrane 

with pores 

Ribosomes 

Rough endoplasmatic 

reticulum 

Microtubuli 

Golgi apparatus 

Lysosomes

ing it a pretty effective system, on a par 

with the energy yield of modern steam turbines. 

Thus the mitochondria really do 

earn their reputation as the cell’s powerhouse. 

During the oxidation of organic 

compounds, hydrogen is split off and 

brought together with molecular oxygen to 

produce water (4 H + O2 ➞ 2 H2O). The 

formation of water is the main energyyielding 

reaction. You could consider this 

process (cell respiration, as it is called) as 

being the opposite of photosynthesis: in 

the chloroplasts, glucose and oxygen are 

produced from CO2 and water (with sunlight 

providing the energy); whereas in the 

mitochondria, glucose and oxygen are degraded 

again to CO2 and water in order to 

release energy. 

Consequences for the farmer 

The growth and yield of crop plants will 

increase as the factors that are important 

for photosynthesis approach their optimum 

levels. Factors such as sunlight and temperature 

are of course beyond the farmer’s 

control (the temperature optimum for photosynthesis 

in full sunlight lies at 35°C). 

Drought has a negative effect on photosynthetic 

productivity because the plant protects 

itself from drying out by closing 

its stomata, thereby limiting the exchange 

of the gases necessary for this process. 

Given the facts of climate change, it is interesting 

to note that photosynthesis functions 

most efficiently at an ambient CO2concentration 

range of 0.1 to 1 percent. 

However, the CO2-concentration in the atmosphere 

currently lies at around 0.037 

percent (370 ppm), meaning that plants are 

working at below capacity. The anticipated 

increase in the concentration of the greenhouse 

gas CO2, which is expected to reach 

about 500 ppm in the course of the coming 

decades, is likely to boost the growth of 

plants to some extent. 

Laboratory studies have indeed shown 

that considerable yield increases (of 20-30 

percent) might be anticipated as the result 

of this so-called CO2-fertilising effect. But 

are these results really so easily translated 

from the laboratory to the field? On the 

other hand, would it really be possible to 

simulate an enhanced CO2-concentration 

in the field (for example over a cereal 

crop) in order to obtain a realistic picture 

in situ? 

The effort involved is considerable – 

but studies like this are indeed running at 

several sites around the world. One of 

these locations is the Johann Heinrich von 

Thünen-Institut (vTI), the former German 

Federal Agricultural Research Centre, in 

Brunswick, Germany. In the Brunswick 

carbon project, which is running over several 

cropping seasons, the CO2-concentration 

in the air above selected portions of a 

field is being maintained at a constant 450- 

550 ppm using controlled release of the 

gas. The scientists are measuring growth, 

but they are also monitoring other parameters 

such as the plants’ water balance. The 

results obtained so far are actually rather 

sobering: biomass production in wheat and 

sugar beet increased by a rather modest 

6-14 percent; at the same time, water use 

decreased. Moreover, protein content decreased 

by about 10 percent in the grain of 

winter barley, for example. Thus, the yield 

may increase, but the quality of the harvest 

also changes. 

This demonstrates once again how 

highly complex the metabolism of plant 

cells is; the capture, storage and use of 

energy are only three aspects among many. 

A glimpse into these biochemical processes 

is fascinating, but it quickly becomes obvious 

that it is not easy to intervene or indeed 

to steer them. And that’s another way in 

which a microscopically small cell is similar 

to a large municipality. ■

An end to the game 

Movento ® is the new innovative insecticide 

from Bayer CropScience. It moves 

easily within the plant, allowing it to reach 

insect pests that have burrowed deeply into 

the plant’s tissues. It is characterised by a 

broad and long-lasting efficacy, mainly 

against sucking insects. At the same time, 

Movento works hand-in-hand with beneficial 

arthropods and honey bees. 

Crop protection products must work. 

This is a rather obvious statement – but it 

encapsulates the challenge that keeps 

thousands of researchers around the world 

occupied for entire careers. It isn’t just a 

matter of rendering the pest harmless 

through contact with, or uptake of, the 

active substance: the active substance first 


has to reach the pest. If insects are lodged 

deep inside plant tissues (for example in a 

lettuce heart or at the ends of roots), the 

challenge may be a considerable one. 

With its new insecticide Movento, Bayer 

CropScience now has a trump card in its 

hand. “There’s no escaping this product – it 

penetrates through to the remotest parts of 

the plant, providing reliable control of pests”, 

says Emmanuel Salmon, Product Manager 

for insecticides at Bayer CropScience. The 

active substance spirotetramat spreads 

throughout the entire plant – it simply 

reaches every part, from root tissues to 

young, developing shoots. Spirotetramat’s 

movement up and down the plant is continuous, 

so it eventually becomes distributed 

evenly throughout the plant’s tissues. This 

is what sets it apart from almost all the insecticides 

that have appeared on the market 

so far. As Emmanuel Salmon points out, 

“Movento is currently the only modern insecticide 

that is able to ride the plant’s bidirectional 

transport system.” 

Integrated Crop Protection 

with Movento 

Bayer CropScience’s scientists are especially 

proud of the fact that besides being extremely 

effective against insect pests, 

Movento also possesses remarkable environmental 

properties. Movento can be considered 

safe to populations of beneficial

of hide-and-seek 

arthropods. There were no long-lasting, adverse 

effects on beneficial bugs, lacewings, 

spiders, earwigs, ladybird beetles or trichogramma. 

Furthermore, there was no longer 

lasting effect on predatory mites. Moreover 

large scale, internal field tests also demonstrated 

safety to honey bees as long as the 

product is used correctly. This good selectivity 

discloses manifold options for the 

combined use of this product with beneficials. 

Movento can be highly recommended 

for the use in Integrated Pest Management. 

The active substance’s really innovative 

property is its ability to move within both 

the upward-bound water column, and the 

assimilate stream that moves mainly in the 

opposite direction. Systemic insecticides 

from older chemical classes have so far 

only been able to move in the water column; 

they have therefore been unable to 

reach all parts of the plant. But insect pests 

have now lost their hideaways. 

New tool for resistance 

management 

The active substance spirotetramat 

derives from the young chemical class of 

ketoenols, two other representatives of which 

are now well-established under the tradenames 

Oberon ® and Envidor ®. Spirotetramat 

excels through its broad spectrum of activity 

against sucking insects. These include 

aphids, thrips, planthoppers, vine lice, mealy- 

bugs, whiteflies and scale insects. The use of 

this active substance is most profitable in intensively-managed 

crops such as vegetables, 

citrus, pome and stonefruits, nuts, grape, hop, 

potato, tropical fruits, cotton and soybean. 

Movento’s active substance inhibits lipid 

synthesis in sucking insect pests. It is particularly 

effective during the insects’ early 

developmental phases; larvae are unable to 

move after ecdysis, and they eventually dry 

out. But adult insects are also affected insofar 

as their fertility is reduced. The pests’ 

typical explosive population growth, which 

can otherwise be relied upon to occur as 

soon as environmental conditions become 

favourable, simply breaks down. 

“As no other known classes of active 

2/08 COURIER 23

substance interfere at this particular point 

in the insect’s metabolism, Movento can be 

an important tool for effective resistance 

management.” says Karl Muenks, Project 

Leader for spirotetramat at Bayer Crop- 

Science. Farmers and horticulturalists 

around the world have observed that pest 

insects often become gradually less sensitive 

to substances belonging to chemical 

classes that have been represented on the 

market for a long time. Trials with Movento 

have demonstrated its strength here – 

researchers have so far failed to find any 

indication of cross-resistance, even in 

aphids and whiteflies that are highly resistant 

to other compounds. Product Manager 

Emmanuel Salmon advises that in order to 

preserve the long-term effectiveness of this 

new class of insecticides, “Movento should, 

wherever possible, be used in alternation 

with products from other chemical classes, 

and on no more than two occasions within 

a growing season.” He continues: “Because 

the conditions associated with the 

application vary greatly from region to region 

and from year to year, we recommend 

contacting the local Bayer agronomic advisor 

for advice, especially with regard to 

avoiding resistance development.” 

Reduced number of applications 

One of Movento’s greatest benefits is its 

longevity of action – it can protect a crop 

from pest infestation for several weeks: 

even insects that attack plants after treatment 

are affected. Together with optimal 

distribution within the plant via bi-directional 

systemic movement, this offers users 

Whiteflies Aphids Scales 


the option of reducing the total number of 

applications. Moreover, this innovative insecticide 

possesses favourable residues 

and breakdown profiles. “Movento is the 

ideal insecticide for farmers running integrated 

crop protection programs”, concludes 

the Bayer Product Manager. 

These particularly positive properties 

are of course relevant not only to users, but 

also to the international food-chain, with 

its high standards of quality. Free trading 

of farm products requires that maximum 

residue limits and import tolerances are 

being held to. Movento’s ability to meet 

these requirements if used as recommended 

on the label has already been demonstrated 

– and confirmed by the US Environment 

Protection Agency, among others. 

“With Movento, producers have a tool to 

help them to produce high-quality fruit and 

vegetables. Food traders and consumers 

are entitled to expect healthy, safe and op- 

An overview of Movento’s strengths: 

tically-attractive products – Bayer’s crop 

protection innovations make a valuable 

contribution towards achieving this”, explains 

Karl Muenks. 

As market introduction has already taken 

place in many countries, and is imminent 

in others, Emmanuel Salmon has plenty to 

do at the moment. The very first registration, 

which was achieved in Tunisia at the 

end of 2007, was followed in summer 2008 

by further registrations in the USA, Canada, 

Turkey, West Africa, Morocco and New 

Zealand. “By 2010, Movento will be in use 

in more than 70 countries. Its tangible advantages 

for users, the trade, processors 

and consumers mean that it presents an attractive 

alternative to the standard options.” 

Product Manager Salmon is therefore 

firmly convinced that Movento will 

soon be gaining considerable market share 

in fruit and vegetable crops. ■ 

• The active substance spirotetramat belongs to the new chemical class 

of the ketoenols, and possesses a new type of mode of action. 

• No cross-resistance with the standard classes of active substance 

• Broad activity against sucking insect pests 

• 2-way systemicity for optimum distribution within the plant 

• Long-term protection 

• Spares beneficials, working hand-in-hand with them 

• Fulfils the expectations of the food chain and environmental protection 

requirements.

2-way systemicity 

Conventional systemic insecticides work according to the 

following principle: the active substance is taken up 

through the leaves and distributed through the plant, 

predominantly via the xylem. The xylem cells provide a 

transport path for water and nutrients taken up by the 

plant’s roots; the transport stream is driven by the suction 

effect caused by the evaporation of water through stomata 

on the leaves. This means that the conventional insecticides 

can only be distributed in one direction – towards 

the point of evaporation. Remote tissues such as the 

roots, newly developing tissues, or innermost leaves (for 

example in a head of lettuce) cannot be protected properly 

from pest insect attack. Things are different with 

spirotetramat: instead of being restricted to this one-way 

traffic, it can move in both directions by virtue of its ability 

to be transported in both the xylem and the phloem. 

Assimilates and other organic compounds move up and 

down within the plant’s phloem cells – between the roots 

and the shoot tips, young buds or fruits. This means that 

even insects hidden in the inner leaves of a lettuce or 

cabbage head, or those hidden under the bark of a fruit 

tree, can be controlled effectively. Spirotetramat’s excellent 

mobility also ensures that plant tissues formed after 

treatment are equally well protected. 

A: Translocation pattern of 

a typical one-way systemic 

insecticide 

Mealy bugs Psyllids 

B: Movento ®’s two-way 

systemicity 

2/08 COURIER 25

Soybeans in Brazil 

Atento, a new 

solution for managing 

Asian rust 

The benefits of soybean production for the Brazilian economy are 

undeniable. It is currently the country’s most important crop, representing 

a dynamic element in industry, trade and services. 


Soybean leaf with rust Soybean plants destroyed by the disease

Soybean growing accounts for 12 percent 

of the Gross Domestic Product of Brazilian 

agribusiness. Soybeans are becoming a 

fundamental generator of wealth; this crop 

is seen as an opportunity to develop several 

regions of the country, for example the 

West Central region. 

According to the national supply company 

CONAB, the area under soybean cultivation 

in the 2007/2008 season was more 

than 21 million hectares, 2.3 percent 

(471.7 thousand ha) more than in the previous 

season. The good climatic conditions 

have generally favored agriculture; the 

country’s mean production of soybean has 

risen from 2,823 kg/ha to 2,835 kg/ha, and 

total production from ca. 58.4 million 

tonnes to nearly 60 million tonnes, making 

Brazil the second largest producer of this 

grain in the world. 

However, the economic viability of the 

soybean crop has been put to the test during 

recent harvests. The devaluation of the 

Brazilian Real and significant increases in 

production costs have increasingly put 

farmers under pressure. 

Asian rust 

Among the main factors reducing productivity 

are certain diseases that have been 

occurring with increasing frequency and 

severity. The most important of these is 

Asian rust (Phakopsora pachyrhizi), which 

has been worrying farmers and technicians 

since 2001. 

Considered the worst disease of soybeans 

worldwide, Asian rust originates from the 

East (Japan), and has traditionally been 

present in most Asian countries and Australia. 

However, Asian rust was detected 

for the first time outside that region in 

1994, in Hawaii. It was recorded for the 

first time on the African continent in 1996, 

Lack of control can lead to dramatic harvest losses. 

causing severe damage in experimental 

plots in Uganda; it reached plantations in 

Zimbabwe and Zambia in 1998 and in 

South Africa in 2001. That was also the 

year of its first detection on the American 

continent, in Paraguay and in the south of 

Brazil. Since then, it has spread to all soybean-producing 

countries on the American 

continent. In Brazil, the disease is present 

in every area of soybean cultivation. 

The importance of Asian rust in Brazil 

can be understood by considering its rapid 

spread, its virulence, and the significant 

amount of damage it causes. The estimated 

total financial penalty resulting from rust 

outbreaks in the period from 2001 to 2005, 

including grain losses, the cost of control 

measures, and losses of incidental taxes 

collected on the grain, was more than US$ 

7.7 billion. In 2006/07, the cost of grain 

losses plus the cost of control measures 

amounted to US$ 2.2 billion. 

Since it was first identified in 2001, rust 

has shown its ability to spread and destroy 

all too clearly: it punishes farmers who fail 

to control it. Each year, its severity increases 

in the regions in which the conditions 

are favourable for outbreaks. Despite 

the reduction in the price of most fungicides, 

the overall cost of control has risen, 

because of the increasing number of applications 

that are needed. 

Control problems 

Since the first outbreaks in Brazil, there 

have been growing numbers of complaints 

concerning reduced efficacy of control and 

the lower residual duration of some fungicides 

with sequential applications now being 

made at very short intervals of between 

seven and 12 days, whereas the norm 

would be something around 21 days. There 

are a number of causes contributing to de- 

ficiency of control: continuous production 

of inoculum in irrigated areas by intercropping 

soybeans for seed production during 

the winter (“green bridge”); failure to 

identify rust correctly at the early stages of 

infection; inappropriate timing of application; 

inadequate equipment; under-dosing 

and/or low spraying volume; inadequate 

leaf coverage; excessive rain, making 

spraying difficult or even impossible; and 

large cultivation areas which make it difficult 

to apply products at a suitable time. 

Atento 

Effect of Atento on the development of soybean rust 

70 

60 

50 

40 

30 

20 

10 

0 

% Infections of soybean rust 

Recognizing this situation, Bayer Crop- 

Science developed a new solution for the 

control of Asian rust specifically for Brazil 

and the country’s soybean-growing industry. 

Atento ® is the first-ever seed treatment 

product available for combating this devastating 

disease, and it represents an important 

element in integrated crop protection. 

Fluquinconazole, the active substance in 

Atento, has systemic and residual activity, 

so it is able to protect the crop’s lower 

leaves, thus delaying the development of 

the rust epidemic. 

The seed-treatment supports the first 

spray applications, providing greater flexibility 

and security in situations where the 

producer does not always manage to apply 

foliar sprays at the right stage, often due to 

adverse weather conditions, lack of available 

machinery, size of the area to be treated, 

etc. Therefore, Atento is becoming an increasingly 

important tool in the fight 

against Asian rust. It is used at a dose rate 

of 300 ml/100 kg seed, always in combination 

with a follow-up spray program, together 

with appropriate cultivation methods. Atento 

is recommended by the country’s most important 

official advisory body, Embrapa 

Soybean. ■ Luiz Weber 

untreated 

Foliar Fungicide 

Atento + Foliar Fungicide 

56 DAP 69 DAP 78 DAP 84 DAP 91 DAP 

2/08 COURIER 27

40 years 

of Betanal 

Gaining the 

advantage 

through 

innovation 


Milestones in Betanal-research

Forty years ago, the 

then new product 

Betanal ® entered the 

market. In the inter- 

vening years, Bayer 

CropScience has been 

steadily optimising this 

post-emergenceherbicide 

for sugar 

beet cultivation through 

the advantages of 

Beta Technologies. 

Sugar beet cultivation used to be an onerous 

task. The plants had to be singled-out 

by hand in order to obtain the best density 

from an agronomic point of view. And until 

a few decades ago, weed control was 

done exclusively by mechanical means; 

workers had to go through the field several 

times during a growing season in order 

to keep it free of weeds. In many cases, the 

entire family would be kept busy doing this 

hard work for days on end. Moreover, the 

beet plants themselves were often damaged 

during these operations. 

It took a long time to find a selective 

herbicide that did not damage the particularly 

sensitive beet plants. So it was almost 

a sensation when Betanal came onto the 

market in 1968, for this was the first herbicide 

to make post-emergence control of 

weeds possible without affecting the sugar 

beet crop. The Beta part of the name was a 

reference to the plant that needed protection, 

Beta vulgaris; the nal part was simply 

an abbreviation of the German-language 

name for the timing of treatment: Nachauflauf 

(= post-emergence). 

The two to three applications per season 

were now enough to keep the major part of 

the weed threat reliably at bay. Betanal initially 

entered the markets in Germany, 

France and Japan, but it later became the 

generally accepted standard for weed control 

in sugar beet around the world. 

Steady flow of improvements 

Since its introduction in 1968, the product 

has undergone many rounds of improvement 

in terms of its properties and the possibilities 

it offers. Over the years, Bayer 

CropScience Development scientists have 

been able to create a family of Betanalcontaining 

ready mixtures, thus providing 

beet growers with customized solutions for 

their weed problems. Today, Betanal products 

are on the market in more than 40 

countries – in other words, wherever the 

cultivation of sugar beet is of economic 

importance. 

Through all the improvements that have 

been introduced, phenmedipham, the active 

substance in the pioneer product of 1968, 

has remained an important component of 

the mixture. “In all this time, there has not 

been a single observation of resistance to 

this active substance”, comments Jaroslava 

Govorovska, Global Product Manager for 

Betanal at Bayer CropScience. “Indeed, 

this also applies to desmedipham and ethofumesate 

– the other two important Bayer 

CropScience active substances that have 

been used in Betanal mixtures over the 

years.“ 

The most important product in most 

countries these days is Betanal Expert, a 

combination of all three active substances, 

i.e. phenmedipham, desmedipham and ethofumesate. 

Govorovska continues: “This 

combination has been brought together in a 

high-quality formulation, which provides 

for ease-of-use and reliable weed control, 

whilst at the same time ensuring excellent 

compatibility with the beet crop.“ 

2/08 COURIER 29

Formulation in focus 

The formulation has been a central theme 

in the story of Betanal’s continuing development. 

“An herbicidal active substance 

such as phenmedipham can only express 

its full activity if it is delivered in a welltested 

formulation”, says Govorovska. “Efficacy 

gains within the Betanal product 

range have often been the result of innovative 

formulation concepts.” For example, 

one milestone was the introduction in 1996 

of Betanal Progress OF, a plant-oil based 

formulation that improved the distribution 

of the active substance on the leaf surface, 

thereby allowing an increase in efficacy to 

be achieved at a lower application rate. 

Development work in the area of postemergence 

herbicides in sugar beet cultivation, 

which is now entering its fifth decade, 

has also got a name: Beta Technologies – 

Competence in Beets and Weeds. On the 

basis of this competence, Bayer continues 

to develop new sugar beet herbicides for 

optimized weed-control that offer flexibility 

in terms of mixtures and usage, and possess 

an excellent environmental profile. 

In 2002, Bayer CropScience brought the 

newest product onto the market: Betanal 

Expert. This was the first example of the 


use of the so-called advanced micro-droplet 

technology, which brings a further increase 

in efficacy. The technology ensures 

that small droplets containing dissolved 

active substance develop within the spray 

emulsion; these subsequently become very 

finely distributed on the leaf. “This results 

in a particularly good, even distribution of 

the active substance on the target weeds, 

and thus optimal uptake by these plants”, 

explains Dr. Gerhard Johann, the Product 

Development Manager responsible for the 

technical development of sugar beet herbicides 

at Bayer CropScience. 

The steady process of improvement 

means that Betanal Expert is markedly 

more efficient than its predecessors. These 

days, only 900 grammes of product need to 

be applied per hectare within a season. That’s 

less than half the amount of active substance 

needed in 1968. Despite the reduced 

application rate, weed control is excellent 

– with a typical average efficacy against 

target weeds of 95 percent control (in 1968, 

the figure was around 65 percent). 

But it isn’t just the efficacy that has 

been improved over the years. Development 

scientists have always paid particular 

Jaroslava Govorovska, Global Product Manager for 

Betanal at Bayer CropScience, moderated the Future 

of Sugar Beet Forum in Berlin.

More than 200 sugar beet specialists from 18 countries met at the Future of Sugar Beet Forum in the Bayer 

Schering Pharma buildings in Berlin at the beginning of November. This is where the first market launch of the 

beet herbicide Betanal was announced 40 years ago. Bayer CropScience marked the occasion by inviting the 

delegates to come to the Forum to discuss utilization, marketing and future perspectives of sugar beet and its 

products with the experts. 

Following a continuing series of improvements 

over the years, Betanal Expert 

is more efficient than its predecessors: 

today, 900 grammes of active substance 

per hectare are sufficient to control 95 

percent of the weed population. In 1968, 

more than double this amount of active 

substance was needed to achieve a 

mere 65 percent control. 

attention to the quality of the formulation. 

And they’ve achieved a great deal as a 

result: “The formulation scientist’s worst 

nightmare is when the active substance 

crystallizes out – but we’ve had this particular 

problem under control for years now”, 

notes Dr. Frank Sixl of Bayer Crop- 

Science’s Formulation Technology Department, 

who works on the further development 

of Betanal. Premature crystallizingout 

of active substance from the spray solution 

increases costs and wastes time for 

the user: sieves within the spray equipment 

become blocked, meaning a greater cleaning 

effort. And most importantly, the efficacy 

of the application is also reduced. 

This constant process of product optimization 

has helped Bayer CropScience to 

maintain its position as global market 

leader in the sugar beet post-emergence 

herbicide sector since 1968. “Sugar beet 

growers associate the name Betanal with a 

product that continues to be developed, 

meaning that Bayer CropScience’s latest 

technologies can be implemented to solve 

their current weed-control problems”, 

states Jaroslava Govorovska. In order to 

keep this success story going, the Betanal- 

Team is already working on the next generation 

of products. ■ 

Karl Hübner 

2/08 COURIER 31

Nature and technology 

Considering their length, cereal stalks are very thin – but nevertheless 

amazingly stable. They carry the ears and wave in the wind without 

buckling. The construction of grass stalks combines stability with flexibility 

in a very special way. 

Many television towers owe their design to cereal stalks. In contrast to 

their archetypes in nature though, television towers should not sway too 

much in the wind. A certain amount of movement is acceptable – it actually 

prevents the tower from buckling and falling over as soon as there is a 

gust. So television towers are not built to be entirely solid and inflexible. 

Engineers provide them with a widening base in order to increase their 

stability. But cereal stalks can do without this particular enhancement. ■ 

www.bayercropscience.com

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