TABLE CONTENTS

Control of Meloidogyne incognita on Tomato Grown in Artificial Substrate,
using Bio-rational Pesticides
Ploeg, A. & S. Edwards
Department of Nematology, University of California Riverside, Riverside, CA92521, USA.
To avoid soil-borne pests and diseases in greenhouse production systems, crops can be grown
in different types of soilless artificial substrates. Although providing a clean substrate at
planting, there is a serious risk of spreading diseases or pests that are introduced into the
system throughout the culture, because irrigation water is commonly re-circulated. Little is
known about the suitability of artificial substrates as an environment for plant-parasitic
nematodes. However, we recently encountered a severe infestation of root-knot nematode (M.
hapla) on roses grown in glass wool (Rockwool) mats. A study was initiated to evaluate
the efficacy of several biologically based (bio-rational) products to control root-knot
nematodes post-plant in glass wool. Tomato and M. incognita were used as a model system.
Of the products tested, abamectin was most effective in controlling M. incognita infestation
of tomato, but only when applied shortly after nematode inoculation. Soaking transplants in a
product containing Neem tree extracts, 1 week before transplanting into nematode inoculated
glass wool blocks, also reduced infestation. Only the oxamyl control treatment reduced
nematode numbers and tomato root-galling in an established infestation.
Chemical Controls for Nematodes in Protected Cultivation in Israel
Oka, Y.
Nematology Unit, Gilat Research Center, Agricultural Research Organization, M. P. Negev 85288, Israel
Several effective soil fumigants and nematicides were developed between 1940 and 1970.
Without a doubt, these chemicals were instrumental in ensuring food supply for the growing
human population during the last half century. However, several effective nematicides have
been withdrawn due to environmental and food-safety considerations. Since the phase out of
methyl bromide, the most effective soil fumigants for a wide range of soil-borne pathogens
and weeds, alternative chemicals and control methods have been evaluated for their
effectiveness in control of nematodes and other soil-borne pathogens. Only a small number of
new nematicides and soil fumigants have been released or are now in the registration process.
In Israel, combinations of these few chemicals are currently used for control of nematodes in
protected cultivation of crops including: tomato, bell pepper, cucumber, herbs and flowers.
These crops are often attacked by root-knot nematodes, mainly Meloidogyne javanica. The
most common strategy is pre-planting application of methyl isothiocyanate (MIT) or 1, 3-D
based soil fumigants combined with non-fumigant nematicide application during the growing
period. Formalin, which may suppress biodegradation of fumigants, is sometimes used to
enhance the efficacy of MIT based fumigants. However, soil fumigation alone does not
always keep nematode populations below threshold levels until the end of growing periods.
Non-fumigant nematicides based on organophosphates or carbamates, such as fenamiphos,
cadusafos and oxamyl, are applied during the growing season, if allowable according to
chemical residue levels. A new nematicide belonging to the fluoroalkenyle group has been
tested for its efficacy against M. javanica. The nematicide kills the nematode rather than
nematostatic action, and is in the registration process. Registration of methyl iodide, a
promising soil fumigant with broad-spectrum control of soil-borne diseases, weed seeds,
insects and nematodes, is to be initiated this year.
5 th International Congress of Nematology, 2008 102