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soil during the sprouting period, this density varying between 12 – 16 larvae of different
ages / m². Moreover, important damages are caused by the larvae of the turnip moth
(Agrotis segetum), which, due to their accentuated polyphagism, bring about damages
not only in maize crops, but also in beet, potato and leguminous plants. The density of
the butterflies caught by the pheromonal traps varied from one month to another,
reaching a peak during the flight period.
b.) Plant pathogens: Regarding the culture of winter wheat, the structure of the
complex of pathogens underwent modifications as to the cultivated species, as well as to
the climatic changes. The last 5 years, having had a rather droughty character, have
been less favorable to pathogen infections, favoring the proliferation of insects instead.
Table 3. The main winter wheat diseases in the Romanian Western Plain
Symptomps Disease
Cause agent Economical
expressed on: common name
importance
Leaves Barley Yellow
Dwarf
BYDV medium
Leaves Powdery Erysiphe graminis f.sp. low
mildew tritici
Leaves leaf spot H. tritici-repentis medium
Leaves leaf rust Puccinia recondita low
Leaves stripe rust P. striiformis variable
Seed / head head blight Fusarium spp. medium
Head common bunt T. foetida, T. Caries variable
Lower stem eyespot Pseudocercosporella
herpotrichoides
variable
Lower stem sharp eyespot Rhizoctonia sp. low
The symptoms of barley yellow dwarf virus were frequently identified between the
years 2000-2002, when the installation of vectors (Aphidae) in autumn was noticed in
strongly developed crops. Because no control is available for many viral diseases, such
as barley yellow dwarf, we must supervise the installation (and, when needed, the
fighting) of vectors.
Of the foliar diseases, the importance of the powdery mildew (Erysiphe graminis)
decreased, while that of the yellow leaf spot (Helminthosporium tritici-repentis Died.)
increased, the symptoms of the latter on the upper leaves being easily mistaken for the
effects of the drought. The pathogen is causing, in the current conditions, the greatest
yield losses (up to 250-350 kg/ha), associated with the reduction of seminal quality.
Fungicidal treatment with systemic fungicides, according to regional advice at heading,
balanced fertilisation can contribute effectively to the limitation of losses.
The brown leaf rust (Puccinia recondita) has been present every year, without
affecting more than 5 % of the leaves’ area of assimilation. The stripe rust (Puccinia
striiformis) appeared on some very susceptible wheat species, at the end of the
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