Abstract:
In this paper, we present results of two years study, in the field conditions, at NARDI Fundulea, located in the southeast of Romania, concerning the effectiveness of the biological control of the maize leaf weevils (Tanymecus dilaticollis
Gyll) at maize crops, with organic insecticide on a base of plant extracts from the Fabaceae family (0.3 %) applied
both, like seed coating and foliar spray. It has assessed weevils attack intensity at maize plants on a scale from 1 (plants
not attacked) to 9 (plants complete destroyed), saved plants percent at 30 days from maize emergence and plants height
at 50 days from plants emergence. At maize untreated plants, the weevils attack intensity was 3.16 in 2020 and 5.71 in
2021, while at variants treated with organic insecticide on a base of plant extracts from the Fabaceae family the weevils
attack intensity ranged from 3.08 to 3.14 in 2020 and from 5.65 to 5.68 in 2021. The lowest value of the weevils attack
intensity was registered in the case of the variant with seeds treated with imidacloprid active ingredient (I=2.56 in 2020;
I=4.46 in 2021). The highest values of saved plants percent were registered in the case of the variant with seeds treated
with imidacloprid (94.04 % in 2020, respectively 86.80 % in 2021). In this two-year study, in field conditions, in the
southeast of Romania, it hasn’t registered significant statistical differences concerning weevils attack registered at
untreated maize plants and maize variants treated with organic insecticide on a base of plant extracts from the Fabaceae
family (0.3 %). Both years haven’t registered significant statistical differences concerning plant heights at 50 days from
the maize emergence.
