Kai kurių insekticidų įtaka vasarinių rapsų derlingumui

Abstract

The aim of this investigation was to identify the impact of five insecticides Mavrik, Proteus, Fury, Karate and Fastac on yield of spring rape. The experiment carried out in Pagausantis I village, Jurbarkas region in 2010. During the field trial two observations were made. The alternation of the number of flea beetles (Phyllotreta spp.) was studied using Petliuk box. The alternation of the number of pollen beetles (Meligethes aeneus F.) was studied using stack made of wooden timber which walls were made of polythene. During field trial it was found out that only pollen beetles reached the point of economic malifecence. At that day the field was sprayded one time with insecticides. Immediately after spraying of insecticides started the observation of pollen beetles. Observation had lasted for few weeks. It was found out that all insecticides reduced the number of pollen beetles. The best results were showed by insecticide Fastac. The effectiveness of this insecticide was confirmed when the analysis of summer rape's yield was made. Assay showed that all insecticides had good influence on summer rape's yield. Due to the use of insecticides there was recieved 530-692 kg ha' appendage of rape's yield. The best results were showed again by insecticide Fastac