[Involvements of bio-ecological factors in the integrated control system of pests in wheat crops in central Transylvania]
1998
Matschi Dana | Mustea D. (Institutul de Cercetari pentru Cereale si Plante Tehnice, Fundulea (Romania))
Drawn up following investigations performed in 1987 - 1996, the paper presents a series of ecological factors involved in evolution of pest populations level and in causing damages in wheat crops. Among the factors under study reference is made on diversity of pests (64 species) and on beneficial Arthropod fauna (more than 40 species). According to their bio-ecology and damages the most important pests were: Diptera species (Opomyzdae, Anthomyiidae, Chloropidae), Homoptera (Cicadina and Aphidina), Thysanoptera and Coleoptera (Chrysamelidae).Under favourable agrotechnological conditions, wheat plants attacked manifested compensatory reaction of yield losses. After the spring outbreak of Dipterans (Opomyza florum, Delia coarctata, Phorbia securis), in crops with 10 - 24 percent attacked plants yield losses recorded can range between 300 and 1.500 kg/ha, in various wheat cvars. The compensatory effect was recorded at 60-80 percent. The attack by Lema melanopus larvae in grain crops (with overpassed density economic threshold) induced yield losses of 14 - 62 percent. Natural biological control of ear pests (aphids and thrips) by means of polyphagous predators, was involved to 13.47 percent in wheat yield increase. This paper presents efficacy of some insecticides in controlling the main pests and the side-effects of insecticides on the beneficial Arthropod fauna.
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