Study on the Influence of New Biologically Active Substances on the Grain Yield and Density of Acyrthosyphon Pisi Kalt. (homoptera, Aphidodae) in Spring

With the purpose of studying new biologically active substances in spring forage pea, during the 2007-2009 a two-factor field trial was carried out in IFC, Pleven. The biologically active substances Atonic (growth stimulant) – 0.06 l/da, Masterblend (combined leaf fertilizer) – 160 g/da and Confidor 70 WG (700 g/kg imidacloprid) – 15 g/da (an insecticide) were applied once (at the stages of budding and flowering) and twice (at budding and flowering). As a result of the conducted study, it was found that the biologically active substances, used alone and in combination, had a positive effect on the grain formation in spring forage pea. The yield increase varied from 3.8 tо 26.3% and it was highest in treatment with the combination of Confidor and Masterblend. The combined use of BAS was more efficient than their application alone. The Confidor efficacy (applied alone and combined) against Acyrthosyphon pisi varied from 79.8 tо 100.0% and decreased its density by 34.9 tо 55.4%. The highest efficiency was found for the combination of Confidor with Atonic and Confidor with Masterblend. The most pronounced decrease in pea aphid density was found for the combination of Confidor with Masterblend (55.4% decrease) and Confidor with Atonic (50.5% decrease), which determined the most highest plant productivity.