Studies on novel approaches for the management of greenhouse whitefly Trialeurodes vaporariorum Westwood on tomato under protected environment

Abstract

Present investigations were carried out in the laboratory, outdoor insect rearing facility and naturally ventilated newlinepolyhouses at CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur during 2020-22. Studies on the effect of different levels newlineof recommended dose of fertilizers (nitrogen, phosphorus and potassium) on growth and development of greenhouse whitefly newlinereared on tomato revealed the duration and survival in different developmental stages was influenced adversely by decreased newlinenitrogen and increased potassium levels. Total development period during first generation lasted for 23.33 to 27.33 days at newline28±2°C temperature and 70±5% relative humidity in thirteen evaluated treatments, being maximum in treatment comprising newline200% NK+ 100%P,25%N+100%PK and 200%K+100%NP of RDF, respectively. Whereas during second generation it varied newlinefrom 19.67 days to 28.67 days, maximum duration corresponded to the treatment having higher levels of K, 200%K+100%NP of newlineRDF followed by 25%K+100%NP of RDF. Total survival to adult stage during GI ranged between 25.67 to 58.67%. Whereas, in newlineGII survival to adult stage ranged between 25.67 to 64.67%, being more in treatments comprising higher N levels i.e. 200% N newline+100 %PK being at par to 150% N +100 %PK of RDF. The minimum survival was recorded in treatments having lower levels of newlineN, 25% N +100 %PK of RDF. Plant nutrition also influenced the pupal length and breadth significantly which varied from 0.665 newlineto 0.732 mm and 0.362 to 0.461 mm, respectively in GII and was maximum in 200%N+100% PK. The minimum mean length and newlinebreadth was recorded in treatment comprising 25%NK+100%P during both the generations. Effect of plant nutrition on fertility newlineparameters of greenhouse whitefly adults assessed during GII revealed increasing K and decreasing N nutrition levels influenced newlinethe fertility parameters adversely. It was observed that increased level of K (200%K+100%NP, 150%K+100%NP) resulted in newlinereduction in gross reproductive rate (GRR), net reproductive rate (R0), true intrinsic rate of