Influence of Sowing Dates and Host Crops on Population Incidence of Whitefly, Bemisia tabaci (Gennadius) in Greengram and Blackgram

Abstract

Considering sowing dates and host crop affects population incidence of whitefly in greengram and blackgram, the present study was undertaken with four different dates of sowing at 10 - day interval: 24 July, 3 August, 13 August and 23 August 2019 with two varieties of greengram (IPM 205 - 7 & DGGV 2) and one variety of blackgram (IPU 94 - 1). Whitefly population varied significantly amongst the crops sown on different dates. Delay in sowing by 10 days (24 July?3 August), significantly increased the number of whiteflies from 3.68 to 4.52 adults per plant in IPM 205 - 7 (greengram), 7.38?14.52 adults per plant in DGGV - 2 (greengram) and 28.46?31.7 adults per plant in IPU 94 - 1 (blackgram). Peak population was observed in the 36th Standard Meteorological Week (3?9 September) and started declining thereafter. Preference of whitefly towards varieties studied was in the order of IPU 94 - 1 (blackgram) [ DGGV - 2 (greengram)] [ IPM 205 - 7 (greengram)].