Bemisia tabaci (Gennadius) elicited leaf chlorophyll loss in blackgram (Vigna mungo (L.) Hepper)

The effect of feeding by whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleryrodidae) on chlorophyll loss was quantified from the leaves of nine blackgram (Vigna mungo (L.) Hepper) genotypes over a period of two seasons. The chlorophyll content indices declined significantly in all the genotypes under whitefly-infested conditions, both at 30 and 50 days after sowing (DAS) particularly in the lower canopy of the plants. During both seasons, the moderately resistant genotypes (NDU 5–7 and KU 99–20) recorded lowest per cent decrease in the chlorophyll content, whereas highly susceptible genotypes (KU 7–504 and KU 7–505) recorded highest per cent decrease in the chlorophyll contents under whitefly-infested conditions.