Spray of Neem Leaf Extract Decreases the Leaf Sugary Incidence and Aphid Populations on Sorghum Leaf

Abstract

ABSTRACT
In the present study, the effect of Neem leaf extract on leaf sugary disease and aphid populations on sorghum leaf was studied using different concentrations of NLE (aqueous), viz., 10%, 20% and 30% along with the water spray and control blank. In Rabi 2005 on 45th day, percent disease incidence was 71.6% and in 30% NLE-treated plant, it was 27% with percent inhibition of 63%. In Rabi 2006, disease incidence of LSD was 52.4%, whereas NLE 30% treated plant was having reduced percent disease incidence of 11.2% with percent inhibition of 78.7%. Before starting with NLE, the aphid population on sorghum leaf was 385/sq cm of leaf area. After spray treatment using 10% of NLE, the aphid population decreased to 213/sq cm of leaf area (55% inhibition). Further, the spray of 20% and 30% of NLE resulted in decrease of 145/sq cm leaf area with 68% inhibition and 108/sq cm of leaf area with 74% inhibition, respectively. When compared to control, 30% of NLE is most effective in reducing aphid population on leaf surface. Hence, NLE is one of the very effective botanical pesticides, which can be used in management of sorghum aphids.
Keywords: Neem, leaf sugary disease, sorghum, aphids