Impact of Feretilizers Application on Insect Pests Populations in Okra, Abelmoschus Esculentus L. Crop

Abstract

The experiment on the impact of fertilizers application on insect pests’ population in okra crop was conducted at the experimental fields of Faculty of Crop Protection, Sindh Agriculture University, Tando Jam during the Spring season 2006. Okra variety “Subzpari” was cultivated in a completely randomized block design with four treatments and three replicates. The treatments were: T1= urea, T2= DAP (Diamunium phosphate), T3= urea + DAP and T4= control. The population of jassid and whitefly was counted by examining thirty randomly selected leaves from each sub plots. The populations of Helicoverpa armigera Hb. and Earias spp. were recorded from 30 randomly selected plants from each sub plot. The results showed that sucking insect pests i.e. jassid and whitefly appeared on the crop just after transplanting until harvest. The populations of chewing insects i.e. H. armigera and Earias spp. were found very negligible. The amximum population of jassid (4.62 ± 0.52 per leaf) was recorded on the plants treated with DAP, followed by urea (4.20 ± 0.32), urea + DAP (3.99 ± 0.50) and control (0.11 ± 0.41). The overall results showed that the highest population of jassid (1.05 ± 0.66) was recorded on the plants treated with DAP, followed by urea + DAP (1.01±0.65), Control (0.83±0.52), and urea (0.78±0.47). The maximum population per leaf of whitefly (3.79 ± 0.24) was recorded on the plants treated with urea + DAP, followed by urea alone (2.00 ± 0.36), DAP (1.49 ± 0.18), and control (0.08 ± 0.06). The overall mean population of whitefly (0.60 ± 0.067) was recorded on plants treated with urea + DAP, followed by urea alone (0.40 ± 0.062), DAP (0.35 ± 0.064), and Control (0.05 ± 0.052). The yield of okra crop showed that plots treated with Urea+ DAP yielded 746 kg per acre, followed by urea (670), DAP (519), and control (354). Analysis of variance showed significant difference (P < 0.05) in population of whitefly, jassid and yield of okra between treatments plots.