UTILIZATION OF FERTILIZERS APPLICATION METHODS FOR THE MANAGEMENT OF Tetranychus urticae POPULATION IN BRINJAL CROP.

Spotted spider mites (Tetranychus urticae) are serious pest of many crops including brinjal. Brinjal crop suffers defoliation and fruit drop due to severe attack of Tetranychus urticae about twice or thrice in a single growing season. Fertilizer management was suggested as an effective alternative to acaricides in different integrated pest management programs. This study was planned to investigate the potential of two different fertilizers (sulphur & nitrogen) with two different modes of applications (Foliar spray & basal fertigation) along with two controls (standard fertilizer & zero fertilizer). The field trials were conducted at two different locations (NARC, Islamabad & URF, Koont) and two cropping seasons (2019 & 2020). Total three brinjal cultivars were used as major plot and all six treatment were applied in RCBD design in these plots. Chlorophyll a, b and total content were recorded before and after treatments. Laboratory test were conducted for total carbohydrates (%) and crude protein content (%). Mites population recorded before and after the treatments was corelated with these factors. Mean yield from four post treatment observation was also recoded. Generated data has revealed that sulphur has acaricidal affect (40% corrected mortality) which applied through foliar spray and relatively resistant cultivar (Shamli) has height response. Population increase was maximum in basal application of nitrogen plots while maximum per unit yield was observed in T4(foliar application of sulphur) i.e. 3.38kg/10 plants at URF, Koont and 3.9 kg/10 plants at NARC, Islamabad. Acaricidal effect of sulphur was onto up to 7 days after treatment and then increase in population was started. These finding are providing a sign to move for environmentally safe management of Tetranychus urticae in brinjal crop by modifying pest behavior and utilization of its acaricidal ability. Understanding the role of fertilizer response to mite’s population will also provide a better fertilizer management tool to achieve maximum economic returns in pesticide free brinjal production. [ABSTRACT FROM AUTHOR]