Effect of foliar spray with Eucalyptus extracts on disease incidence and yield loss to spot blotch in Wheat Bhakkar 2001 under greenhouse condition

The efficacy of foliar spray with different treatments of flowering buds extracts of Eucalyptus camaldulensis L. and Eucalyptus torelliana F. Muell on the yield performance of wheat (Bhakkar 2001) artificially infected by Bipolaris sorokiniana was evaluated in green house. The foliar aerosol of crude extract at 1, 5 and 10% concentrations were applied under 3 spray schedules. Untreated (Healthy) and unsprayed (Diseased) controls were also managed. The effect of treatments with different spray schedules was highly significant (P < 0.05) for both of physiological and yield parameters such as plant height, leaves length/width, grain yield/spike and 1000 grain weight. Weight of 1000-grain decreased with increasing level of disease severity. Maximum decrease in number of grains/spike (16–20) was recorded in unsprayed control. In case of number of grains/spike, for each unit increase in disease severity, 0.395 units decrease in number of grains/spike were observed. The R2 (0.473) value indicates that 47.3% variations in grains yield/spike were caused by disease severity. Among the different spray schedules, spray I schedule with a 10 days gape spraying at 15, 25, 35, 45 and 55 days after inoculation appeared to be most effective, which was statistically similar to spray II schedule with a 15 days gape spraying at 15, 30, 45 and 60 DAI in reducing black point incidence and increasing grain yield. From economic point of view spray II schedule that containing four spray applications was found best followed by Spray III schedule that containing only three spray applications applied at 15, 35 and 55 DAI.