Studies on bacterial spot of bell pepper caused by Xanthomonas campestris pv. vesicatoria
2011
Gupta, S.K. | Prashad, Durga
Bell pepper (Capsicum annuum L.) is an important vegetable cash crop of mid hills of Himachal Pradesh. During cultivation the crop is severely attacked by bacterial spot (Xanthomonas campestris pv. vesicatoria (Doidge) dye) disease which causes significant yield losses. Keeping in view the importance of the disease and crop, present investigations were undertaken to study the role of environmental factors on disease development and to devise suitable disease management strategies comprising of host resistance, bioagents, plant origin pesticides and chemicals. Disease appeared in the second week of July in both the cropping seasons (2008 and 2009) after the commencement of rains, indicating conducive influence of rainfall and high relative humidity on the disease. Moderate temperatures of 25 + 1ᵒ C coupled with high related humidity (80%) favoured the disease development. Two lines viz., Feroz and EC-57997 were found moderately resistant while eight lines viz. selection 17-1-2, Kanauri, SP-628, Midway, EC-57996, Navgaon Collection, Nishant KTCPH-7 exhibited moderately susceptible reaction under natural epiphytotic conditions. Among five biocontrol agents evaluated, only Pseudomonas fluorescens inhibited the growth of bacterium under in vitro conditions. Aqueous abstract of Allium sativum and Curcuma longa inhibited the growth of the bacterium under in vitro conditions. Foliar sprays of streptomycin sulphate (0.01%) + Copper oxychaloride (0.25%) and streptomycin sulphate (0.01%) alone resulted in minimum disease severity and maximum fruit yield.
显示更多 [+] 显示较少 [-]