Temperature linked degenerative tissue rots inCapsicum annuum(L.) varieties diseased withPhytophthora capsici

Abstract

Five-week-old seedlings of Capsicum annuum variety SAMPEP 4, Californian Wonder and Ex Dandamasa drenched with 15,000 infectious units per ml of Phytophthora capsici were incubated at 58C, 208C, 308C and 358C in alternating light-dark cool cycle Gallenkamp incubators and monitored for root rot development. Each host-pathogen system was replicated five times. Successful disease development was contingent on been incubated at ambient temperature for not less than 3.5 + 0.5 h. Depending on variety, degenerate tissue rots were aggravated 2-3 days after a preconditioning temperature treatment for 24 h possibly linked to cell wall constitution, composition and permeability. Lesion development on stem heightened (27.8%) when incubated at temperatures above 208C. Ten days after treatment, plant mortality and disease severity were not affected significantly by post-inoculation temperature.