Effect of Age of Cotton Seedlings on their Susceptibility to Rhizoctonia Damping-off

Abstract

DAMPING-OFF fungi are known to destroy seedling plants during the first four–six weeks after germination. Tint¹, in his studies on Fusarium damping-off of conifers, reported a direct correlation between resistance to invasion and increasing age of host. Matus² found that cotton plants were invaded by Corticium vagum throughout the growing period, although susceptibility appeared to decline as the plant grew older. Linnasalmi³ also reported that attack by Rhizoctonia solani on cabbage, cucumber and tomato was most severe at the pre-emergence phase. Koba⁴ stated that cotton seedlings proved very susceptible to damping-off caused by Fusarium spp. at the eight- to fifteen-day old stage when stored food is exhausted and photosynthesis is low.