Bacterial Blight of Cotton

Abstract

Summary 1. Bacterial blight of cotton is potentially one of the most damaging diseases of cotton. 2. Its symptoms and adverse effect on yield are described. 3. Control measures include: (i) cultural techniques of crop sanitation, and the destruction of crop residues, as well as close seasons and crop rotation; (ii) chemical seed treatments and foliar sprays; (iii) the breeding of resistant varieties. 4. Techniques are described for the breeding of resistant varieties, and sources of useful genetic plant resistance identified. 5. The complex nature of the interactions between host genetic resistance, variation in the pathogen and environment is emphasized. 6. Successful resistance‐breeding programmes in Africa and the USA are reviewed, and attention is drawn to the pressing need for resistant varieties in India and Pakistan. 7. Continued success in the control of bacterial blight will require integrated programmes that include cultural methods, the use of chemicals (particularly as seed treatments) and the cultivation of resistant varieties with durable resistance.

Diallel analysis of yield components, fibre quality and bacterial blight resistance using spaced plants of cotton

“…Reba P279 was resistant to race 18 of bacterial blight as was expected because it contains the resistance genes B 2B3B9L (Innes, 1983) . Siokra was also immune to race 18 of the pathogen and probably inherited the resistance gene combination B2B3B7 from one of its parents, cv .…”

“…The inoculum was prepared using leaves showing wet lesions from plants that had been previously infected with race 18 of the pathogen cultured in the laboratory . Race 18, currently the most virulent race in Australia, overcomes the majority, but not all, of the known major resistance gene combinations (Follin, 1983 ;Innes, 1983 ;Hussain, 1984), and is the predominant race in Australian susceptible commercial crops (S .J . Allen, personal communication) .…”

Current status of breeding cotton for resistance to bacterial blight in Zimbabwe

“…Wickens, 1953;El Nur, 1970;Ebbels, 1976), the most recent and comprehensive being that by Innes (1983).…”

Characterization of Xanthomonas citri subsp. malvacearum strains in Iran

“…The scratched leaves of two local cotton cultivars which are Varamin and Sahel were infiltrated with a suspension of selected bacterial isolates at concentration of 10 7 cfu/ml and covered with polyethylene bags for 24 h. The seedlings were further maintained in room temperature and under high moisture conditions for two weeks until the typical symptoms were observed (Innes, 1983).…”

“…malvacearum (Xcm), the causal agent of bacterial blight of cotton (Gossypium spp.) is one of the most devastating bacterial diseases which starts as angular leaf spot followed by black canker on stems and boll rot that consequences in discolored lint and infested seeds which are the main source of pathogens transmission (Innes, 1983). Report of this disease in Iran goes back to the years 1959 to 1972 in central and Southern parts of the country (Amani, 1972).…”