An integrated approach to the control of purple blotch of onion seed-crop.

Abstract

Onion (Allium cepa L.) is an important and widely used spice of Bangladesh. It is also used as vegetable all over the world. In Bangladesh, the greater districts of Faridpur, Pabna, Rajshahi, Dinajpur, Jessore, Dhaka and Camilla are the major onion growing areas. Its present production is around 1,48,000 mt against the requirement of one million ton estimated on a modest requirement of 25 g/capita/day (Hossain and Islam, 1993). The local cultivars namely, Taherpuri, Jhitka, Salta, Kalasnagari and Faridpur bhati are mainly grown in the country (Rahim and Siddique, 1991 ). The crop suffers from many diseases (Meah and Khan, 1987; Ahmed and Hossain, 1985; Munoz et al., 1984). Among them purple blotch caused by Alternaria porri (Ellis) Cif. is noted as the major disease in many onion growing countries including Bangladesh (CastellanosLinares et al., 1988; Rahman et al., 1988; Meah and Khan, 1987; Bose and Som, 1986; Ahmed and Hossain, 1985; Munoz et al., 1984; Ashrafuzzaman, 1977). Ahmed and Goyal (1988) mentioned that purple blotch, incited by A. porri, is a major problem of onion (Allium cepa) in India.