Dates of sowing; and varieties for the management of Alternaria blight of linseed (Linum usitatissimum L.)

Field experiments conducted during 2006-07 and 2007-08 for the management of Alternaria blight of linseed (Linum usitatissimum L) caused by Alternaria lint Dey and A. linicola Groves and Skolko, showed that 15th October sown crop had highest disease intensity followed by gradual decline in later sown crops. Highest seed yield of 977.78 and 790.00 kg/ha were obtained in 05 November sown crop followed by 15 November (877.3 and 658.33 kg/ha) which was also at par with 15 and 25 October sown crops. Lowest yield of 606.67 kg/ha and 406.66 kg/ha was recorded in 05 December sown crop during both the years, respectively. Based on the disease severity, observations recorded during both the years (2007-08 and 2008-09), variety Jeevan, Gaurav and K-2 were found resistant and Sweta as moderately resistant. On mean basis Gaurav showed least susceptibility (16.97%) and Sikha was most susceptible (33.56%). Lowest mean bud damage was also recorded in Gaurav (9.24%) followed by Sweta (9.55%) and K-2 (10.12%), respectively. Moderately resistant cultivar Sweta yielded highest (1466.66 kg/ha) followed by Sikha (1312.50 kg/ha) and K-2 (1287.50 kg/ha) on mean basis. Out of 200 genotypes, ten viz; Polf-12, Polf-13, Polf-15, Polf-16, Polf-19, Polf-22, Polf-23, Polf-29, Polf-39 and RL-15-1 were found resistant and 15 as moderately resistant.