Management of Fusarium wilt under sick field
Field experiments were conducted during cropping season
of 2010 and 2011 at Wabagai, Thoubal district, Manipur
(Latitude 240N, longitude 930E and altitude 2539 ft above
sea level). The experiment was laid out in RBD with three
replication. The plot size was kept 2×2 m2 with 55×20cm plant
spacing under irrigated condition. The plots except
uninoculated control were made sick by adding sand maize
meal growth culture of F. oxysporum f.sp. lycopersici before
planting @ 100g/plot. Planting of susceptible local tomato
variety ‘Manikhamnu’ was done in the first week of March in
both the years. Disease severity was monitered at 2-day
intervals for 25 days after planting, and was scored based
on a symptom severity scale, according to Alabouvette (1986)
where 0 = asymptomatic plants, 1 = weakly infected plants
(≤ 50% of leaves chlorotic or wilted), 2 = highly infected plants
(>50% of leaves wilted but plants not dead), and 3 = dead
plants. Disease incidence was determined using the formula:
Disease incidence (%) = [(Σscale × No. of plants) / (highest
scale × total No.of plants)] × 100