EFFECT OF DIFFERENT LEVELS OF BLACK POINTED SEED ON HEALTHY WHEAT SEED PRODUCTION

Abstract

Effects of different levels of black pointed seed on healthy wheat seed production were studied in the field and laboratory during 2006-2007. The treatments considered the levels of black pointed seed were Ty = Best seed treated with Vitavax-200 @ 0.25% of seed weight, T; = Seed sample containing 5% of black pointed seed, T, = Seed sample containing 7% of black pointed seed, T; = Seed sample containing 12% of black pointed seed, T, = Seed sample containing 18% of black pointed seed, T; = Seed sample containing 25% of black pointed seed and T, = Seed sample containing 35% of black pointed seed. The maximum (246.64 — 268.68) emergence of seedlings / m’ was recorded in To and the minimum (182.58 — 190.75) was in T¢ after 7 and 15 days of sowing indicating general tendency of decreasing seedlings emergence with the maximum use of black pointed seed. Percent leaf area infection (%LAI) of flag leaf and flag leaf-1 were increased with increasing the age of plant. The maximum and minimum Area Under Disease Progress Curve (AUDPC) of flag leaf and flag leaf-1 were recorded in Ts and T3, To, respectively. Maximum number of total seeds (35.05), apparently healthy seeds (34.15) and the best seed (31.37) per spike observed when the disease free best seed were sown in field. Number of black pointed seed (3.74) and under sized seed (4.89) per spike were maximum in treatment T,. Highest seed yield (4.02 t/ha) and 1000 grain weight (46.38 g) obtain from the treatment Tp and lowest (3.11 t/ha, 43.97 g) in Ts. Fungi associated with harvested seed and their prevalence were Bipolaris sorokiniana (6.5 - 80.0%), Alternaria spp. (1.5 - 31.0%), Fusarium spp.(3.25 - 29.0%), Curvularia spp. (2.25 - 27.0%), Aspergillus spp.(3.0 - 24.0%) and Epicocum spp. (1.75 - 30.0%) respectively.