EFFECTS OF FUNGICIDES USED BEFORE PLANTATIONS ON YIELDS AND DISEASES OF RICE IN SOUTH EASTERN NIGERIA

Brown leaf spots disease caused by Drechslera oryzae and kernel discoloration disease caused by Curvularia lunata are major constraints in rice production in Nigeria. The effects of preplanting fungicides and rice varieties on these diseases were therefore investigated. The study was carried out in a randomized complete block design experiment. Three rice varieties: BG 90-2. ITA 306, and IR 1416 were before planting treated with Thiram, Benlate, Dithane M.45, Chinoin Fundozol and Agrocit at the recommended rates of 30 gm/100 kg seed; 2 gm/kg seed; 3 gm/kg seed; 2 gm/kg Seed and 2 gm/kg Seed respectively. Data on disease severities showed that rice seeds treated with these fungicides produced leaves with significantly (P<0.05) lower brown leaf spots than the control. The same was also true in the case of kernel discoloration. While there was no significant (P > 0.05) difference in varietal response to brown leaf spots disease, the rice variety BG 90-2 produced seeds with significantly (P < 0.05) higher kernel discoloration than ITA 306. Treatment of IR 1416 and BG 90-2 rice seeds with Thiram produced highest mean number 21.10 and 22.45 respectively) of panicles per stand. This contrasted with the minimum mean number (11.20) of panicles per stand obtained when ITA 306 seeds were treated with the same Thiram. Although rice seeds treated with Agrocit yielded higher paddy (2.07 tons/ha) than all other seeds treated with the other fungicides, the highest paddy quality (i.e. 1000 seed weight) of 24.88 gm/plant was however obtained from rice seeds treated with Dithane M-45.