Efficiency of rice seed treatment with fungicides for controlling Helminthosporium oryzae

Abstract

In order to verify efficiency of fungicides in rice seed treatment for controlling Helminthosporium oryzae, a seed sample of rice from cultivar IAC 47 with 46% fungus infection was treated with several fungicides and tested for health by the blotter method. The following products were used: thiram 70 dust, 1750 mg a.i./kg of seeds; captan 50 WP 1500 mg; guazatine + imazalil (30 + 2) L 0.64 ml; iprodione 50 WP 1000 mg; iprodione + thiram (20 WP + 60 dust) 2000 mg; imazalil 2,5 dust 87,5 mg. Most of the fungicides significantly reduced H. oryzae seed infection. The most efficient were: guazatine + imazalil, iprodione and iprodione + thiram. A field experiment was carried out in the 1983/84 growing season of with treated seeds in randomized plots with four replications. Although differences between treatments were not significant for emergence and production, negative correlation obtained for seed infection x emergence as well as for seed infection x production, showed influence of seed treatment on these parameters.