ABSTRACT
Laboratory, greenhouse and field experiments were carried out with maize seeds from the hybrids Z 8392 and DAS 9560, in 2000/2001 and 2001/2002, in order to evaluate effectiveness of 10 products, in seed treatment, to control seed and soil-borne fungi. The following products at the indicated doses/100 kg of seeds were evaluated: propamocarb 722 SA PM (1,000 mL), captan 750 TS (160 g), carbendazin + thiram (150 + 350) SC (200 mL), fludioxonil + metalaxyl – M (25 + 10) SC (150 mL), carboxin + thiram 200 SC (250 e 300 mL), thiram + thiabendazole (350 + 85) SC (200 mL), tolylfluanid 500 PM (150 g), fipronil 250 FS (150 mL), carbendazin + thiram (150 + 350) SC + fipronil 250 FS (100 + 100) mL and thiram 500 SC (300 mL). After treatment, health conditions of seeds were evaluated in laboratory experiments, by the blotter method; emergence and seedling symptoms were registered in greenhouse experiments in seedbed boxes containing soil; in the first year, of three experiments performed in greenhouse, one was carried out in sterilized soil and two in Pythium sp. naturally-infested soil, in two different weather conditions; in the second year only sterilized soil was used. Two field experiments were carried out: one in 2000/2001 in which emergence of treated seeds was registered and another one in 2001/2002 for evaluating emergence and yield. Statistical analysis showed positive effects of seed treatment on parameters studied for most of the products evaluated. In 2000/01 the following products were effective for maize seed treatment in the following decreasing order: captan; tolylfluanid and fludioxonil + metalaxyl M; carbendazin + thiram; carboxin + thiram and thiram + thiabendazole. In 2001/2002 the effectiveness order was: tolylfluanid; captan; fludioxonil + metalaxyl M, carbendazin + thiram and (carbendazin + thiram) + fipronil; carboxin + thiram (250 and 300 mL) and thiram. Pythium sp. was controlled by captan, fludioxonil + metalaxyl – M, carboxin + thiram (300 mL), thiram + thiabendazole and tolylfluanid, with the best results for captan and fludioxonil + metalaxyl – M.
KEY WORDS
Seeds; chemical control; fungicides;
Zea mays