Seletividade de nicosulfuron isolado e em mistura com atrazine para trinta híbridos comerciais de milho

Abstract

Estudou-se a seletividade do herbicida nicosulfuron, isolado e em mistura com atrazine, a trinta híbridos comerciais de milho, no ano agrícola 2006/2007, em área da UNESP, Campus de Jaboticabal (SP). O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema fatorial 5 x 30. Foram avaliados cinco herbicidas: nicosulfuron isolado (0, 50 e 60 g ha-1) e em mistura com atrazine (20 g ha-1 + 1,5 kg ha-1; 40 g ha-1 + 3,0 kg ha-1). O nicosulfuron isolado e em mistura com atrazine foi seletivo a 23 híbridos (A015, AG 2040, AG 8060, AGN 30A06, BM 1115, BRS 1035, BX 974, CDXS 012, CDXT 295, MAXIMUS, NB 3234, NB 4214, NB 8304, P 30K 73, P 30F36, P32R48, P30S40, SHS 5080, SHS 7070, SHS 7080, XB 6010, XB 6012, XB 7116), com base na produtividade de grãos. Dentre os trinta híbridos estudados, doze apresentaram efeito significativo de fitointoxicação, sendo eles: AG 2040, AG 8060, AGN 30A06, CDXS012, CDXT 295, NB 3234, NB 7324, SHS 5090, SHS 7070, XB 6010, XB 6012, XB 7116. A injúria visual causados pela aplicação de 50 e 60 g ha-1 nicosulfuron foi mais pronunciada do que as doses em mistura com atrazine. Os híbridos que sofreram perda na produção de grãos pela aplicação de nicosulfuron, isolado ou em mistura com atrazine, foram AGN 30A05, BRS 1015, BRS 1031, BX 981, NB7324, SHS 5090, P 30R32.

Aiming selectivity studying the nicosulfuron herbicide, isolated and in mixture with atrazine, on thirty corn hybrids, in the agricultural year of 2006/2007, at UNESP, Campus of Jaboticabal, (São Paulo State). The experimental design was completely randomized blocks, four replications, in a factorial scheme 5 x 30. Five herbicides treatments were evaluated; isolated nicosulfuron (0, 50 and 60 g ha-1) and in mixture with atrazine (20 g ha-1 + 1.5 kg ha-1 and 40 g ha-1 + 3.0 kg ha-1). Nicosulfuron isolated and in mixtures with atrazine was selectivy to 23 hybrids (A015, AG 2040, AG 8060, AGN 30A06, BM 1115, BRS 1035, BX 974, CDXS 012, CDXT 295, MAXIMUS, NB 3234, NB 4214, NB 8304, P 30K 73, P 30F36, P32R48, P30S40, SHS 5080, SHS 7070, SHS 7080, XB 6010, XB 6012, XB 7116) based in grain yield. Among thirty hybrids studied, only twelve hybrids show significant effect of phytotoxicity, which were: AG 2040, AG 8060, AGN 30A06, CDXS012, CDXT 295, NB 3234, NB 7324, SHS 5090, SHS 7070, XB 6010, XB 6012, XB 7116. The visual damage caused by the application of 50 e 60 g ha-1 nicosulfuron were more pronounced than the nicosulfuron doses in combination with atrazine. The hybrids that suffered losses in its production by the application of nicosulfuron alone or in combination with atrazine were hybrids AGN 30A05, BRS 1015, BRS 1031, BX 981, NB7324, SHS 5090 and P30R32.