农田黑土中不同浓度乙草胺对玉米苗期生长的影响

Effect of Different Concentration of Acetochlor on the Maize Seedling Growth in the Agricultural Mollisol

通过黑土盆栽试验研究了施用化肥条件下不同浓度乙草胺对玉米苗期生长的影响。结果表明,虽然在整个取样期间,植株体内无乙草胺残留检出,但是乙草胺施用对玉米苗期的形态和生理指标均具有一定影响。植株中超氧化物歧化酶活性、地下部分过氧化物酶活性和株高、根长等形态指标在玉米生长前期发生明显变化,其变化趋势受到乙草胺施用量的显著影响。在施有等量化肥的条件下,低浓度和高浓度乙草胺的施用抑制了玉米的生长,但中等浓度乙草胺对苗期玉米的生长表现出一定的促进作用。随着种植时间的延长,乙草胺活性降低,植物体的各项抗性指标和生理指标趋于一致。

The effect of different concentration o f acetochlor {N- （2-ethyl-6-methylphenyl）-N-（ethoxymethyl）- chloroacetamide} on the maize （Zea mays L.） seedling growth under fertilization in Mollisol was investigated through the pot experiment. The results showed that the application of acetochlor influenced both the morphological and the physiological index to some extent although the residue of acetochlor was not detected in the maize tissues. The superoxide dismutase （SOD） activity in all tissues, the peroxidase （POD） activity in the underground part, and the height, the fresh weight and the root length, changed significantly on the early stage of seedling growth with the similar tendency after acetochlor application. When NPK fertilization was kept the same, the change tendency of the index and the enzyme activity was relied on the concentration of acetochlor. The seeding growth was inhibited on both the lower and the higher concentration while the medium concentration of acetochlor was somewhat profitable to the growth of maize seedling. With the cultivation processed, the bioavailability of acetochlor decreased and thus the resistance of the crop reconverted to normal status and each indicator tended to be consistent.