杂草防控模式对木薯种质圃生境及其种质保护的影响OA

To elucidate the role of weed control in the habitat and germplasm conservation of a cassava germplasm nursery,this study used cassava germplasm from Guangxi as materials.3 treatments were established:chemical control(Che-t),physical control(Phy-t),and untreated control(Con-t).Over three consecutive years,cassava physiological indices,agronomic traits,habitat temperature and humidity,soil physicochemical properties,and mite damage index were measured,followed by multivariate correlation analysis.The results showed that physical control significantly increased the net photosynthetic rate(Pn),stomatal conductance(Cs),and intercellular CO₂ concentration(Ci)of cassava leaves,with increases of 46.11%,56.74%,and 10.00%,respectively,compared to the untreated control,outperforming chemical control.Under physical control,plant height(Ph),stem diameter(Sd),crown width(Cr),and fresh tuber weight(Ye)were markedly increased compared to the untreated control,with Ye increasing by 6.48%.Both types of control measures increased the field temperature(At),but the untreated soil had a higher moisture content(Swc)and organic matter content(Somc),which were 10.19 and 3.75 percentage points higher than those of the chemical control group,respectively.Mite damage monitoring indicated that the mite damage index(Ⅰ)in the untreated group was significantly lower than that in the treated groups,while the habitat insect population(Bn)was higher;mite damage was very significantly negatively correlated with Bn(P<0.01).Correlation analysis revealed that Pn was significantly positively correlated with Sd and Ye(P<0.05),and soil water content was very significantly positively correlated with organic matter content and insect population(P<0.01).Weed control should balance effectiveness and ecological stability;physical control is more conducive to cassava growth and yield improvement,while moderate weed retention can enhance biodiversity and reduce mite damage risk.This study provides a basis for green weed control and in situ conservation of germplasm resources in cassava nurseries.