土壤干旱对甘薯生育及产量的影响

利用甘薯品种郑红５号和徐薯１８研究了土壤干旱对甘薯生育和产量的影响。结果表明，生长前期（栽后０～６０天）叶片数、叶面积、茎长及其相应的干旱胁迫指数均随土壤干旱程度的加重而相应减少，薯块的形成和膨大也受到严重影响。当土壤含水率在６％～１０％范围内，６～８月各月份进行的干旱处理与对照（全期湿润）相比，其鲜薯产量差异均达极显著水平。干旱指数为６月＞７月＞８月＞９月。前期干旱比后期干旱对鲜薯产量影响较重。据此，提出了甘薯旱地栽培应充分利用自然降水及水浇地栽培经济用水的技术措施。

Influence of Soil Aridity on the Growth, Development and Yield of Sweet Potato (Ipomea batatas L.)

The influence of different degree of soil aridity upon 2 sweet potatoes, Zhenghong 5 and Xushu 18, has been studied. The results showed that in the earlier stage of growth (0-60 days after planting), the number of leaves, leaf area, length of stem and their relative dry stress indices decreased as the degree of soil aridity increased. And the formation and swelling of tuber was also affected seriously. From June to August, when the soil moisture content ranged 6-10% the yield of tuber was significantly influenced in all treatments in comparing with the control keeping moist in the whole growth period. The yield was damaged more seriously by the drought in earlier stage than in the later stage: June>July>August>September. According to this study, some techniques were suggested to utilize sufficiently the rainfall and to irrigate the field economically.