苗期水分亏缺对马铃薯产量形成的影响

Effects of Water Deficiency at Seedling Stage on Potato Yield Formation

以‘费乌瑞它’和‘克新1号’为试验材料,通过在马铃薯苗期设置重度水分亏缺(最大田间持水量的35%)、轻度水分亏缺(最大田间持水量的50%)和充分灌溉(最大田间持水量的65%)3个水分处理,其他时期均充分灌溉,研究了马铃薯苗期不同水分亏缺对产量形成的影响。结果表明,2品种生育前期的叶面积指数、干物质积累量随苗期水分亏缺程度的增加而逐渐降低,而复水后,从出苗后22 d至收获的叶面积指数与干物质积累一直表现为:轻度水分亏缺>充分灌溉>重度水分亏缺,意味着一定程度的水分亏缺后,马铃薯存在明显的复水补偿效应。收获时2品种的块茎产量依次为:轻度水分亏缺>充分灌溉>重度水分亏缺,其中,轻度水分亏缺处理的商品率均高于其他2个处理,而单株结薯数表现为:充分灌溉>轻度水分亏缺>重度水分亏缺,说明适度的水分亏缺通过控制结薯数与增加块茎重量产生增产效应。

By using cvs ＇Favorita＇ and ＇Kexin 1＇ as materials, the effects of water deficit at seedling stage on potato yield formation was investigated. Three different water treatments were set up at the seedling stage, which were severe water deficit （35% of the maximum field capacity）, moderate water deficit （50% of the maximum field capacity） and full irrigation （65% of the maximum field capacity）, but at other growth period of potatoes, full irrigation was maintained for all the treatments. The results showed that the leaf area index and dry matter accumulation during early developmental stage of potatoes were decreased significantly with seedling water deficit. However, after rehydration, the leaf area index and dry matter accumulation exhibited the following trend： moderate water deficit （50%） 〉 full irrigation （65%） 〉 severe water deficit （35%）, wh ich maintained from the twenty two days after emergence to harvest. It means that potato has the compensating effect at the later developmental stage while experienced water deficit at the seedling stage and rehydrated later on. The tuber yield for the two cultivars at harvest was in order as： moderate water deficit 〉 full irrigation 〉 severe water deficit. The marketable tuber percentage under seedling moderate water deficit was significantly higher than other two treatments. However, the tuber number per plant manifested as： full irrigation 〉 moderate water deficit 〉 severe water deficit. It demonstrates that the effect of yield promotion under seedling moderate water deficit was attributed to the increase in tuber weight instead of tuber number.