亏缺灌溉对马铃薯生长产量及水分利用的影响

Effects of deficit irrigation on growth, yield and water use of potato plants

为了解析马铃薯不同品种对水分亏缺的响应,探讨不同品种对水分需求量的差异,该研究在大田遮雨棚滴灌下,以马铃薯品种‘青薯9号’和‘大西洋’为材料,参考西北区和本试验区的年平均降雨量,设置5个水分处理,将参考试验区年平均降雨量的值划分为正常灌水(A),逐级调亏灌水量的值划分为轻度(B)、中度(C)、重度(D)和特重度(E)亏缺灌水处理,研究灌水量对不同品种马铃薯植株生长(株高、茎粗、叶面积)、生物量与分配、叶片相对含水量、产量与构成因素、水分利用的影响。结果表明:正常灌水下,‘青薯9号’株高增长速度大于‘大西洋’,且测定期内持续增高,但‘大西洋’叶面积快速扩增期的扩增速度大于‘青薯9号’;2个品种各器官干质量变化趋势不一致,‘大西洋’各器官干质量呈增长趋势,‘青薯9号’茎叶和根干质量呈前期增长后期下降、块茎干质量呈显著增加趋势(P<0.05),且‘青薯9号’块茎生物量分配比例最高值为57.96%,仅是‘大西洋’最高值的67.43%;2个品种叶片相对含水量均呈先升高后降低的变化趋势;‘大西洋’单株结薯数、单株产量、公顷产量、商品薯率高于或显著高于亏缺灌溉(P<0.05),‘青薯9号’仅商品薯率和大薯率高于或显著高于亏缺灌溉(P<0.05),其他指标则显著低于轻度亏缺灌溉(P<0.05),水分利用效率和灌水效率分别为152.62kg/(hm^2·mm)和130.70%。亏缺灌溉下,随水分亏缺度加重,‘大西洋’株高、茎粗和叶面积扩增的抑制大于‘青薯9号’,2个品种叶片相对含水量降低、生物量积累的增速和绝对值降低、产量和大薯率显著下降(P<0.05),且‘青薯9号’上述指标的降幅小于‘大西洋’,其中轻度亏缺灌溉下,‘青薯9号’单株结薯数和公顷产量具有补偿效应,较正常灌水分别增加22.79%和11.71%,水分利用效率提高41.48%、灌水效率提高60.05%,抗旱系数为1.12。因此,‘青薯9号’轻度亏缺灌溉,可控制其地上部旺盛生长,利于块茎形成和膨大,‘大西洋’应保证充足水分供给,不宜亏缺灌溉。

In order to analyze the response of potato varities to water decifit and investigate the differences of potato varities in water demand,the potato varieties ‘Qingshu 9’ and ‘Atlantic’ were treated under five water treatments by referring to the annual average rainfall in the northwest and the experimental area, which was normal irrigation (A) according to the annual average rainfall in the experimental area, and mild (B), moderate (C), severe (D) and extremely severe (E) by level-adjusting deficit irrigation to study the effects of irrigation amounts on plant growth (plant height, stem diameter, leaf area), biomass and its distribution in organs, leaf relative water content, yield and its component, and water use under drip irrigation condition with rainproof shelter in field. The results showed that compared with deficit irrigation, plant height growth rate and leaf area expansion rate of the two varieties under normal irrigation condition were faster . The growth rate of ‘Qingshu 9’ was higher than that of ‘Atlantic’, and it continued to increase during measuring period , whereas the leaf area of 'Atlantic' is 1.72 times larger than that of ‘Qingshu 9’ on the 71st day after sowing, so its single leaf area is larger than ‘Qingshu 9’. During the measured period, the changing trends of organ dry matter of two varieties were not consistent under normal irrigation, the dry matter of all organs of 'Atlantic' increased, whereas the dry matter of stems, leaves and root of ‘Qingshu 9’ increased in the early period and decreased in the late period, the tuber dry matter increased significantly (P<0.05), the distribution ratio of tuber biomass of ‘Qingshu 9’ was 57.96%, of which, the 'Atlantic' was 85.96% on the 120th day after sowing, indicated that there was still dry matter maintained in stems and leaves rather than in tubers of ‘Qingshu 9’ at this period, which implies its maturity was later than ‘Atlantic’. The trend of leaf relative water content of two varieties was increased and then decreased under normal irrigation. The number of tuber and yield per plant, yield per hectare, the rate of large tuber of ‘Atlantic’ were significantly higher (P<0.05) under normal irrigation compared with deficit irrigation, while the large tuber rate of ‘Qingshu 9’ were significantly higher (P<0.05), and the number of tuber and yield per plant, yield per hectare were significantly lower (P<0.05) under normal irrigation compared with mild irrigation, the yield is 92.49% higher than that of 'Atlantic', its water use efficiency (WUE) and irrigation efficiency (IE) are 152.62 kg/(hm^2·mm) and 130.70% respectively. With the increase of water deficit, the inhibition of plant height, stem diameter and leaf area expansion of ‘Atlantic’ was greater than that of ‘Qingshu 9’, decrease of leaf relative water content of ‘Qingshu 9’ was less than that of ‘Atlantic’. The accumulation rate and absolute value of biomass of two varieties were reduced, resulting in the yield and large tuber rate were significantly decreased (P<0.05), of which the decreasing range of ‘Qingshu 9’ was smaller than that of ‘Atlantic’, under extremely severe deficit irrigation, the dry matter of 'Atlantic' at the 120th day after sowing was even lower than that at the 87th day after sowing. Under mild deficit irrigation, the number of tuber per plant and yield per hectare of ‘Qingshu 9’ showed compensatory effect, which were 22.79% and 11.71% higher than that under normal irrigation, WUE increased 41.48%, IE increased 60.05% and drought coefficient is 1.12. The results showed that ‘Qingshu 9’ is more resistant to drought than ‘Atlantic’, the exuberant aboveground growth of ‘Qingshu 9’ can be inhibited under mild deficit irrigation, which is conducive to tuber formation and expansion, on the contrary,‘Atlantic’ should by supplied with sufficient water during the growth period.