灌溉模式对不同群体小麦茎秆特征和倒伏指数的影响

Effect of Irrigation Schedules on Stem Traits and Lodging Index of in Winter Wheat

为明确灌溉模式对不同群体小麦茎秆倒伏的调控机制,在大田条件下设置了不灌水(W0)、灌1水(W1j,拔节期灌水;W1b,孕穗期灌水)、灌2水(W2,拔节和孕穗期灌水)、灌3水(W3,拔节、孕穗和灌浆期灌水)5种灌溉模式和基本苗180株/m2(D1)、300株/m2(D2)和450株/m2(D3)3种密度,研究了灌溉对不同群体小麦茎秆特征和抗倒伏能力的影响。结果表明:灌溉显著影响了小麦的茎秆特征和倒伏指数。随着灌溉次数的增多,株高、重心高度和产量均呈低-高-低的变化趋势;单位茎秆与基部节间干质量及干物质输出量、茎秆粗度及机械强度均随灌溉次数增多显著降低或变细。5种灌溉模式中,株高、茎粗、成熟期茎秆机械强度与单位茎秆干质量、基部一二节间单位干质量及产量均以W2较高。随密度增加,株高和重心高度显著增高;茎粗、机械强度、单位茎秆与基部节间干质量显著减小或降低;产量高低以D2>D3>D1。综合各项指标,春季灌拔节和孕穗2水,并采取300株/m2基本苗密度更有助于改善小麦的茎秆质量和产量。

In order to clarify the regulation mechanism of stem lodging under different densities and irrigation schedules,an experiment was conducted in field.The experiment included 5 irrigation schedules such as no irrigation（W0）,irrigation once at jointing（W1j） or at booting（W1b）,irrigation twice at jointing and booting（W2）,and irrigation three times at jointing,booting and grain-filling（W3）,and 3 planting densities such as 180（D1）,300（D2） and 450 seedlings per square meter（D3）.The results indicated that irrigation had a significant effect on stem traits and lodging index.Plant height,stem gravity height and grain yield presented a low-high-low variation trend with the increasing of irrigation times.Dry weight of stem and basal internodes per centimeter,dry matter output of stem and basal intermodes per centimeter,stem diameter and stem mechanical strength decreased significantly with the increasing of irrigation times.Stem indexes of W2 such as plant height,stem diameter,stem mechanical strength,dry weight of stem and basal internodes per centimeter and grain yield were superior to other irrigation schedules.At the same time,plant height and associated gravity height became increased significantly.With the increasing of densities.Stem diameter,stem mechanical strength,dry weight of stem and basal internodes per centimeter,dry matter output of stem and basal internodes per cetimeter decreased significantly with the increasing of densities.And grain yield of D2 was higher,followed by D3 and D1.It indicated that spring irrigations applied at jointing and booting stage（W2）,and combining with 300 seedlings per square meter could improve stem quality,lodging resistance and grain yield effectively.