In order to evaluate the effects of cutting timing on the accumulated temperature requirement and yield and quality of winter wheat, six cutting time treatments were conducted on winter wheat (Triticum aestivum) at stages of tillering,elongation and booting in a rain-fed region of the Loess Plateau. (1)When the wheat was cut before mid-tillering (6 tillers), no significant difference was found in the accumulated temperature requirement of crucial growth stage,about 0. 9 -1. 5 t/hm2 dry matter could be harvested for forage and the yield and quality both of regrowed grain and stubble was not significantly affected compared to uncut control; as to the wheat cut after late tillering stage (9 tillers), the accumulated temperature requirement between elongation and flowering and ripening was greatly decreased, though there was 60% more forage available than that of crops cut before mid-tillering, both the grain and stubble yield was significantly reduced compared with uncut contral. (2)Path analysis for grain yield showed that reduction of grain yield of cut crops was due to the lower plant height and reduced spike number per unit. In a word,the most appropriate time to cut winter wheat for dual-purpose should be prior to the mid-tillering stage (6 tillers) ,ensuring the regular accumulated temperature require of crucial growth stage and the conformation' stability of grain yield and quality.%对黄土高原塬区冬小麦‘陇育216’于分蘖期、拔节期及孕穗期进行刈割处理,以不刈割为对照,测定冬小麦再生生长发育的积温需求及籽粒产量及其品质,探究刈割利用时间对冬小麦再生生长积温需求及产量构成的影响.结果表明:(1)分蘖中期(6个分蘖)前刈割利用,小麦再生各阶段的有效积温需求较对照无显著差异,在收获小麦青干草0.9～1.5 t/hm2的同时,能保证籽粒、秸秆产量及其品质较对照均无显著下降；分蘖期后期(9个分蘖)及其后刈割利用,拔节至开花及成熟期的有效积温需求显著减少,尽管较分蘖期可多收获60％的青干草,但籽粒、秸秆产量较对照均显著降低.(2)通径分析发现,刈割主要通过降低再生植株高度及减少单位面积穗数而导致冬小麦籽粒减产.研究表明,为维持冬小麦再生生长节律、籽粒产量及品质形成的稳定,冬小麦刈割利用的时期应不迟于分蘖中期(6个分蘖).
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