土壤水分对稻米外观品质的影响

水稻的分蘖期、长穗期、抽穗后1～10d、11～20d、21～30d及1～30d,用负压式土壤湿度计监测,分别进行土壤水势为-30～-35kPa、-60～-65kPa的控水处理,收获后对优势粒、中位粒、劣势粒进行粒形和垩白测定,发现在不同土壤水分下S品种长穗期和抽穗后1～10d控水显著抑制了籽粒伸长,也不同程度的抑制了籽粒增宽和长厚,以S4处理受抑制的程度最为严重;Y品种主要是长穗期控水显著抑制了粒长、粒宽和粒厚;两品种的多数处理不同程度的提高了粒厚,这在优势粒中更明显;土壤水分对粒长/宽的影响很小。S品种各处理垩白率、垩白度多低于CK,Y品种各处理垩白率、垩白度多高于CK。对两个品种来说长穗期是影响外观品质的主要水分敏感期,节水栽培应从品种选择入手。

Effect of Soil Moisture on Appearance Quality of Rice

During the periods of 1~10day, 11~20day, 21~30day and 1~30day after tillering stage, booting stage and heading stage, controlling water treatments were carried out under -30~-35Kpa and -60~-65 Kpa of soil water potential respectively by measuring of soil negative pressure tester. Grain shapes and chalkness of superior grain, middle grain and inferior grain were measured after harvest. The results showed that controlling water treatments of S variety especially treatment 4 restrained grain length, width and thickness differently during 1~10day after booting stage and heading stage; Controlling water treatments of Y variety restrained grain length, width and thickness during booting stage; More treatments of the two varieties especially of superior grain increased grain thickness differently. Soil water affected grain length/ width slightly. Chalkness and percentage of chalkness of S variety were lower than CK , that of Y variety were reverse. Appearance quality was affected mainly by booting stage for the two varieties. Saving water planning should stared with choice of varieties.