灌水次数和施钾量对冬小麦茎秆形态特征和抗倒性的影响

为进一步明确兼顾节水高产抗倒的最佳灌水与施钾量组合,以冬小麦品种藁优2018为材料,通过二因素随机区组试验,研究了3种灌水次数(不灌溉、灌拔节水、灌拔节水和扬花水)和4个施钾量(施K_2O0、75、150和225kg·hm~(-2))对冬小麦茎秆形态特征和抗倒性的影响。结果表明,随灌水次数和施钾量的增加,小麦株高和重心高度显著增高,茎秆基部2个节间的单位长度干重、直径、机械强度和抗倒指数显著增加。而茎秆壁仅随施钾量的增加而显著增厚。小麦产量和3个产量构成因素也随灌水次数和施钾量的增加而增加,但4个施钾量之间的千粒重差异不显著,K225与K150之间的穗数、穗粒数和籽粒产量差异不显著。茎秆抗倒指数与茎秆基部第1、2节间的单位长度干重、直径呈极显著正相关,与株高、重心高度也呈极显著正相关。综合各项指标,春季在拔节期和扬花期灌2次水,施K_2O 150kg·hm~(-2)有利于实现小麦高产和钾肥高效,且茎秆抗倒性能较好。

Effect of Irrigation Frequency and Potassium Application Amount on Stem Morphological Characteristics and Lodging Resistance of Winter Wheat

In order to further clarify the optimal combination of irrigation frequency and potassium application amount for water saving,high yield and lodging resistance of wheat,a field experiment was conducted by two-factor randomized block design,with a winter wheat cultivar Gaoyou 2018 as material. The irrigation contains no irrigation,once irrigation at jointing,and twice at jointing and anthesis. The potassium application amount contains K₂O at 0,75,150 and 225 kg·hm^-2 levels,disignated as K0,K75,K150 and K225,respectively.Stem morphological characteristics and lodging resistance of wheat were determined. The results showed that,with the increase of irrigation frequency and potassium application amount,the height and gravity center of wheat plant,and the dry weight per centimeter,diameter,mechanical strength and lodging resistant index of the 1st and 2nd basal internodes of wheat stem were all increased significantly. The wall thickness of the 1st and 2nd basal internodes was significantly increased with the increase of potassium application. The grain yield and yield components were all increased with the increase of irrigation frequency and potassium application amount,but the difference of thousand grain weight was not significant among the four potassium application levels,and the differences of spike amounts per hm,grain amounts per spike and grain yield between K225 and K150 were not significant. Stem lodging resistance index was significantly positively correlated to dry weight per centimeter and diameter of the 1st and 2nd basal internodes,and significantly positively correlated to the height and gravity center of wheat plant. It was concluded that the combination of twice spring irrigation at jointing and anthesis,and K₂O application of 150 kg·hm^-2 was beneficial to achieve high yield and high use efficiency of potassium fertilization,which also improved lodging resistance of wheat stems.