行距配置和化控对冬小麦茎秆质量和抗倒性能的影响

为明确行距配置和多效唑化控对小麦茎秆质量和抗倒性能的影响规律,采用裂区试验,研究了行距配置(12 cm等行距、15 cm等行距、12.5 cm+12.5 cm+20 cm共3个水平)和多效唑化控(对照、起身期化控、拔节期化控3个水平)对冬小麦茎秆形态的影响.结果表明,株高、茎秆重心高度和节间长度基本上以15 cm等行距处理的最小,12 cm等行距处理的最大,这2种行距配置之间拔节期和开花以后的株高及成熟时基部节间长度差异均显著(P＜0.05)；而基部节间粗度、秆壁厚度、单位长度节间干重、茎秆机械强度及抗倒伏指数基本上以15 cm等行距处理的最大或较大,12 cm等行距处理的最小.起身期和拔节期喷施多效唑处理的小麦株高、节间长度和茎秆重心高度显著降低,基部节间粗度、秆壁厚度、茎秆机械强度有所增加,抗倒伏指数显著增大.除基部第二节间长度外,行距配置与化控互作对其他指标的影响不显著(P＞0.05).抗倒伏指数与株高、节间长度、重心高度呈极显著(P＜0.01)负相关(相关系数分别为-0.42、-0.76和-0.63),与茎秆机械强度、第1和第2节间单位长度干重、第2节间秆壁厚度呈显著或极显著正相关(相关系数分别为0.97、0.42、0.64和0.64),与第2、第3节间粗度和第3节间秆壁厚度相关不显著.因此,15 cm等行距种植配合起身期或拔节期多效唑化控,可提高小麦茎秆质量和抗倒性能.

Effects of Spacing Pattern and Chemical Control on Stem Quality and Lodging Resistance of Winter Wheat

In order to clarify the effects of spacing pattern and chemical control with PP₃₃₃ on stem quality and lodging resistance of winter wheat,a field experiment by split plot design was carried out,with spacing patterns (including 12 cm,15 cm and 12.5 cm + 12.5 cm + 20 cm) as main plots,and chemical control with PP₃₃₃ (including foliar spraying at erecting stage,jointing stage and control without any spraying) as split plots.The results showed that,the plant height,stem gravity height and basal internode length of wheat planted in 15 cm row spacing were all the shortest,and those in 12 cm row spacing were the tallest among the three spacing patterns.The differences of wheat plant heights at jointing and post anthesis,and the lengths of basal internodes between the two row spacing patterns were significant.However,the diameter,wall thickness and dry weight per cm length of basal internodes,stem mechanical strength and lodging resistance index showed the opposite trend among the three spacing patterns,i.e.,the values of these parameters of wheat planted in 15 cm row spacing were generally the highest or higher than that in 12 cm row spacing.The plant height,stem gravity height and basal internode length of wheat sprayed PP₃₃₃ at erecting or jointing stage were significantly shorter than those of control without any spraying.The diameter and wall thickness of basal internodes,and stem mechanical strength increased,and the lodging resistance index were significantly higher in wheat sprayed PP₃₃₃ at erecting or jointing stage,comparing with those of control.The lodging resistance index,which was the key criteria for lodging resistance of wheat,was significantly and negatively correlated with plant height (r=-0.42,P<0.05),stem gravity height (r=-0.76,P<0.05) and basal internode length (r=-0.63,P<0.01),but significantly and positively correlated with stem mechanical strength (r=0.97,P<0.01),dry weight per cm length of the 1st (r=0.42,P<0.05) and 2nd internodes (r=0.64,P<0.01) and the wall thickness of the 2nd internode (r=0.64,P<0.05),but it was insignificantly and positively correlated with the diameter of the 2nd and 3rd internodes and the thickness of the 3rd internode.According to the results,planted in 15 cm row spacing,combining with chemical control of PP₃₃₃ spraying at erecting or jointing stage,is beneficial to improve stem quality and increase lodging resistant ability of winter wheat.