化学调控对谷子茎秆性状及其籽粒产量的影响

Effects of chemical regulation on stem traits and grain yield of foxtail millet

【目的】通过在谷子不同生育时期叶面喷施多效唑和乙烯利,探讨两种植物生长调节剂配合喷施对谷子茎秆特征、抗倒性、灌浆及产量的影响,为谷子的化学调控和高产栽培提供理论依据。【方法】试验以张杂谷10号为供试材料,设多效唑浓度为300 mg/L分别在拔节期前、拔节期、孕穗期喷施,乙烯利浓度为400 mg/L分别在孕穗期、抽穗期以及灌浆期喷施,并测定谷子的形态指标、茎秆机械强度、穗颈节间性状、灌浆速率及产量。【结果】与对照相比,除A3B3、A3B1处理外,其他各处理茎粗均有所增加,其中在A_(1)B_(2)处理时达到最大,茎秆N1、N2和N3节间的茎粗显著增加了11.96%、12.72%和9.61%。茎秆节间长度则在A_(1)B_(2)处理时达到最小值,N1、N2、N3和N4各节间长度较对照显著缩短了47.61%、41.75%、44.75%和32.29%。谷子茎秆的各节间干质量同样以A_(1)B_(2)处理增加幅度最大,N1、N2、N3和N4各节间干质量分别较对照增加43.42%、55.84%、42.69%和31.95%。因多效唑与乙烯利对株高的影响,植株重心高度随之变化,表现为随株高的下降,重心高度渐降,在A_(1)B_(2)处理时最低,较对照显著降低36.04%。除A3B1、A3B3处理外,其他各处理的谷子基部各节间弯曲力矩和倒伏指数较对照减少,抗折力增大,抗倒伏能力增强,各参数均在A_(1)B_(2)处理时最佳。穗颈节间方面,谷子穗颈节每厘米干物质量在A_(1)B_(2)处理时最大,与对照相比增加54.54%,穗颈节含水量也随之变化,较对照降低33.12%。同时穗颈节弯曲力矩减少,抗折力增大,均在A_(1)B_(2)处理时最好。在灌浆中期,各处理的灌浆速率均达到最大,其中以A_(1)B_(2)、A_(2)B_(2)、A_(2)B_(1)处理效果最明显。产量方面,A_(1)B_(2)、A_(2)B_(2)、A_(2)B_(1)处理的产量较对照显著增加了23.82%、19.31%、8.35%,其他处理不显著,但A3B3、A3B1处理下谷子产量显著低于对照,分别减少6.51%、9.05%。与产量趋势相一致,穗质量、穗粒质量、千粒质量同样在A_(1)B_(2)处理时达到最大,但A3B3、A3B1处理下谷子穗粒质量显著低于对照,A3B1处理下的千粒质量较对照也显著降低。【结论】张杂谷10号在拔节期前或拔节期喷施300 mg/L多效唑后,在抽穗期再喷施400 mg/L乙烯利最适宜,而在孕穗期喷施多效唑后,孕穗期或灌浆期再喷施乙烯利会造成减产。

【Objective】In order to provide theoretical basis for chemical regulation and high-yield cultivation of foxtail millet,the effects of two plant growth regulators on the characteristics of stem,lodging resistance,grain filling and yield of millet were studied by spraying paclobutrazol and ethephon on the leaf surface of millet at different growth stages.【Method】‘ZhangzaGu 10’was used as the test material.Paclobutrazol(300 mg/L)was sprayed before jointing stage,jointing stage and booting stage respectively,and ethephon(400 mg/L)was sprayed at booting stage,heading stage and filling stage respectively.The morphological indexes,stem mechanical strength,panicle neck internode characters,grain filling rate and yield of foxtail millet were determined.【Result】Compared with the control,except for A3B3 and A3B1,the stem diameter of other treatments increased,and reached the maximum in A_(1)B_(2)treatment.The stem diameter of N1,N2 and N3 internodes increased by 11.96%,12.72%and 9.61%significantly.The internode length of N1,N2,N3 and N4 was significantly shortened by 47.61%,41.75%,44.75%and 32.29%compared with the control.The dry weight of stem internode of millet was also increased by A_(1)B_(2)treatment.The dry weight of N1,N2,N3 and N4 increased by 43.42%,55.84%,42.69%and 31.95%respectively,compared with the control.Because of the effect of Paclobutrazol and ethephon on plant height,the center of gravity height changed with the decrease of plant height,which was the lowest in A_(1)B_(2)treatment,which was significantly reduced by 36.04%compared with the control.Except A3B1 and A3B3,the bending moment and lodging index of the internode at the base of millet in other treatments were decreased compared with the control,the flexural resistance was increased,and lodging resistance was enhanced.All parameters were the best in A_(1)B_(2)treatment.In the aspect of panicle neck internodes,the dry matter weight per centimeter of panicle neck internodes of millet in A_(1)B_(2)treatment was the largest,increased by 54.54%compared with the control,and the water content of panicle neck internodes also changed,decreased by 33.12%compared with the control.At the same time,the bending moment of panicle neck internodes decreased and the bending strength increased,which were the best in A_(1)B_(2)treatment.In the middle stage of grouting,the grouting rate of each treatment reached the maximum,and the effect of A_(1)B_(2),A_(2)B_(2)and A_(2)B_(1)treatment was the most obvious.In terms of yield,the yields of A_(1)B_(2),A_(2)B_(2)and A_(2)B_(1)treatments were significantly increased by 23.82%,19.31%and 8.35%compared with the control,but the yields of A3B3 and A3B1 treatments were significantly lower than the control,and decreased by 6.51%and 9.05%respectively.Consistent with the yield trend,panicle weight,grain weight of panicle,and 1000-grains weight also reached the heaviest in A_(1)B_(2)treatment,but the grain weight of panicle in A3B3 and A3B1 treatment was significantly lower than that in the control,and the 1000-grains weight in A3B1 treatment was also significantly lower than that in the control.【Conclusion】It was best to spray 300 mg/L paclobutrazol before or at jointing stage,and then to spray 400 mg/L ethephon at heading stage.After spraying Paclobutrazol at booting stage,spraying ethephon at booting stage or grain filling stage would cause yield reduction.