扁杆藨草持续危害对棉花农艺和经济性状的影响

Effects of Continuous Damage of Bolboschoenus planiculmis(F.Schmidt)T.V.Egorova on Agronomic and Economic Traits of Cotton

【目的】研究扁杆藨草持续危害对棉花的影响,为棉田该杂草科学防治提供依据。【方法】扁杆藨草种群密度设为60株/m2,测定其持续危害0、10、20、30、40、50、60 d和全生育期棉花株高、茎粗、主茎节数、结铃数、单铃重、产量和纤维品质指标。【结果】棉花株高和茎粗随扁杆藨草危害持续期延长而减小。扁杆藨草持续危害期小于30 d,对棉花主茎节数和果枝数影响不显著,大于30 d则显著减少。扁杆藨草持续危害期对棉花中部和下部果枝结铃数影响不显著,显著引起上部果枝结铃数、单铃重减少。扁杆藨草持续危害期大于10 d,可使棉花产量显著减少,导致棉纤维品质指标下降。【结论】依据棉花产量指标,扁杆藨草防除应不晚于棉花打顶前30 d。

【Objective】To study the effect of continuous damage of Bolboschoenus planiculmis on cotton in the hope of providing a basis for scientific control of this weed in cotton fields.【Methods】The population density of Bolboschoenus planiculmis was 60 plants/m2 in this experiment.The plant height,stem thickness,main stem node number,knot number,single boll weight,yield and fiber quality index of cotton were determined,which were continuously harm by Bolboschoenus planiculmis for 0,10,20,30,40,50,60 d and the whole cotton growth period.【Result】The plant height and stem thickness of cotton decreased with the duration of the damage of Bolboschoenus planiculmis.When the continuous damage period of Bolboschoenus planiculmis was less than 30 days,there was no significant effect on the number of main stem nodes and fruit branches of cotton,but significantly less than 30 d.The continuous damage period of Bolboschoenus planiculmis had no significant effects on the number of bolls in the middle and lower fruit branches of cotton,but the number of bolls and the weight of single bolls on the upper fruit branches significantly decreased.When the continuous damage period of Bolboschoenus planiculmis was more than 10 days,it could significantly reduce the cotton yield and cause the cotton fiber quality index to decrease.【Conclusion】According to the cotton yield index of this experiment,the Bolboschoenus planiculmis should be removed no later than 30 days before the cotton topping.