顶端调控对棉花根系活力和养分吸收的影响

Effects of Smearing NAA or not after Decapitation on Cotton Root Activity and Nutrition Uptake

【目的】揭示新疆棉花栽培中打顶和顶端调控措施与棉花根系活力和养分吸收之间的关系。【方法】大田条件下,研究2个施磷水平在打顶和打顶后,涂抹萘乙酸对棉花根系活力和养分吸收的影响。【结果】在不施磷条件下,打顶第4 d打顶处理增加了根系活力和叶片中N、P、K养分的浓度,而到第9 d根系活力和叶片中N、P、K的浓度降低。施磷时无论打顶第4 d还是打顶第9 d打顶和打顶后涂抹萘乙酸都可增加棉花根系活力和叶片中N、P、K的浓度。施磷时无论是打顶还是打顶后涂抹萘乙酸都可增加棉花单株铃数、单铃重和单株籽棉产量。打顶时施磷比不施磷棉花单株铃数、单铃重、单株籽棉产量分别增加43.2%、26.0%、80.6%;打顶后涂抹萘乙酸分别增加46.0%、3.1%、50.5%。【结论】在施磷肥条件下,无论是打顶还是打顶后涂抹萘乙酸都可增加棉花根系活力,促进对养分的吸收,增加棉花产量。

[ Objective ] A field experiment was conducted to illustrate the effect of decapitation （ a con- ventional technique in cotton cultivation in Xinjiang） on cotton root activity and nutrition uptake. [ Method] The root activity and nutrition uptake was investigated after decapitation or decapitation with NAA -smearing under 0 or 375 kg/ha diammonium phosphate （DAP） applications. [ Result] Compared with that of decapita- tion with NAA - smearing under 0 DAP application, root activity and concentrations of nitrogen （ N）, phos- phorus （P） and potassium （K） in cotton leaves increased 4 days after decapitation, while these indicators de- creased when 9 days after decapitation. Compared with that of 0 DAP application, root activity and concentra- tions of N, P, K increased both 4 and 9 days after decapitation and decapitation with NAA - smearing with DAP application. Similar increments were observed on boll number of single plant, weight per boll and seed cotton yield per plant. Compared with that of 0 DAP application, boll number of single plant, weight per boll and seed cotton yield per plant increased by 43.2% 46.0%, 3.1%, 50.5% after decapitation with NAA 26.0% and 80.6% respectively after decapitation and - smearing. [ Conclusion ] Under DAP application, both decapitation and decapitation with NAA - smearing could improve root activity, promote nutrition uptake and increase cotton yield.