The Chemical Capping Regulation Mechanism of Cotton Main Stem Growth

In China, due to labor shortages and increasing costs, manual topping is gradually being replaced by chemical capping with mepiquat chloride (DPC). External chemicals can adjust plant growth affecting endogenous hormones. Based on the hormone changes combined development of main stem cotton plants, a comparative experiment was conducted in 2019 2020 determine regulatory mechanism after capping. experiment, two treatment times (T1: 12 July, T2: 18 July) agents (CA [chemical agent] DPC) were set, (auxin IAA, abscisic acid ABA, Gibberellin GA3 Zeatin ZR) concentrations at top (0–5 5–10 cm) continuously measured situation observed recorded. The results showed that capping, IAA concentration decreased firstly increased later, lower than CK. ABA significantly compared ZR fluctuated obviously T1 gently T2. terms growth, height, number fruit branches average length upper internode (fifth above) CK, while CA inhibited more strongly DPC treatment. To conclude, operation affected apex effectively regulated development. comparison treatment, hormones effectively, which favorable for conducive reasonable shaping.