多效唑对柠檬营养生长和生殖生长的影响

Effects of paclobutrazol on vegetative and reproductive growth of lemon

【目的】研究多效唑(PP333)对柠檬营养生长和生殖生长的影响,为柠檬生产上控梢促花、提高产量提供参考依据。【方法】柠檬树喷施400、600、800、1000、1200 mg/kg多效唑后,定期统计新梢数量、平均单枝花蕾数量,测定各处理果实纵横径、物理性状、产量等。【结果】喷施不同浓度PP333对柠檬树新梢萌发均有抑制作用,与对照(CK)相比,抑梢效果显著;喷施PP333后植株翌年平均单枝花蕾数量、开花量、着果量均比CK有不同程度增加,并能显著延长柠檬开花时间。平均单枝花蕾数、开花量最多的为800 mg/kg处理,平均单枝最大花蕾量比CK增加53.34%,平均单枝开花量是CK的1.83倍。在生长缓慢期,800、600 mg/kg处理分别对促进柠檬春花果和秋花果果实纵径增加效果明显,而在整个生长发育过程中,PP333对柠檬果实横径和果实物理性状的影响较小;PP333能显著提高柠檬单株产量和公顷产量,其中以800 mg/kg处理产量提高最明显,单株产量和公顷产量分别比CK增加41.07%和41.63%。【结论】适宜浓度的PP333可抑制柠檬树营养生长,促进生殖生长,以800 mg/kg处理效果最佳。

[Objective]The effects of paclobutrazol on the vegetative and reproductive growth of lemon were studied to provide theoretical and practical references for inhibiting new shoot, promoting flowering and improving yield. [Method] PP333 with 400, 600, 800, 1000 and 1200 mg/kg was sprayed to lemon trees for statistics of new shoot number and mean bud number per branch, and then determining transverse diameter, longitudinal diameter, physical properties, and yield in different treatments. [ Result ]The nmnber of new shoot was inhibited significantly with different PP333 concentrations compared with the control. PP333 caused marked increase in the flower bud per branch, and flowers and fruits per branch in the next year, and it could also lengthen blooming period significantly. Compared to the control, the number of flower bud and flower per branch were the most when the PP333 concentration was 800 mg/kg with the increase rate of 53.34% and 183%, respectively. The treatments of 800 and 600 mg/kg PP3~x caused increase of the longitudinal diameter of autumn- flowering lemon and spring-flowering lemon in slow growing period. PP333 had no influence on physical properties and transverse diameter during the whole growth period, while it could significantly increase the yield per plant and hectare yield. The yield per plant and hectare yield increased the most when the PP333 concentration was 800 mg/kg with the in- crease rate of 41.07% and 41.63%, respectively. [Conclusion]PP333 at the proper concentration could inhibit the growth of vegetative, and promote the growth of reproductive with concentration of 800 mg/kg being the optimal.