打顶后涂抹生长素对长绒棉生长和蕾铃脱落的影响

EFFECTS OF SMEARING NAA ON GROWTH AND FRUIT ABSCISSION OF COTTON(Gossypium barbadense L.) PLANTS AFTER DECAPITATION

与传统打顶处理相比,打顶后涂抹浓度为3×10-2mmol.L-1的α-萘乙酸(NAA),促进了上部植株的生长,植株上部生物量、成铃率分别比传统处理提高148.6%和96.6%,空果枝数降低52.6%,蕾铃脱落率降低43.1%;单株籽棉产量增加了26.4%。上述结果说明,生产中普遍存在的中后期“早衰”和“中空”现象与棉花打顶导致顶端优势丧失有关,打顶后涂抹NAA使植株的顶端优势得到一定恢复。

Compared with the conventional decapitation practice, smearing with 3 × 10^-2. mmol· L^-1 NAA （α- Naphthylacetic acid） after decapitation can increase biomass of the upper part of cotton plants by recovering of apical predominance, but had no significant effect on the middle-low part of plants. NAA smearing enhanced the weight of boll and boll retention rate by 148.6 % and 96.6%, respectively; NAA smearing decrease the number of empty branches and fruit abscission rate by 52.6% and 43.1%, which resulted in an increase in seed cotton yield per plant by 26.4 %. It was suggested that the phenomena of ＇premature senility＇ and ＇lack of bolls in middle part＇ during the cotton growth in Xinjiang may be partly attributed to the loss of apical predominance caused by decapitating.