外源赤霉素对纽荷尔脐橙容器大苗花芽分化的影响

本试验以枳壳为砧的纽荷尔脐橙2年生容器大苗为试材，分别于2013年、2014年连续两年研究了不同喷药时期（10月到次年2月），不同赤霉素浓度（200ppm、300ppm、400ppm、500ppm）抑制花芽分化的效果。结果表明：各浓度均产生抑制效果且效果显著优于对照，当喷药时间为11月5日左右时，赤霉素浓度为300ppm，花枝明显减少，营养枝比例多，抑制花芽分化效果较好，但各处理间差异不显著。喷施浓度过高会导致叶片呈现细长型，喷施时间推迟抑制效果减弱。同时研究了从11月5日开始每隔半个月喷药一次，连续喷药三次，喷药浓度分别为50ppm、100ppm、200 ppm、300 ppm、400 ppm、500 ppm ，以不喷药为对照，抑制花芽分化的效果，结果表明：各浓度均产生抑制效果且效果显著优于对照，但各处理间差异不显著，且随着喷施浓度的升高，叶片呈现细长型，因此综合考虑当浓度为50ppm时，抑制效果较好。

Effect of exogenous gibberellic acid treatments on flower bud differentiation of Newhall orange container

In 2013 and 2014, gibberellic acid treatments were tested on Newhall orange of 2 years container with the aim of inhibiting flower bud differentiation. Different gibberellic acid concentrations (200ppm,300ppm,400ppmand 500ppm) and various application dates(October to February of next year) were evaluated. The result showed that when the concentration of gibberellin is 300 ppm and spraying time of which is every year on November 5 is better inhibition of flower bud differentiation. Flower quantity decreased significantly, proportion of vegetative branches is more. At the same time, different gibberellic acid concentrations (50ppm,100ppm,200ppm,300ppm,400ppmand 500ppm) and continuous spraying three times (each year starting on November 5, spray once every half a month) were evaluated. Throughout the trial, the treatments gave better results than the contrast,but the differences between the groups were not significant and with the increase of spraying concentration, blades were slender. So the low concentration(50ppm) is better to inhibiting flower bud differentiation.