植物生长调节剂对叶菜产量及氮吸收的影响

Effects of Plant Growth Regulators on Yield and Nitrogen Uptake in Leafy-vegetable Crop

采用盆栽和田间小区试验研究4种不同浓度组合的植物生长调节剂对空心菜和小白菜的产量、硝酸盐含量和氮吸收利用的影响。结果表明,在减少50%常规施肥的条件下,喷施PGRs能提高2种叶菜的产量,降低其硝酸盐含量。与50%常规施肥相比,在盆栽条件下,PGRs处理使空心菜和小白菜鲜重分别增加2.9%～17.0%和18.7%～54.0%(P<0.05);田间试验下,使空心菜和小白菜产量分别增加13.6%～50.3%和30.8%～38.6%,其产量与常规施肥相当(P>0.05)。田间小区试验结果表明,与50%的常规施肥相比,PGR1处理使空心菜和小白菜硝酸盐含量分别降低了19.2%和19.8%(P<0.05);较之常规施肥分别降低了39.1%和32.2%(P<0.05)。而且,喷施PGRs能促进叶菜氮的吸收利用。与常规施肥相比,盆栽试验中PGR1处理小白菜氮含量显著增加(P<0.05),增加了7.3%;田间试验中,PGR2和PGR3处理的小白菜氮含量与常规施肥相当(P>0.05)。因此,外源合理施用PGRs能够保持叶菜作物高产,同时可提高蔬菜品质和养分吸收利用,达到减肥增效的目的。

Pot and field experiments were conducted to study the effects of 4 different plant growth regulators （PGRs） with 50% of conventional fertilizer（CF） on the yield, nitrates content and nitrogen absorption and utilization on water spinach and Chinese cabbage. Results showed that spraying PGRs under condition of 50% CF could improve the production of two kinds of leafy vegetables and reduce its nitrate content. Compared with 50% CF treatments, the water spinach and Chinese cabbage yield with PGRs treatments were increased from 2.9% to 17.0% and 18.7% to 54.0% in pot experiment, from 13.6% to 50.3% and 30.8% to 38. 6% in field experiments, respectively. Thus, the yields of PGRs-treated leafy-vegetable crop were similar to those of CF treatments（P〉0.05）. Moreover, the nitrate content of water spinach and Chinese cabbage was significantly reduced by 19.2% and 19.8% （P〈0.05）compared to 50% CF treatment, and by 39.1G and 32. 2% compared with CF treatment, respectively. In addition, foliar spray of PGRs also increased N content of water spinach and Chinese cabbage. Compared with CF treatments, the N content of Chinese cabbage was significantly increased by 7. 3% by PGR1 treatment in pot experiment and remained similar in field trial（P）0.05）, respectively. Therefore, a reasonable exogenous application of PGR with reducing the application rate of CF by 50% could maintain high production, improve vegetable quality, minimize fertilizer use, and increase nitrogen absorption of leafy crops.