Effects of topping on agronomic traits and yield of Lablab purpureus

Different topping treatments of Lablab purpureus plants at 2-9 leaf stage were carried out in two areas of Shanghai and Heilongjiang to investigate the topping effect on the agronomic traits and yield.The experimental results showed that topping the plants at 2-5 leaf stage could effectively control the plants' sprawling character,decrease the plant height,lower the degree of lodging to 1.3-2.4 levels,make the flowering time 7.3-10.7 days earlier and the picking time 4.6-8.3 days in advance,and reduce the fresh haulm weight by 58.0%-76.7%;The number of fresh pods was 34.0-50.7 per plant,the fresh pod weight was 283.3-403.5 g per plant,and the economic coefficient was 0.216-0.405.