豚草的剪叶实验研究

Effect of defoliation on growth and fruiting of ragweed.

豚草的剪叶实验研究结果表明:不剪叶的豚草株高可达222.3cm,单次剪叶平均株高为212.1cm,而连续多次剪叶时株高为184.0cm,连续6次全剪叶处理的植株在株高为130cm时死亡。不剪叶的植株结实枝条为14.9条。营养生长早期剪叶及重剪叶明显抑制枝条的形成,而后期剪叶有促进分枝的作用。剪叶对花穗数的影响与对分枝数的影响基本一致。不剪叶植株可产生1873.2粒种子,经剪叶处理后,种子量明显降低。大多数处理的种子减少率在40—70％之间,连续6次全剪叶的种子量减少率达100％。早期剪叶以及剪叶次数愈多,剪叶愈重,对豚草株高、结实枝、花穗数及种子量的抑制作用愈明显。

Field experiments show that the plant height of ragweed untreated reaches to 223.3 cm, while the average plant height is respectively 212.1 and 184.0cm after single and multiple treatment with defoliation. Plants with six times defoliation died when grew to 130cm in height. In control, the number of fruit-bearing branches is 14.9. With defoliation at early vegetative growing stages, the formation of branches is obviously restricted; whereas defoliation at later, the growth of lateral branches is stimulated. The influence of cutting leaves on the numbers of floret and branch is basically consistent. For the plants untreated, the number of seeds is 1,873.2, and that of treated plants is obviously decreased. When treated in vegetative growing stages, the number of seeds reduces to 40—70%, and after treated for six times, the seed reduction rate is 100%.