入侵杂草五爪金龙在切割处理下的再生能力

对五爪金龙(Ipomoea cairica (Linn.) Sweet)进行切割试验,对其在不同光环境及不同季节的萌芽率、成活率、主茎长度和生物量等进行研究。结果表明:五爪金龙切条越短其萌芽越迟,其成活率、主茎长度和生物量下降;五爪金龙在光下和林下的成活率无显著差异,但林下生物量较低;切条越短,林下条件越不利于主茎的伸长;冬季五爪金龙的主茎长度和生物量最低;夏季在光下和林下不能再生的最长切条长度均为4 cm;秋季均为1 cm;而冬季光下为1 cm,林下为3 cm;春季光下则为4 cm,林下为5 cm。春季时将五爪金龙切割为5 cm并置于林下是最经济的防除方法;如果不考虑季节性及光条件,应将其切割至1 cm以下的片段,可以有效防止五爪金龙再生。

Regeneration of An Invasive Weed Ipomoea cairica under Cutting Treatments

The survival, main stem length and biomass of Ipomoea cairica cuttings were studied under different light environments and different seasons. The results showed that the survival, main stem length, and biomass of I. cairica gradually decreased and the cutting germination delayed with the cutting length decreased. The survival of I. cairica had no significant difference under sunlight and the understory, and the plant biomass was less in the understory than that under the sunlight. The shorter cuttings were not subject to lengthen the main stem in the understory. The main stem length and biomass in winter were the lowest among four seasons. The longest length of the cuttings which can't regenerate was 4 cm under the sunlight and 5 cm in the understory in spring, 4 cm in summer, 1 cm in autumn, and 1 cm under the sunlight and 3 cm in the understory in winter, respectively. Therefore, it was economical removing method that I. cairica branches were cut into 5 cm length segments in spring, and put them in the understory. Without considering the seasonal and light conditions, less than 1 cm of the cuttings should be selected in order to effectively avoid the regeneration of I. cairica.