通辽地区紫花苜蓿田杂草种类及发生规律的调查研究

通过对紫花苜蓿田杂草种类及发生规律的调查研究，表明通辽地区紫花苜蓿田有13科31种杂草，以一年生杂草为主；优势杂草藜、酸模叶蓼、打碗花、稗、反枝苋等呈集群分布；主要杂草发生时间在紫花苜蓿播种后10d左右进入出苗高峰期；一年生杂草大量发生时间在5～6月份，二年生和多年生杂草易常年发生；以禾本科稗草，阔叶类杂草藜、反枝苋、酸模叶蓼、打碗花发生最为普遍，危害严重。

Investigation of Weed Species and Occurrence Regulator on Fields of Alfalfa in Tongliao

In this paper, we can showed 31 varieties of weeds of 13 families with alfalfa fields in Tongliao byinvestigation of weed species and occurrence regulator of alfalfa, however annual weeds are main; The superiorityweeds chenopodium album, polygonum lapathifolium, calystegin hederacea, redroot amaranth and amaranthusretroflexus etc appeared clump distribution; It happened 10 days after alfalfa planting and entering the height period around; Annual weeds occurrence 5 ~ 6 month had large quantity; biennial and perennial weeds occurrenceeasier and throughout the year; The Gramineae weeds redroot amaranth, broadleaf weeds chenopodium album,amaranthus retroflexus, polygonum lapathifolium and calystegin hederacea happened usually and hazard very serious.