【作者】 刘萍；

【导师】 李卫军；

【作者基本信息】 新疆农业大学 ， 草业科学， 2002， 硕士

【摘要】 苜蓿种子生产过程中，杂草是影响苜蓿种子数量和质量的关键问题之一。本文研究了不同利用年限苜蓿种子田杂草种类成分、出草规律、生育期、土壤种子库及其活力，探讨了不同防治方法在苜蓿种子田的除草作用。研究发现，利用一年苜蓿种子田田间杂草出草有二个高峰。第一高峰由一年生春性杂草组成，第二高峰由一年生春性和一年生夏性禾本科杂草组成。利用二年苜蓿种子田杂草出草呈增长、下降、稳定的趋势，主要为一年生春性杂草。利用三年苜蓿种子田杂草出草高峰是由一年生夏性禾本科杂草决定的。不同利用年限的苜蓿种子田，在0～5cm土层内有活力杂草种子数及其平均活力明显高于5～10cm的上层。8月份土壤种子库中有活力杂草种子数及其平均活力明显低于3月份，其主要原因是一系列的防治措施及苜蓿生长竞争力的提高。 本文研究了不同利用年限苜蓿种子田杂草防除措施。利用一年种子田综合防除措施为：在苜蓿返青后，喷施土壤处理剂施田补，并在一周内浅中耕混土以防治一年生杂草，对仍存活杂草和后期出现的杂草进行人工除草一至二次；在苜蓿后期和收割后，可沿苜蓿行间喷洒2，4-D丁酯，以杀除田旋花及其他阔叶多年生杂草。利用二年、三年种子田综合防除的最佳组合：早春苜蓿返青初期，土壤处理剂氟乐灵或施田补结合耙地，或者苜蓿返青后，施田补结合浅中耕以防治一年生杂草，4月中下旬中耕以防除行间部分一年生杂草和多年生杂草，苜蓿封垄前和苜蓿收割后的田旋花可沿苜蓿行间喷洒2，4-D丁酯防除。更多还原

【Abstract】 Weeds are one of the critical factors that affect quantity and quality of alfalfa seed in the course of alfalfa seed production. Weed species, germination ,seed bank in soil and seed vigor were studied in alfalfa seed-producing field of different utilized years. There were two germination peaks in the utilized first year field. The first peak was composed of annual spring weeds; the second was composed of both annual spring weeds and annual summer weeds. The number of annual weeds presents increasing, descending and stabilizing trend in the utilized second year field. The annual summer weeds determine the peak in the utilized third year field. The seed vigor and the number of active seeds in 0?cm layer of soil are higher than those in 5~ 10cm layer. The number of active seed and their vigor in August is lower than those in March. The main reason that leads to decline is weed control and improvement of alfalfa competition.The method of weed control in different utilized year field was suggested in this research. The managing technique of weed control in the utilized first field was established by using Pendimethalin combiningwith shallow intertilling and raining after germinating, artificial control for weeds that still survive and germinate was carried on once or twice, and other perennial weeds and Convolvulus arvensis were sprayed Butoxone along the alfalfa line. The best managing method in the utilized second year and third year field was established by Trifluralin or Pendemethalin combining with harrowing or Pendemethalin combining with shallow intertilling in the early days of germination, the intertilling was carried on in the last of April in order to control annual and perennial weeds, Butoxone may control Com:olvulus arvensis.更多还原