The Effects of Chemical Weed Control on Quality of Transplants Produced in the Plastic Tunnel and Final Yield of Leeks

In 2006-2008 there was conducted a study to determine the suitability of pendimethalin (Stomp 330 EC), glyphosate (Roundup 360 SL) and mixture of propachlor and glyphosate (Ramrod Flo 480 SC and Roundup 360 SL) as pre emergence herbicides in leek seedlings raising, and supplementary use of propachlor at the flag stage. The subject of evaluation was the efficiency of weed control, quality of transplants and finally the yield of leeks. Results of the study indicate that the efficient method of weed control during seedlings raising of leek was pre emergence use of pendimethalin at the rate of 990 g·ha-1 after seed sowing or mixture of propachlor (3840 g·ha-1) and glyphosate (720 g·ha-1) before seed emergence. Supplementary application of propachlor at the flag stage slightly increased the efficiency of chemical weed control but did not influence on the quality of transplants and yield of the crop. Chemical weed control did not adversely affect on the quality of seedling and yield of leek, except glyphosate which efficiency in weed control was not satisfactory. Heavy weed infestation during seedlings production diminished the quality parameters of transplants and yield of leek by 34.3%.