Effect of weed control treatments on the fresh and dry weight of total weeds and their weed control efficiency in carrot

摘要

Carrot (Daucus carota L.) is an important root vegetable grown in India. Low yields of carrot have been attributed to a number of factors of which weed infestation is a major problem. The chemical weed control is a worthwhile in this technological age (Ashton and Crofts, 1973). Good number of herbicides are available in the market, which can be used effectively and economically to control weeds in various vegetable crops including carrot (Bhalla and Parmer, 1982). A study has been carried out in carrot using different weed control treatments to findout their effect on weed growth and their control efficiency. The investigation was undertaken at the Division of Horticulture, UAS, Bangalore during rabi 1999. The experiment consisted of 15 treatments. The treatments comprised of 4 herbicides namely Alachlor, Pendimethalin, Linuron and Sethoxydim each at 3 different leveis, two cultural practices namely hand weeding at 15,30 and 45 DAS and organic mulching and one unweeded control. The experiment waslaid out in Randomized Complete Block Design with three replications. Observations on weed growth were recrded as the fresh and dry weight of total weed flora collected at 0.25 m~2 area in each plot at 30 DAS, 60 DAS and at harvest. To get the dry weight, the weeds were dried in oven till a constant weight was obtained. The efficiency of different weed control treatments was calculated using the following formula and expressed as percentage.