Studies On Chemical Weed Control In Transplanted Pepper (Capsicum Fruitescens L.)
Two field experiments were conducted during 2006 and 2007 to evaluate the performance of three herbicides for weed control in transplanted pepper at the Universit), of Ghana Farm. and Pokuase (a farming community) in the Greater Accra Region of Ghana. The three herbicides, Oxyfluorfen, Pendimenthalin and Propaquizafop were each applied at three different rates based on the manufacturers recommended ranges of (1, 2 and 11,114, (2, 2.5 and 31,117a) and (1, 1.5 and 21,/ha) respectively. A randomized complete block design was employed and there were eleven treatments and four replicates. Hand weeding and no weeding were used as controls. Pre-emergence herbicides were applied immediately after land preparation and prior to weed emergence and post emergence herbicide was applied four weeks after transplanting when weed cover was more than sixty percent. Pepper seedlings were transplanted four weeks after planting. The results showed that Oxyfluorfen and Pendimenthalin, which are pre-emergence herbicides, controlled both broadleaved weeds and grasses efficiently in chilli pepper up to about the tenth week after transplanting and plots required only one supplementary hand-weeding. Propaquizafop, which is a post-emergence herbicide, also controlled grasses effectively in the production of chilli pepper but its application required two supplementary hand-weeding of plots. Among the three herbicides applied at three different rates, Oxyfluorfen was the most effective at controlling both grasses and broad-leaf weeds. Plant growth, fruit characteristics and yield of pepper were increased by the application of Pendimenthalin and Oxyfluorfen although the effect of Pendimenthalin was better than Oxyfluorfen. Plants on Pendimenthalin treated plots at 2L/ha significantly had the highest yield while Oxyfluorfen at 3.0L/ha had the lowest yield in the Legon study. In the Pokuase study, Pendimenthalin at 2.5L/ha had the highest yield while Oxyfluorfen at I .0L/ha and 3.0L/ha had the lowest yield Cost analysis revealed that Oxyfluorfen was the most cost effective method of controlling weeds in hot pepper production.