Chemical weed control in garlic ( Allium sativum L.) in Dongola Locality, Northern State, Sudan

Abstract

Weeds constitute one of the major biotic constraints that limit production of garlic Allium sativumL in Sudan A herbicides experiment in garlic was conducted during two consecutive winter seasons of the years 2011/2012 and 2012/2013 at the demonstration farm of Faculty of Agricultural Sciences- El Selaim-Dongola University-Sherg Elnil Unit-Dongola Locality Northern State-Sudan to determine the magnitude of yield losses due to weed competition and to evaluate the activity and selectivity of the pre-emergence herbicides oxyfluorfen as two formulations Pilargola 20 EC and Hadaf 24% EC each at 0 24 0 30 and 0 36 kg a i ha and pendimethalin Stomp 500 EC at 1 2 1 5 and 1 8 kg a i ha in controlling weeds in garlic Weeded and unweeded checks were included for comparison The weed flora in the experimental site consisted of grassy and broad leaved weeds The two formulations of oxyflurofen and pendimethalin at their all rates gave consistent and excellent control of graminae weeds throughout the growing season The two formulations of oxyflurofen gave satisfactory control of broad leaved weeds while the herbicide pendimethalin displayed poor to moderate activity Results obtained showed that within the three herbicides the best grassy and broad-leaved weeds control was achieved by the herbicide oxyflurofen asHadaf A significant weed controlwasachievedin terms of total weed biomass reduction with all herbicides treatments The better total weed biomass reduction was achieved by the highest rate of pendimethalin 1 8 kg a i ha In general the herbicides had an excellent and lasting effects on the control of weeds but the performance of these herbicides was greatly affected by the presence of the resistant weeds including Cynodon dactylon L Pers Cyperus rotundus L Convolvulus arvensis L and Rhynchosia memnonia Del DC Combined analysis of both winter seasons data indicated that unrestricted weed growth significantly reduced garlic yield by 36 08 This reduction in garlic yield was due effect of weeds on various yield components The combined analysis of both winter seasons data reported that all herbicides treatments significantly increased garlic bulb yield which varied from 21 95 to 57 14 The increase in garlic bulb yield as a result of the treatments of the herbicides mainly due to an increase in number of cloves bulb and increased bulb weight The combined analysis of both winter seasons data indicated that within all herbicides the best garlic bulb yield was achieved by the highest rate of pendimethalin at 1 8 kg a i ha and gave bulb yield comparable to weed free full season treatment Based on these results it can be concluded that the effectiveness of the herbicide pendimethalin at 1 8 kg a i ha against weeds and its high selectivity in garlic make this herbicide possible candidates for the control of weeds in garlic in the Northern State Sudan A significant increase due to herbicides treatments was also found in bulb weight g