Design, Construction and Evaluation of Flame Emission Apparatus to Control Weeds Between Faba Bean (Vicia faba) Ridges, River Nile State, Sudan

Abstract

The performance of designed and constructed flame emission apparatus using liquefied petroleum gas (LPG) was evaluated to control weeds between ridges in River Nile State. In the first season, different operative parameters were tested including two types of atmospheric burners hanged at 12cm height from soil surface, driven forward at 30o and 45 o angle at walking speeds of 11, 18 and 27m/min. The fuel consumption per hour and temperature for each burner were measured in the laboratory experiment. In season 2004-05 a field experiment with the combination of the above parameters was executed to control weeds in faba bean at 4, 5 and 6 weeks after sowing (initiative flowering stage and initiative pod setting stage). VIII From the results of this season, the relation between fuel consumption (kg hr-1 and kg ha-1) and weeding efficiency were assessed, using the burner with 1mm orifice diameter directed at 30o angle and driven at 11m/min. In the following two seasons, an experiment was conducted to evaluate flame weeding at 4 and 6 weeks after sowing, and another experiment for comparison with hand weeding and pre-emergence herbicides. The experiments were arranged in randomized block design with 6 and 4 replications respectively. The flaming apparatus showed reasonably high efficiencies, to control grasses and broad-leaved at 4 weeks after sowing the efficiencies were 72.4% and 77.8% respectively. Comparison of means of total weeding efficiency at different weeds developmental stages showed that flaming at 4 weeks after sowing was comparable with hand weeding at the same period in the first season, and with pre-emergence herbicides; free weed and hand weeding in the second season. With regards to comparing the flame weeding with the usually pre-emergence herbicides and hand weeding, statistical analysis showed no significant difference in total weeding efficiency in the first season between the three methods, but there was significant difference (P>0.01) in the second season. This can be attributed to the large number of grasses which were difficult to be controlled, compared to broad-leaved weeds. The grain yield of faba bean flamed at 4 weeks after sowing was comparable with the yield of pre-emergence herbicides and hand weeded plots in the two seasons. Economic analysis of using flame weeding at 4 weeks after sowing resulted in 562% and 1094% marginal rate of return in the two seasons, where herbicides application gave 90% and 314%, the analysis excluded hand weeding which appeared economically not feasible. It is apparent that flaming apparatus shows promising results in terms of weeding efficiency and economic feasibility