Journal of Research in Weed Science

Abstract Weed increase reduces crop yields, while chemicals applied to control weed have adverse environmental impacts. Thermal control has a less negative effect on the environment and health of consumers compared to chemical methods. After construction, the flame weeding efficiency of this method for eliminating near-row weed at three speeds of drive and three different amounts of liquid gas consumption was evaluated. The flame weeding manufactured and connected to the back of an offset tractor and navigation system. The flame weeding had a sidewall that prevented the flame from directly touching crop plants inside the row. Flame weeding were performed based on split-plots and on randomized complete block design with two factors of movement speed at three levels of low (3 km/h), medium (4 km/h) and high (5 km/h) and liquid gas consumption does at three levels of low (3 km/h), medium (5 km/h) and high (7 km/h). The results in both sugar beet and corn showed the interactive effects of two speed and amount consumption factors on each other. Weed control rates had varied considerably with flame treatment at different speeds and doses of liquid gas. With the increasing speed and decreasing liquid gas, the average weed control ratio decreased from 0.86 to 0.1. needle leaf weed control ratio in all cases is less than broadleaf weed. As the advance rate and the amount of liquid gas consumed decreases, the proportion of weed control declines substantially, and vice versa. This trend showed an inverse correlation between speed and liquid gas consumption factors.

Abstract Smallholder farmers have challenges of weed control and mostly they use cultural control methods because chemical control with herbicides is usually costly. However, Lantana camara L. is known to be allelopathic to other plants hence a worthy candidate for biological control of weeds under cowpea production. A field study was conducted to determine the potential for L. camara to control weeds in cowpea at the University of Zambia Agricultural Experimentation Station. Leaves were harvested from two genotypes of L. camara (G1: Pink-flowered and G2: Orange-flowered genotypes) dried and pulverized to form a powder and applied at different rates (R0C: 0 kg ha^-1, R1: 100 kg ha^-1, R2: 200 kg ha^-1, R3: 400 kg ha^-1) using the following types of application: T0C: No application, T1: broadcasting, T2: incorporation in the soil and T3: spraying of soaked ground L. camara. The research was conducted at the University Of Zambia School Of Agricultural Sciences Field Station. The experiment was arranged in a split split-plot design with three replications. Weed population density and weed weight were reduced the most (38% and 12.5%, respectively) at the highest rate (R3: 400 kg ha^-1) of L. camara application. The cowpea grain yield was higher (P< 0.05) in fields treated with G1 (mean =876.90 kg ha^-1) than for G2 (mean =672.10 kg ha^-1). G1 increased cowpea grain yield by 36.04%. Lantana camara holds great potential to increase food security by reducing losses associated with weeds in cowpea.

Abstract A field experiments was conducted at Professor Jayashankar Telangana State Agricultural University, Rajendranagar during kharif 2017 for the evaluation of diuron in two different soils. The treatments consisted of diuron 80% WP at 0.5, 0.75 and 1.0 kg ha^-1 along with registered formulation of pendimethalin 38.7% CS at 677 g ha^-1, intercropping with green manure crop, mechanical weeding thrice at 20, 40, 60 days after sowing and unweeded control. The experiment was carried out in a randomised block design replicated thrice. The weed flora of the experimental field in red soil was dominated by Cynodon dactylon, Rottboellia exaltata, Parthenium hysterophorus, Trianthema portulacastrum and Commelina benghalensis. While in case of black soil predominant flora was Cynodon dactylon, Cyperus rotundus, Parthenium hysterophorus, Euphorbia geniculata, Tridax procumbens, Cyanotis cristata, Digera arvensis and Celosia argentea. The macronutrient contents in cotton crop were higher in polymulch, mechanical weeding thrice at 20, 40 and 60 DAS and this was comparable to pre emergence application diuron at 1.0 kg ha^-1 followed by post emergence application of pyrithiobac sodium + quizalofop p ethyl in red soil and post emergence application diuron at 1.0 kg ha^-1 followed by post emergence application of pyrithiobac sodium + quizalofop p ethyl and diuron at 0.75 kg ha^-1 black soil. The minimum weed competition facilitated higher DMP and nutrient uptake by the plant. The nutrient removal by weeds also was minimal in polymulch, mechanical weeding thrice at 20, 40, 60 DAS, diuron at 1.0 kg ha^-1 pre emergence application of pyrithiobac sodium + quizalofop p ethyl followed by post emergence application of diuron at 0.75 kg ha^-1 in both red and black soil.