Efficacy of pre-emergence and post-emergence herbicides for weed management in groundnut (Arachis hypogaea L.) production in Guinea Savannah

Abstract

Groundnut or peanut (Arachis hypogaea L.) has gained prominence as food and cash crop both in the domestic and export markets. In Ghana, the bulk of groundnut is produced in the Guinea savannah zone where it is vulnerable to weed infestation that results in average yields of about 800 kg/ha compared to developed countries of more than 3,000 kg/ha. This experiment was conducted in Tolon during the 2012 farming season to determine the most suitable combination of pre-emergence and post-emergence herbicides and/or hand weeding that could enhance efficient weed control and to assess the treatments that could promote yield and yield components of groundnut. Some local available herbicides and recommended rates used included: Pendimethalin at 0.15 kg a.i./ha, gallant super at 0.03 kg a.i./ha, agil at 0.02 kg a.i./ha, basagran at 0.14 kg a.i./ha. The study was laid out in RCBD with four replications. Results showed Pendimethalin at 0.15 kg a.i./ha plus gallant super at 0.03 kg a.i/ha at 4 weeks after planting (WAP) recorded the highest pod yield of 2436 kg/ha. All treatments recorded significantly high yield over the Weedy check. Weed biomass correlated negatively (r= -0.5074) with nodulation count while haulm yield showed a positive correlation coefficient of (r=0.4575*) with pod yield. Weed control efficiency of 94.8% showed pendimethalin at 0.15 kg a.i/ha plus agil at 0.02 kg a.i/ha at 4WAP was most effective in weed control. Herbicide application reduced weed index. Basagran at 0.14 kg a.i/ha at 4WAP plus one hand weeding at 7WAP recorded least weed index of 24%. The most dominant weeds were broadleaves such as Ageratum conyzoides (L), Corchorus olitorius (Linn) and Ludwigia abyssinica (A. Rich). Plots with uncontrolled weeds resulted in 69% loss of pod yield. In order of decreasing weed control, yield components and pod yield; Pendimethalin at 0.15 kg a.i./ha plus gallant super at 0.03 kg a.i/ha applied at 4 WAP was more effective than basagran at 0.14 kg a.i/ha at 4WAP plus 1HW at 7WAP and gallant super at 0.03 kg a.i/ha at 4 WAP plus 1HW at 7 WAP; and are recommended in that order to groundnut farmers in the Guinea savanna zone of Ghana.

Influence of herbicides under biofertilizer application on fennel (Foeniculum vulgare) yield and quality with special reference to herbicide residues

“…Similarly, Kumar and Tewari (2004) found that pendimethalin (1.0 and 1.25 kg ha −1 ) as pre-emergence herbicide for grass and broadleaf weeds followed by fluazifop-p-butyl (0.250-0.375 kg ha −l ) as selective post-emergence grass herbicide, enhanced weed control spectrum resulting in increased black gram grain yield over sole application of each one due to lowered weeds' density and dry weight. Same trends were obtained by Wilfred et al (2020) as they reported that pendimethalin + haloxyfop-P-methyl (chemically related and biologically similar to fluazifop) resulted in the best growth characteristics, yield components and yield of groundnut as an oilseed crop in Guinea Savannah. Hassanein et al (2002) pointed out that the application of pre + post-emergence herbicide in soybean significantly increased plant height, number of leaves, dry weight of leaves and total dry weight of plant and gave the highest weight of pods/plant, 100-seed weight and seed yield/ fed, compared with the unweeded treatment.…”

Combination of organic soil amendments and weed control to optimize the growth and yield of peanuts in sandy soils in coastal areas

“…Oxyfluorfen appeared less effective for sedges and grasses. This phenomenon can be explained because the sedges and grasses grow from the vegetative parts of weeds that develop several weeks after planting, so the control with preemergence herbicides becomes ineffective [32,33].…”