Pre-tillage control of spear grass (Imperata cylindrzca [L.] Raeuschel) with Glypnosate for soya bean (Glycine max [L.] Merr.) production in Nigeria

No Abstract Available E. Afr. Agric. For. J Vol.68(3) 2003: 155-15

Studies on reproductive abscission and seed yield of mungbean (Vigna radiata) in sub-humid savanna of Nigeria.

A field study was conducted on the Research and Experimental Farm of the University of Agriculture Makurdi (7o41’N, 08o37’N, and 400 m above mean sea level), Nigeria, in 2001 and 2002 to examine the abscission of reproductive structures in mungbean (Vigna radiata). Four exotic cultivars (VC 2768A, VC 1178A, VC 2778A and VC 1973A) and a local cultivar (Ex–Zaria) were used for the study, which was laid out in a randomized complete block design and was replicated four times. Grain legumes generally undergo considerable abscission of their reproductive structures during flowering and fruiting stages. In this study the abscissions of flowers and pods differed widely among the cultivars. The abscissions of flowers and young pods varied from 14.4 to 36.8% and 12.3 to 38.5%, respectively. The number of flowers and harvestable pods per plant also varied from a high of 77.2 and 48.8 in VC 2768A to a low of 49.1 and 24.0 in VC 2778A, respectively. Conversely, young pods varied in number from 56.0 in VC 1973A to 38.9 in VC 2778A. In all the cultivars, more flowers occurred at the bottom of the canopy where abscission was also highest. The cultivar VC 2778A had highest (50.8) percent total abscission compared to the lowest of 29.1percent in VC 1973A. Seed yield ranged from 541.67 kg/ha in VC 2778A to 2000.2 kg/ha in VC 2768A. Seed weight and the number of seeds per pod, however, did not vary significantly. There was a high positive correlation (r = 0.94) between flowers and harvestable pods. Seed yield also correlated positively with the number of flowers, harvestable pods, seed weight and the number of seeds per pod.This study has shown that reproductive abscission exists in mungbean but it is of less intensity when compared to other legumes. The lower rate of abscission coupled with low incidences of pests and diseases and high nutritive value make the crop a dependable source of protein for resource-poor rural farmers in the tropics

Evaluation of Fluazifop-P-Butyl and Propanil for Weed Control in Sesame (Sesamum indicum L.) in Southern Guinea Savanna, Nigeria

Aims: To evaluate the effects of rates of the post-emergence herbicides Fluazifop and Propanil for weed control in sesame (Sesamum indicum L.) grown in Makurdi. Study Design: Randomized Complete Block Design. Place and Duration of Study: The trials were conducted in the growing seasons of 2009 and 2010 at the Teaching and Research Farm of the University of Agriculture, Makurdi (07º 41´N and 08º 37´E) in the Southern Guinea Savanna zone of Nigeria. Methodology: The eight (8) treatments consist of three rates of Fluazifop (0.15, 0.22 and 0.30 kilogram active ingredient per hectare (kg a.i./ha) and three rates of Propanil (0.72, 1.44 and 2.16 kg a.i./ha), hoe-weeded at 3 weeks after planting (WAP) and a weedy check. The sesame seeds (variety “E8”) used for trials was planted by broadcasting on plot sizes of 5m×4m (20m2). The herbicide applications were carried out as post-emergence at 15 days after planting. Fertilizer NPK (20:10:10) was applied at 4 WAP at the rate of 150 kg ha-1 by broadcasting. Results: The three rates of Fluazifop significantly controlled grasses without any crop injury. However, Propanil controlled both grasses and sedges, but on broadleaf weeds, the effect increased with increasing at 4 WAP. Grain yield was highest (858 kg ha-1) at 0.72 kg a.i./ha of Propanil, that was followed by treatments that received 1.44kg a.i./ha of the same herbicide. The least grain yield (467 kg ha-1) was obtained with the weedy check. Conclusion: The highest benefit-cost ratio of 3.53 was obtained from Propanil at rate of 0.72kg a.i./ha. This is an indication that Propanil could be used to control weeds in sesame to boost its productivity in the study area

Options for cogongrass ((Imperata cylindrica) control in white guinea yam (Dioscorea rotundata) and cassava (Manihot esculenta)1

Cogongrass is a serious weed in small-scale farms in the lowland humid zone of West Africa. This study evaluated the response of cogongrass to herbicides and the legume cover crop velvetbean in cassava and white Guinea yam. In 2001/2002, cassava tuber yields and gross returns in treatments that received glyphosate alone were higher than in plots that received fluazifop-P-butyl once. In 2002/2003, treatments that received fluazifop-P-butyl once, glyphosate alone, glyphosate integrated with sowing velvetbean, or hoeing only, had higher cassava tuber yields than other treatments. Gross returns were higher in treatments that received glyphosate followed by sowing velvetbean or those hoed only than in other treatments. Fluazifop-P-butyl applied twice, glyphosate alone, or glyphosate followed by sowing velvetbean reduced cogongrass shoot biomass more than other treatments. Rhizome biomass was lower in plots that received glyphosate alone than in all fluazifop-P-butyl treatments. In 2002, white Guinea yam tuber yields were highest in plots that received glyphosate alone and lowest in plots where fluazifop-P-butyl was applied alone or followed by sowing velvetbean. The highest gross return was obtained in plots that received glyphosate alone while the lowest was obtained in plots that received fluazifop-P-butyl once followed by sowing velvetbean. In 2003, the highest tuber yields and gross returns were from plots that received glyphosate alone, fluazifop-P-butyl alone, or those hoed only. The hoed-only plots had 14 times higher cogongrass shoot biomass and 7 times higher rhizome biomass than other treatments. In both crops, hoeing alone or followed by sowing velvetbean was more costly than chemical control. The highest margin over hoeing was obtained from plots that received glyphosate alone. Sensitivity analysis showed that using glyphosate was more cost effective than fluazifop-P-butyl, even if the cost of the herbicide increased by 100% or the cost of labor decreased by 30%

Farmers perceptions of the speargrass (Imperata cylindrica) problem and its control in the lowland subhumid savannah of Nigeria

Speargrassseverely constraints crop production in the sub-humid lowlands of West Africa. Researchers have identified and demonstrated effectivemanagement techniques but the adoption rate among farmers is still low. Data were collected from 41 communities in Cross River, Kogi and BenueStates in Nigeria using rural rapid appraisal techniques. The objectives were to assess the importance of agriculture in the livelihoods of eachcommunity, identify priority crops, assess perceptions of the speargrass problem, identify existing speargrass control strategies and localinstitutions/farmers with the capacity to implement speargrass control trials. Crop production was the main source of livelihood for all households.The most important crops from the perspectives of both food security and cash sale were cassava and yam, and these were most affected by theweed. Speargrass was the major constraint to crop production because of lack of capital for hiring labour and purchasing inputs, declining soilfertility, bush burning, deforestation, continuous cropping and lack of required skills. Slashing, hand-pulling, burning, deep digging and fallowingwere the most common control methods used by farmers, but these were very labour intensive and ultimately not effective. Farmers assessedspeargrass control measures through labour and cash requirements, material availability, effectiveness, time span to achieve control and cropyields. They rated chemical control most highly. Longer fallow periods and re-afforestation were effective but impractical as pressure on landintensifies from population growth. From the results of this study, we conclude that the use of community-based participatory a pproaches is essential to identify various technologies for combating speargrass

Promoting integrated management practices for speargrass (Imperata cylindrica (L) Raeusch.) in soybean, cassava and yam in Nigeria

Speargrass is a serious weed in many farming systems of West Africa. Participatory research and extension approaches were used to promote farmer testing of alternative speargrass management options in yam, cassava and soybean in Nigeria. Treatments were paired plots with a farmers' control and at least one improved control option. The farmers' practice consisted of slashing, burning and hoe weeding. Improved options were the use of glyphosate either alone or integrated with velvetbean. In the farmers' control, labour use was higher in yam and soybean than in cassava. In all crops, there was a 54 to 96% decrease in labour use as farmers switched from hoe weeding to chemical control. Including velvetbean in the improved management systems required an additional 45 person-hrha. Across all crops, chemical control reduced speargrass density, gave higher yields and gross benefits and had a lower cost of weed control than the farmer's control. Chemical control increased the net benefit over the farmers' control and gave higher benefit:cost ratios because of higher crop values and lower costs of weed control. Farmers preferred chemical control because of better crop performance and reduced labour use. The perceived high cost of herbicides was a disincentive for widespread adoption