Performance of Cowpea (Vigna unguiculata (L) Walp) as Influence by Different Weed Control Methods

A field study was conducted during the late planting season of 2013 at the Teaching and Research Farm of the Faculty of Agriculture and Veterinary Medicine, Imo State University, Owerri, to determine the effects of different methods of weed control on the growth and yield of cowpea. Different weed control methods (Weedy Check/Control Plot (T1WC1), Hand-Weeding at 20 and 40 Days after planting (DAP)( T2WC2), Hoe Weeding at 20DAP (T3WC3), Chemical Weeding at 20 DAP (T4WC4), Hoe Weeding at 20DAP + hand – weeding at 40DAP (T4WCs), Chemical Weeding at 20 DAP (T4WC6)) were compared for their efficiency to control various weed species in Owerri, Nigeria. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. Cowpea seeds (Ife brown) were collected from the Department of Crop Science and Biotechnology of Imo State University, Owerri and planted at a distance of 50cm x 50cm. The post emergence herbicides (fusilade forte) used for chemical weed control was bought at Imo State Agricultural Development Programme Owerri (Imo ADP). The parameters measured were; types of weeds and their relative abundance, plant height (cm), stem girth (cm), number of branches/plant, number of leaves per plant, leaf area (cm2), number of root nodules per plant, number of days to 50% flowering, plant biomass, number of pods per plant, number of pods per plot, pods weight per plot(g), 100 seed weight(g), pod yield (kg/ha), and seed yield (kg/ha) Predominant weed types observed in the cowpea plots were; Aspilia Africana, Euphorbia heterophylla, Imperata cylindrical, Talinum triangulare , cyperus esculentus and Tridax procumbens. Among different weed control methods, hoe weeding at 20DAP + hand weeding at 40DAP gave seed yield of 47.77kg/ha. This treatment (hoe weeding at 20DAP + hand weed at 40DAP) out performed others in terms of 100 seed weight (94.10g) which significantly different (P<0.05) from the records of the other treatments. On the basis of these results, Maximum seed yield 47.77kg/ha of cowpea (Ife brown)) was obtained with the application of hoe weeding at 20DAP + hand weeding at 40DAP. Keywords: weed biomass, herbicides, weed control, owerri, cowpe

Biocidal effects of dennettia tripetala, zingiber officinale and benlate on seedborne fungal pathogen (fusarium moniliforme) of watermelon (citrullus lanatus) varieties.

This study was carried out to investigate the effect of plant extracts, African pepper fruit (Dennettia tripetala) and Ginger (Zingiber officinale) on seed borne fungal pathogens of Watermelon (Citrullus lanatas) seeds. Watermelon seeds were extracted for seed health test using blotter paper method. The antifungal effects of ethanol and acetone extracts of the two plant extracts and synthetic fungicide were studied under in- vitro experiment against the seed borne fungal pathogen of Watermelon at 0%, 50% and 75%. It was a 3x3 factorial experiment at 5% Probability level laid out in a Completely Randomized Design experiment with three replications Ninety percent germination was obtained in the germination and seed health test of Watermelon seeds. Seed borne fungal pathogen (Aspergillus spp. and Fusarium spp.) were identified. The potential of these organisms for pathogenicity were tested using Kock’s postulate. The result of the pathogenicity test showed that Fusarium spp. was pathogenic. All plant extracts and Benlate inhibited the fungus (Fusarium moniliforme) in culture. The inhibition was also greater as concentration increased from 50% to 75%.  It was also observed that ethanol extraction solvent did better than acetone. Generally, Dennettia tripetala extract performed better than Zingiber officinale. It could therefore be recommended that the two plant extracts used in this investigation which were very effective in the control of Fusarium moniliforme of watermelon could be an alternative to the synthetic fungicide. It could also be suggested that further studies be carried out to isolate, identify, characterize and standardize the bioactive components of these phytochemicals in a bid to commercializing their production