The effects of a Carbendazim-Mancozeb fungicidal mixture on microbial populations and some enzyme activities of three selected soils of Kwara State, Nigeria were studied. The soil dilution method was used to isolate bacteria, fungi, actinomycetes and some functional microbial groups from treated soils. Cultivation and enumeration of the soil microorganisms were made on different selective media. Assays for cellulases and pectinases in the treated soils were carried out. The populations of actinomycetes, bacteria and fungi were reduced significantly by the application of the fungicide. The fungicide applied at a concentration of 2.34mg/kg soil had a greater (p < 0.05) inhibitory effect than the recommended concentration of 1.67mg/kg soil. The populations of nitrogen fixers nitrifying bacteria and cellulolytic organisms were also significantly (p < 0.05.) reduced at the two concentrations. The fungicidal mixture equally lowered the cellulose and pectinase enzyme activities in soil significantly, with a return to normalcy by 60 days after treatment. A re-establishment of the soil microbial populations was observed by 21 days after treatment. It was concluded that the use of the Carbendazim-Mancozeb mixture should be with caution since it reduced the populations of ecologically important non-target organisms and that the recommended concentration should be adhered to.
Laboratory study was conducted to evaluate the effect of leaf extracts of five indigenous plant on conidia germination, growth and sporulation of Pseudoperenospora cubensis causing downy mildew disease of muskmelon. Extracts of five plant; mexican sunflower (Tithonia diversifolia), bush banana (Uvaria chamae), salt and oil tree (Cleistopholis patens), goat weed (Ageratum conyzoides) and African eggplant (Solanum macrocarpon) at Four concentrations (15, 30, 45 and 60%) were tested against the growth, conidial germination and sporulation of Pseudoperenospora cubensis in vitro.
Results show that all the plant extracts significantly inhibited conidia germination and radial growth compared to the control. The extracts had no significant (p≤0.05) effect on sporulation. The rate of inhibition of growth and conidia germination was concentration dependent being highest at 60% for the extracts. The extracts of Solanum macrocarpon was the most effective followed by Ageratum conyzoides, Cleistopholis patens and Uvaria chamea whileTithonia diversifolia caused the least inhibition of growth and conidia germination. At 15, 30, 45 and 60% concentrations growth of Pseudoperenospora cubensis on PDA modified with Solanum macrocqrponwere 3.79, 3.65, 3.33 and 2.87; and 4.25, 4.12, 3.92 and 3.89 for PDA modified with Tithonia diversifolia. Similarly, conidia germination percentages recorded at same concentration of extracts S. macrocarpon were 87, 85, 70 and 62% while that of T. diversifolia were 91, 87, 84 and 72%. The study shows that the plant extracts has the potential for inhibition of the pathogen.
This study evaluated the influence of phosphorus (P) application on the growth and yield of cowpea (Vigna unguiculata L) on two soil types in Ekiti State, Nigeria. The sites were Teaching and Research Farm, Ekiti State University, Ado-Ekiti, on a soil classified as Iwo series and a farm at Ikere-Ekiti on a soil derived from charnockite classified as Egbeda Series. The treatments consisted of 0, 20, 40 and 60 kgP ha-1 arranged in randomized complete block design with three replicates. The results indicated that P application significantly influenced growth of cowpea with maximum vine length, number of branches, number of leaves, number of nodules and dry matter yield of 97.4cm, 15.4, 26, 27.5, 32.4g plant-1 respectively. Application of 40kg P. ha-1 gave significantly (P<0.05) highest grain yield of 1583kg ha-1 while Ado-Ekiti soil seems to be the most suitable for cowpea production.Keyword: phosphorus, soil types, cowpea and grain yield.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.