Journal of Agriculture and Ecology Research International

Aims: This study aimed at demonstrating the ability of a mold species, isolated from a rice farm agricultural soil, chronically treated with glyphosate herbicide, to degrade glyphosate and to compare different evaluation methods of biodegradation.

Study Design: A completely randomized design of a factorial experiment was used.

Place and Duration of Study:    The study was conducted at the Department of Microbiology, University of Calabar, Nigeria between February and April.

Methodology: Molds were isolated from nine rice agricultural soil samples using potato dextrose agar. The molds were screened for glyphosate degradation using different media to determine their requirement for supplementation or not at all. A completely randomized design of a factorial experiment involving 3 factors at 3 levels each, with three replications, was adopted for glyphosate degradation studies. Degradation was monitored by dehydrogenase activity, carbon dioxide evolution, pH changes, fungal dry weight and residual glyphosate determination. A comparative evaluation of the different methods was made using multivariate statistics.

Results: The mold, identified as Trichoderma asperellum strain JK-28, was incapable of using glyphosate as sole sources of phosphorus and nitrogen and so required nutrient supplementation. Largest significant correlation between dependent variables (P < .001; r = - 779) occurred between dehydrogenase activity and fungal dry weight while the lowest was between residual glyphosate and fungal dry weight. Residual glyphosate and pH had negative correlations with other dependent variables. Principal component analysis extracted only one component with a cumulative variance of 70%. Multivariate analysis of variance (three-way MANOVA) of data, interpreted from the Pillai’s Trace test, was significant at P <.001 for the main, two- and three-way interactions.

Conclusion: Trichoderma asperellum strain JK-28 could degrade glyphosate using it as sole carbon source but with nutrient supplementation. Residual glyphosate determination is recommended as most reliable method for evaluating organic pollutant biodegradation.

Aims: To study the effects of mine tailings on the growth and yield of two genotypes of common bean (Phaseolus vulgaris L.).

Study Design: The experiment was laid in a Randomized Complete Block Design (RCBD) with four treatments, two blocks and each block was replicated three times.

Place and Duration of Study: Botanical Garden, Department of Plant Science and Biotechnology University of Jos, Plateau State, Nigeria during the rainy season in a field experiment in 2014.

Methodology: The mine tailings combinations include four different additions mine tailings soil {(T₀) 0 kg as control, (T₁) 2 kg, (T₂) 3 kg, (T₃) 4 kg} and the respective mine tailings soils were added to 6.3 kg of normal soil. Two common bean accessions were used (Cranberry-G1 and Pinto-G2), which gave the total of eight treatment combinations (T₀G₁, T₀G₂, T₁G₁, T₁G₂, T₂G₁, T₂G₂, T₃G₁, T₃G₂).

Results: The control recorded significant higher mean plant height (cm), number of leaves and number of trifoliate leaves, number of pods and number of seeds per pod in both genotypes for all the different weeks after planting (WAP). A significant decrease in plant height, number of trifoliate leaves, number of leaves per plant, number of pods and number of seeds per pod in both genotypes were observed with increased levels of mine tailings. There was a significant increase in time to 50% flower and 50% pod production (P = 0.01) over the control which increased with increasing levels of mine tailings. The genotypes exhibited no significant difference (P = 0.05) for most traits accessed, except for number of pod per plant. It is evident from the findings that Cranberry is more tolerant to heavy metals contamination in soil, perhaps may be more suitable for planting in such mining soils.

Conclusion: The study showed that inclusion of mine tailings had detrimental effect on both the growth and yield of common bean.

Oilseed plant, Brassica napus L. seedlings grown in hydroponic condition with different concentrations of Pb were treated with salicylic acid (SA) to investigate the role of exogenous salicylic acid in alleviating lead toxicity on biochemical and physiological activities of the plant. The results showed that application of different concentrations of Pb increased soluble sugars and reduced carbohydrate levels significantly in roots and shoots of the plants. The stress induced by application of Pb triggered significant inhibitory effects on growth and chlorophyll synthesis induced on the production of protein and proline and enhanced the levels of antioxidant activity. Salicylic acid (SA) treated plants showed alleviation increasing total dry mass, leaf area, shoot and root length as well as leaf total chlorophyll content in responses to Pb stress. Results revealed the importance of salicylic acid (SA) activity in enabling plants to reduce the soluble sugars and increase of insoluble sugar in heavy -metal-stressed plants. The content of proline and proteins were also reduced in plants were treated with salicylic acid. Our data provide evidence that salicylic acid treatment decreased the activity of antioxidant enzymes in plants were exposed to different levels of Pb.

Existing literature affirms the importance of agricultural technology adoption on productivity, income and livelihood outcomes. Evidences subsist on the adoption of improved cassava varieties (ICVs) in Nigeria but little is known about its impact among the farmers. We used data from a survey conducted by International Institute of Tropical Agriculture (IITA) to explore this research gap.  Propensity Score Matching and Heckman’s two-stage model were the analytical tools.  Given an estimated poverty line of (₦21717.53); 52.0% of the farmers were poor.  We found that 75.6% of the respondents are adopters of ICVs. Primary occupation of household head and total non-production asset of farmers were key determinants for adoption.  Adoption of improved cassava variety has positive effect on farmers’ productivity and poverty reduction. The Average Treatment Effect on the Treated (ATT) for productivity increased by 70 percent among ICVs farmers. Income was also higher among the adopters than the non- adopters by ₦43463.77. In the same vein, the income of the adopters increased by 17%. Furthermore, adopters of ICVs have the probability of reducing poverty headcount by 20%. The empirical results suggest that improved agricultural innovation adoption can play a key role in strengthening and impacting agricultural productivity of smallholder farmers for increased income generation and food security.

Weeds are the most prominent of all rice biotic stresses across all the ecologies in terms of yield reduction and increased cost of production. Weed control is therefore one of the most important and suggestive practices for potential rice production. Based on the above, field trials were carried out during 2017/2018 dry season at the Teaching and Research Fadama farm of the Kebbi State University of Science and Technology located at Jega (Latitude 12º21ˈN; Longitude 4º36ˈE) and that of Usmanu Danfodiyo University Sokoto located at Kwalkwalawa (Latitude 13⁰ 01ˈN, Longitude 5º09ˈE) to study the correlation between yield and selected parameters of some rice varieties grown in an integrated weed management (IWM) system. Both locations lie within the Sudan Savanna ecological zone of Nigeria. The experiment was done between December, 2017 and August, 2018. The treatments consisted of six (6) weed management options (Solarization/Orizo-plus (3WAT)/Hoe-weeding (6WAT), Round-up/Orizo-plus(at 3WAT)/Hoe-weeding (6WAT), Solarization/Hoe-weeding (3WAT)/Hoe-weeding (6WAT), Round-up/Hoe-weeding (3WAT)/Hoe-weeding(6WAT), Weedy-check and Weed-free) and three (3) rice varieties (Jamila, Faro 44 and Faro 57). The factorial combinations of the treatments were laid out in a randomized complete block design (RCBD) with split-plot arrangement, replicated three times. Weed management options formed the main plots while rice varieties were assigned to the sub-plots. Based on the results of this study, it could be concluded that high weed density in rice field causes poor rice growth and reduces grain yield (r=-0.757). Also, increase in number of leaves, number of tillers, leaf area index, percent productive tillers, length of panicle, weight of panicle and 1000-grain weight resulted to increased grain yield. Therefore, factors that encourage the performance of those parameters can be explored for high rice grain yield.