Background and Objective: Cashew tree cultivation is currently booming in Togo and their nuts are Togo's fourth most important agricultural export.A study was initiated to draw up an inventory of cashew fungal diseases and determine their epidemiological parameters.Materials and Methods: Thirty two cashew orchards were surveyed, with eight orchards per prefecture.Twenty trees per orchard were randomly selected along the diagonals and inspected.Incidence was defined as the proportion of cashew trees showing symptoms of a fungal disease.Severity was assessed on an arbitrary five-grade scale by assigning quality values to infected organs.The severity index was determined by a mathematical formula.Prevalence was the proportion of localities affected by a fungal disease per prefecture.Results: Eight fungal diseases were inventoried, including anthracnose, black rust, bud dieback, yellow leaf spot, pestalotiosis, powdery mildew, gummosis and ramularia.Incidence and severity index were 61.09 and 36.56%,respectively for pestalotiosis, 38.12 and 20.16% for leaf anthracnose, 35.62 and 14.84% for yellow leaf spot and 30.47 and 20.46% for bud dieback.The prevalence of anthracnose leaf spot was the most widespread (96.88%), followed by yellow leaf spot (84.38%), pestalotiosis (84.38%) and black rust (81.25%).Conclusion: Because of the impact of these fungal diseases, it would be necessary to use phytosanitary products, improve agricultural practices and introduce more resistant cashew cultivars for new cashew orchards.
Background and Objective: Maize, a vital cereal crop globally, faces challenges from foliar diseases like common rust, impacting yield and quality.This study assesses the efficacy of sodium metabisulphite salt (SMBS) in controlling common maize rust caused by Puccinia sorghi and its impact on Wistar rat health.It aims to offer insights into SMBS as a sustainable alternative to chemical fungicides by evaluating disease incidence and monitoring rat health post-consumption.Materials and Methods: A study at the Institute of Agricultural Research and Training, Obafemi Awolowo University, Ibadan, assessed SMBS for maize disease management and safety.Two maize varieties, ART/98/SW5-OB and T2BR-ELDB, received SMBS treatments (10 and 15 g/L) at different growth stages in a Randomized Complete Block Design with three replications.Disease incidence, severity and agronomic traits were analysed using ANOVA and Duncan's Multiple Range Test at p<0.05.Results: The results indicated that SMBS application significantly promoted plant growth, as evidenced by increased plant height, leaf number and leaf area with a significant reduction in incidence and severity of common rust disease in maize plants studied, highlighting its potential as a protective agent against fungal infections in crops.However, variations in the responses of different maize varieties to SMBS were observed.The acute toxicity of SMBS was also assessed on Wistar rats as they were exposed to varying doses of SMBS through the consumption of maize leaves and the powdered form.The results demonstrated that SMBS did not cause any significant adverse reactions and death in the rats at the tested doses, indicating a relatively low acute toxicity in this animal model. Conclusion:The study confirms SMBS as a promising dual-purpose agent for maize disease control and growth promotion, demonstrating its safety and efficacy, thus advancing sustainable agricultural practices.
Background and Objective:The Bacillus species are proven biological control agents, present in nature, though can be cultured.In this study the Bacillus species were evaluated on the field for the management of root knot nematode, Meloidogyne incognita, a pest of pepper.Materials and Methods: The field experiment was a 2×7 factorial, fitted into randomized complete block design.There were two pepper varieties, seven treatments replicated four times and inoculated with 5,000 juveniles of M. incognita at two weeks after transplanting.Data were collected on nematodes and on the growth and yield of pepper.Data were analyzed using analysis of variance and means were compared using Fisher's Least Significant Difference at 5% probability level.Results: The tallest pepper (53.00 cm) was from pepper treated with mixture of B. cereus and B. thuringiensis while the shortest (16.33 cm) was from the control plot.The highest fruit yield (9.0 g) was produced by pepper treated with B. thuringiensis while the control had the lowest (1.67 g).Nematode populations were significantly reduced in Bacillus treated soil (146.17 in 250 mL soil) compared to control (947.38 in 250 mL soil).Conclusion: This study concluded that the application of Bacillus species reduced soil nematode population significantly and increased fruit yield of pepper.
Background and Objective: Alternaria solani is responsible for causing early blight, leaf spot, collar rot, fruit rot and stem canker diseases in solanaceous crops and is very difficult to control.Several management strategies are employed but chemical fungicides are most effective.However, due to their established negative consequences, much greener and eco-friendly options are needed.Nanotechnology could offer new approaches for solving this problem and the present study was carried out to explore the fungicidal activity of twelve nanoparticles against the mycelial inhibition of Alternaria solani. Materials and Methods:The comparative inhibitory effect of twelve Nanoparticles (NPs) viz., Cobalt ferrite (CoFe 2 O 4 ), Elemental copper (Cu -), Ferric oxide (Fe 2 O 3 ), Nickel ferrite (NiFe 2 O 4 ), Nickel peroxide (NiO 2 ), Polyamelene (PANI), Polyanelene+ferrite (P600), Tin oxide (SnO 2 ), Titanium oxide (TiO 2 ), Zinc ferrite (ZnFe 2 O 4 ), Zinc oxide (ZnO), Zinc peroxide (ZnO 2 ) and Salicylic acid (SA) were evaluated in vitro against Alternaria solani.All the data were processed by using Analysis of Variance (ANOVA) and Rsoftware at (p<0.05).Results: In vitro, screening of NPs and SA at 5, 10, 15, 20 and 25 µg/mL revealed substantial variability to inhibit the mycelial growth of A. solani.In general, the NPs which caused significant inhibition in fungal growth, their effectiveness increased with increase in the concentrations.Among the NPs, zinc peroxide (20 µg/mL), salicylic acid (20 µg/mL), zinc oxide (20 µg/mL), elemental copper (20 µg/mL), nickel peroxide (25 µg/mL) and ferric oxide (25 µg/mL) caused the 100% inhibition in the mycelia growth of A. solani.Conclusion: This is the first study on the fungicidal effects of nano-zinc peroxide on A. solani.However, the mechanism involved in the fungicidal activity and toxicological studies are required to be confirmed.
Background and Objective: Tomato yellow leaf curl disease (TYLCD), caused by tomato yellow leaf curl virus (TYLCV), was first reported in Mauritius in 2009.This study reports on the status regarding the genetic identity of TYLCV isolates in Mauritius, based on data collected in 2015-2018. Materials and Methods:The TYLCV-infected plants showing clear symptoms were collected from 21 localities around the island.The presence of TYLCV was confirmed using standard TAS-ELISA tests and triplicates of each leaf sample were subject to DNA extraction followed by PCR amplification of part of the C1 replication-associated gene and the PCR products were sequenced and edited and subjected to a similarity search using the BLASTN tool.The sequences were then aligned using MEGA11 software and phylogenetic trees were generated using the UPGMA method with 1000 bootstrap values.Results: This study revealed 12 genetically distinct isolates of TYLCV, with 4 of them seemingly representing the ancestral TYLCV-IL lineage, 6 of them representing variants or recombinants of the ancestral lineage and 2 isolates which could potentially represent new strains.This study shows that, over a period of 9 years, with the continued cultivation of susceptible tomato varieties and the presence of alternate hosts, the original 2009 TYLCV isolate underwent multiple mutation events that eventually resulted in the appearance of two possibly novel strains.Conclusion: The TYLCV has shown a very rapid rate of mutation on Mauritius Island, possibly evolving into new strains and now constitutes an important economic threat to local tomato production.
Background and Objective: Leaf blight incited by Phytophthora colocasiae has been a major challenge impacting on yield and commercialization of taro (Colocasia esculenta (L.) Schott) in Nigeria since 2009.This study evaluated in vitro, the efficacy of selected plant extracts against the causal pathogen.Materials and Methods: Four botanical extracts: Azadirachta indica A. Juss.Eucalyptus camaldulensis Dehn, Senna alata L. and Tithonia diversifolia (Hemsley) A. Gray were tested in vitro for their fungi toxic effects on radial growth and mycelia dry weight of the pathogen at 5, 10 and 20 mg/mL of each extract.Ridomil (0.67 mg/mL) and zero treatment were set along tests and treatments were replicated thrice in a Completely Randomized Design.Data were subjected to analysis of variance at a 95% confidence interval using the SPSS package and significant differences among means were compared using Duncan's Multiple Range Test (DMRT).Results: All the extracts exhibited significantly varying degrees of inhibition in the radial growth and mycelia dry weight tests.Percentage inhibition increased as the concentration increased.Azadirachta indica and S. alata extracts at 20 mg/mL inhibit 100 and 97.13% radial growth, respectively and were significantly (p<0.05)superior to 40.00 and 31.81%caused by T. diversifolia and E. camaldulensis, respectively.Complete (100%) inhibition of mycelia dry weight was obtained with S. alata and T. diversifolia extracts at all the selected concentrations while A. indica and E. camaldulensis showed high inhibition at some concentrations.Conclusion: These extracts have strong inhibitory effects against P. colocasiae and are comparable to the synthetic fungicide Ridomil, therefore, their exploration in the management of TLB is strongly advocated.
