ABSTRACT
The impact of invasive species on biodiversity, food security and economy is increasingly noticeable in various regions of the globe as a consequence of climate change. Yet, there is limited research on how climate change affects the distribution of the invasive Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera:Liviidae) in Ghana. Using maxnet package to fit the Maxent model in R software, we answered the following questions; (i) what are the main drivers for D. citri distribution, (ii) what are the D. citri-specific habitat requirements and (iii) how well do the risk maps fit with what we know to be correctly based on the available evidence?. We found that temperature seasonality (Bio04), mean temperature of warmest quarter (Bio10), precipitation of driest quarter (Bio17), moderate resolution imaging spectroradiometer land cover and precipitation seasonality (Bio15), were the most important drivers of D. citri distribution. The results follow the known distribution records of the pest with potential expansion of habitat suitability in the future. Because many invasive species, including D. citri, can adapt to the changing climates, our findings can serve as a guide for surveillance, tracking and prevention of D. citri spread in Ghana.
ABSTRACT
Mango anthracnose disease (MAD) is a destructive disease of mangoes, with estimated yield losses of up to 100% in unmanaged plantations. Several strains that constitute Colletotrichum complexes are implicated in MAD worldwide. All mangoes grown for commercial purposes are susceptible, and a resistant cultivar for all strains is not presently available on the market. The infection can widely spread before being detected since the disease is invincible until after a protracted latent period. The detection of multiple strains of the pathogen in Mexico, Brazil, and China has prompted a significant increase in research on the disease. Synthetic pesticide application is the primary management technique used to manage the disease. However, newly observed declines in anthracnose susceptibility to many fungicides highlight the need for more environmentally friendly approaches. Recent progress in understanding the host range, molecular and phenotypic characterization, and susceptibility of the disease in several mango cultivars is discussed in this review. It provides updates on the mode of transmission, infection biology and contemporary management strategies. We suggest an integrated and ecologically sound approach to managing MAD.
ABSTRACT
Synthetic fungicides are necessary evil in crop production, their usage cannot be neglected or abandoned but must be alternated/supplemented with other control measures such as cultural, host resistance and biocontrol methods to reduce their detrimental effect on the environment and living organisms. A bioproduct (wood vinegar) was evaluated against oil palm seedling pathogens at CSIR-Oil Palm Research Institute, Kusi at different concentrations and compared with an inorganic fungicide at the manufacturer's recommended dosage. Disease pathogens were isolated from collected diseased leaf samples and pure cultures were established on cPDA. PDA was amended with wood vinegar ranging from 0 to 3.35% and 0.1%v/v of carbendazim as a positive control. Daily colony growth was measured in two diagonal lengths and averages of day 6 and day 7 were used to calculate the inhibition percentage for both pathogens. 11 mm/day was the lowest average growth rate recorded for 2.68% v/v of wood vinegar and 14.17 mm/day on control plate of Curvularia species. There was no significant difference between 0.1%v/v carbendazim, 2.68 and 3.35% v/v against Curvularia species whilst significantly, there was difference between 0.1%v/v carbendazim and 2.68 and 3.35%v/v of wood vinegar against Pestalotiopsis species.
