Incidence of seedling blight disease of Raphia palm (Raphia hookeri Mann and Wendl.), the disease agent and its phytotoxic effect in the seedlings and nutrient property of soil at the Nifor sub-station, Onuebum, Bayelsa State

A study of the incidence of seedling blight disease among Raphia hookeri palm seedlings in the Nigerian Institute for Oil Palm Research, Raphia Substation, Onuebum, Bayelsa State, Nigeria was carried out to determine the causal agent of the disease, phytotoxic- effect of the causal agent on the seedlings and assess the nutrient status of the R. hookeri seedling blocks. The disease incidence was 5%. Advanced stage of seedling blight was characterized by the lamina of the leaflets becoming fragile and gradually falling off, leaving tattered leaflets. Overall soil fertility was adequate, although the soil was poorly drained. Pathogenicity test and molecular analysis revealed that Diaporthe sp. was responsible for the disease. Results also showed that Diaporthe sp. likely released toxic substances which damaged the photosynthetic layer of the leaf tissues. This is the first report of Diaporthe sp. causing seedling blight in R. hookeri. Symptoms of the disease were similar to those caused by Glomerella cingulata usually seen in the rainy season. A study of the incidence of G. cingulata and Diaporthe sp in the seedling blight of R. hookeri during both rainy and dry seasons is suggested. Improved soil fertility might contribute towards the successful management of seedling blight disease caused by Diaporthe sp

Incidence of seedling blight disease of Raphia palm (Raphia hookeri Mann and Wendl.), the disease agent and its phytotoxic effect in the seedlings and nutrient property of soil at the Nifor Sub-Station, Onuebum, Bayelsa State

A study of the incidence of seedling blight disease among Raphia hookeri palm seedlings in the Nigerian Institute for Oil Palm Research, Raphia Substation, Onuebum, Bayelsa State, Nigeria was carried out to determine the causal agent of the disease, phytotoxic- effect of the causal agent on the seedlings and assess the nutrient status of the R. hookeri seedling blocks. The disease incidence was 5%. Advanced stage of seedling blight was characterized by the lamina of the leaflets becoming fragile and gradually falling off, leaving tattered leaflets. Overall soil fertility was adequate, although the soil was poorly drained. Pathogenicity test and molecular analysis revealed that Diaporthe sp. was responsible for the disease. Results also showed that Diaporthe sp. likely released toxic substances which damaged the photosynthetic layer of the leaf tissues. This is the first report of Diaporthe sp. causing seedling blight in R. hookeri. Symptoms of the disease were similar to those caused by Glomerella cingulata usually seen in the rainy season. A study of the incidence of G. cingulata and Diaporthe sp in the seedling blight of R. hookeri during both rainy and dry seasons is suggested. Improved soil fertility might contribute towards the successful management of seedling blight disease caused by Diaporthe sp

Fungi Associated with the Postharvest Fungal Deterioration of Shea Nuts and Kernels

Abstract The preliminary investigation into the postharvest fungal deterioration of Shea nuts and kernels with the aim to investigate and assess the impact of the fungi on the postharvest deterioration of Shea nuts and stored Shea kernels revealed four types of postharvest deterioration which are nut cracks, kernels discoloration, nuts discoloration and kernel deterioration. The major causes of the postharvest deterioration of Shea nuts are mainly as a result of cracks in the nut, insect's larvae and microorganisms. The microorganisms isolated from the postharvest fungal deterioration of Shea kernels using the serial plate dilution techniques, revealed the presence of four genera of microorganisms such as Aspergillus, Mucor Phoma and Fusarium spp while two genera of microorganisms namely Aspergillus and Xylaria were isolated from the Shea kernels and nuts respectively. The prevalence of these fungi on the deteriorated Shea kernels was as a result of favourable pH of between 5.8 and 6.0 and moisture content of between 4.76% and 10%. The possible source of these microbial contaminants on the Shea nuts and kernels was through cracks in the Shea nuts, insect's larvae, contaminants from the environment and storage conditions. The results of the pathogenicity test with these isolates showed that Aspergillus niger, A. flavus and A. persii were more pathogenic on the Shea kernels than the other isolates. These pathogens caused loss of viability of Shea nuts, tainting, colour deterioration and rot of the kernels which could result in poor quality of the processed Shea butter. Due to the economic importance of the Shea nut and kernels which include it uses for Shea butter and Shea oil production, it is important to development an appropriate cost effective techniques for storing the Shea kernels against postharvest fungal deterioration so as to harness its full economic benefits