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In August 2020, a disease with symptoms identical to red rust caused by Cephaleuros virescens was found in orchards of mangoes besides orchards of Anacardium surveyed in Maroua and Garoua (Cameroon). The objective of this research was to study this disease with characterizing its causal organism using morphological methods. Mango leaves exhibiting clear symptoms of red rust with pathogen somatic and reproductive structures were used for morphological characterization and identification of the causal pathogen. Leaves were collected based on the symptoms, size and number of lesions associated. The survey results indicate that orange coloured,  small circular lesions were found on the upper leaf surfaces and coalescing in midrib were observed. Circular lesions on the leaves were of varied diameter from 1 to 5 mm with an average of 1.6 (coefficient of variation 34%). Among symptomatic leaves showing lesions, 60% were exhibiting lesions smaller than 2 mm in diameter.  The length and width of sporangiophores and sporangia were 237.62 - 4645.85 × 15.5 μm and 20.6 - 41.32 × 20.6 μm, respectively. Based on the symptoms observed and microscopic morphological studies, the recovered pathogen was identified as Cephaleuros virescens. This is the first report of algal leaf disease on M. indica in Cameroon.

Okra (Abelmoschus esculentus) is one of the main plants of high nutritional importance cultivated in Cameroon. However, its production is compromised by many constraints including the presence of insect pests, which are responsible for losses in the farms. The present study was carried out on the campus of the University of Yaoundé I. Its objective was to evaluate the insecticidal potential of Jatropha curcas seed extracts on the insect pests of okra. Two varieties of okra (Clemson and Hire) were used. Five treatments (T0: control, T +: Lamida gold 90EC insecticide, T-EAQ: treatment with the aqueous extract of J. curcas seeds, T-EAC: treatment with acetone extract of J. curcas seeds, T-E EAE: treatment with ethyl acetate extract of J. curcas seeds) were used in a completely randomized block design with three repetitions. Growth parameters, the number of insects, severity of phyllophages and fruit yield were evaluated. The results showed that a treatment and varietal effect was observed statistically significant on all growth parameters. The pests identified were: Aphis gossypii, Cheilomenes sp, Dydercus spp., Nisotra spp., Podagrica spp., Zonocerus variegatus. Aqueous and organic extracts of Jatropha curcas seeds were effective as Lamida gold insecticide against phyllophages in compared to the control. The best yield was obtained in T-EAQ treatment (9945.45), followed by T+ (8917.31), T-EAE (6712.9) and T-EAC (6149.9) compared to control T0 (4791.3). Variety V2, although having a susceptibility to insect attack, presented the highest yield (7158.9 kg/ha) compared to (6503.78kg/ha) for V1. Aqueous and organic extracts of J. curcas seeds appear to be a promising avenue in the integrated control of okra pests. Therefore, they can be valorized.

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