ABSTRACT
Background and aim: Citrus production represents an important activity for the national economy and a source of income for farmers in Benin. However, fungal diseases are a major constraint to production intensification. The aim of this study is to assess farmers' perceptions on citrus fungal diseases in production areas in Benin. Methods: A survey was conducted among 417 farmers between July and December 2021 in four major citrus-producing agro-ecological zones (zones V, VI, VII and VIII) to collect their perceptions, knowledge and management practices of citrus fungal diseases. Results: Farmers reported that fungal diseases are one of the main constraints to citrus production, including black spot, anthracnose, brown rot, sooty mold and fruit rot. Among them, black spot disease is the most severe, causing damage to production. According to farmers, symptoms appear on fruit after fruit set, with a very remarkable presence and high incidence at maturity. Although farmers are most of times aware of the damage caused by fungal diseases with adverse consequences on their income, they have a poor knowledge of appropriate phytosanitary products to manage these diseases. Indeed, the majority of farmers (>60 %) use chemical insecticides, which they reported to be ineffective against citrus fungal diseases. Although chemical insecticides are their only recourse, almost 40 % use nothing to control these diseases. Farmers stated that climatic variability is a factor favoring the development of diseases, leading to reduced production. Conclusions: Among the several citrus fungal diseases, black spot is perceived as the most damaging, causing greater yield losses under favorable conditions, coupled with an almost total absence of appropriate control methods. This study contributes to the reorganization of the citrus industry and to decision-making on capacity building for farmers in terms of orchard pest protection, in order to guarantee better production of marketable and exportable fruit.
ABSTRACT
Tomato is one of the most appreciated vegetables in the world. Predicting its yield and optimizing its culture is important for global food security. This paper addresses the challenge of finding optimum climatic values for a high tomato yield. The Frequent Pattern Growth (FPG) algorithm was considered to establish the associations between six climate variables: minimum and maximum temperatures, maximum humidity, sunshine (Sun), rainfall, and evapotranspiration (ET), collected over 26 years in the three agro-ecological Zones of Benin. Monthly climate data were aggregated with yield data over the same period. After aggregation, the data were transformed into 'low', 'medium', and 'high' attributes using the threshold values defined. Then, the rules were generated using the minimum support set to 0.2 and the confidence to 0.8. Only the rules with the consequence 'high yield' were screened. The best yield patterns were observed in the Guinean Zone, followed by the Sudanian. The results indicated that high tomato yield was associated with low ET in all areas considered. Minimum and maximum temperatures, maximum humidity, and Sun were medium in every Zone. Moreover, rainfall was high in the Sudanian Zone, unlike the other regions where it remained medium. These results are useful in assessing climate variability's impact on tomato production. Thus, they can help farmers make informed decisions on cultivation practices to optimize production in a changing environment. In addition, the findings of this study can be considered in other regions and adapted to other crops.
Subject(s)
Solanum lycopersicum , Benin , Africa, Western , Humidity , TemperatureABSTRACT
Spodoptera frugiperda was first reported in Africa in 2016 and has since become a serious threat to maize/cereal production on the continent. Current control of the pest relies on synthetic chemical insecticides, which can negatively impact the environment and promote the development of resistance when used indiscriminately. Therefore, great attention is being paid to the development of safer alternatives. In this study, several biorational products and a semi-synthetic insecticide were evaluated. Two household soaps ("Palmida" and "Koto") and a detergent ("So Klin") were first tested for their efficacy against the larvae under laboratory conditions. Then, the efficacy of the most effective soap was evaluated in field conditions, along with PlantNeem (neem oil), Dezone (diatomaceous earth), and Emacot 19 EC (emamectin benzoate), in two districts, N'Dali and Adjohoun, located, respectively, in northern and southern Benin. The soaps and the detergent were highly toxic t second-instar larvae with 24 h lethal concentrations (LC50) of 0.46%, 0.44%, and 0.37% for So Klin, Koto, and Palmida, respectively. In field conditions, the biorational insecticides produced similar or better control than Emacot 19 EC. However, the highest maize grain yields of 7387 and 5308 kg/ha were recorded, respectively, with Dezone (N'Dali) and Emacot 19 EC (Adjohoun). A cost-benefit analysis showed that, compared to an untreated control, profits increased by up to 90% with the biorational insecticides and 166% with Emacot 19 EC. Therefore, the use of Palmida soap at 0.5% concentration, neem oil at 4.5 L/ha, and Dezone at 7.5 kg/ha could provide an effective, environmentally friendly, and sustainable management of S. frugiperda in maize.
