The Anacardium species are native to tropical America [1] and have significant economic importance throughout the world, principally because of two of its natural products namely the cashew nut and apple [2]. The cashew represents Africa which provides 50% of the world production of raw cashew nuts, a great opportunity through the export of its nuts [3] [4].

Long time used in Côte d’Ivoire as a reforestation plant due to its rapid growth and its rusticity, the cashew tree was until the early 1990s exploited for its wood [5] [6]. But, since the beginning of the 2000s, cashew plantations have emerged gradually as income-generating speculation in front of cotton [5] [6]. Thus, the production of cashew has been very intensive in Côte d’Ivoire since 2015 with annual productions estimated at 700 thousand tons representing a rate of 21% of the world’s offer. Côte d’Ivoire is currently the world leading producer and exporter country of cashew. More than 250 thousand producers are concerned by cashew which represents the main source of income for approximately 1.5 million Ivorian people [6].

Despite the enormous potential for cashew revenue in Côte d’Ivoire, the cashew production is characterized not only by low yields, but also by a less competitive quality of nuts internationally [7]. Indeed, the production of cashew as other crops remained heavily dependent on climatic conditions [8]. The rainfall irregularities and temperature increasing made cashew tree cultivation vulnerable to undesirable organisms (weeds, insects, fungi, bacteria, etc.) and which were probably one cause of significant yields decrease and the depreciation of nut quality [9]. It had been also reported that the diversity of ecological regions combined with poor harvest and post-harvest practices are a major constraint to improve the quality of produced nuts [4] [10] [11]. For example, nutritional components degradation [12] [13] and contaminants such as mycotoxins occurrence in foods were strongly linked to poor agricultural practices [14] [15] probably by post-harvest metabolism mechanism [12]. Thus, the major source of food insecurity in Africa is post-harvest food loss. Pre- and post-harvest food losses in Africa are higher than the global average and impact more severely on already endangered livelihoods [16]. It has been estimated that at least 10% of the continent’s crop productivity was lost on and off farm [16]. In previous studies performed in African countries on horticultural crops, the levels of crops loss were up to 45.32% for tomato followed by mango (43.53%) and coffee (15.75%). Post-harvest loss ranging from 20% to 50% was recorded in between marketing and consumption [17] [18]. This is because most farmers do not have access to appropriate crops production technologies combined to erratic climatic conditions such as heavy rains, droughts and other related factors [19].

In Côte d’Ivoire, despite the measures taken to improve the quality of cashew nuts, it remains poor or classed acceptable [20] [21] because of the moisture levels often above the 10%, the standard of water content. In addition, the abusive use of pesticides occurred in the practices of farmers from several main regions of cashew production [22]. That could explain the Ivorian cashew nuts quality degradation [20] and an Out-turn average ranged between 46 and 48 lbs compared to 47 to 49 lbs in Benin and Nigeria and 50 to 52 lbs in Senegal and Guinea-Bissau respectively [4] [23]. Out-turn is mainly related to cashew nuts graining [21] [23], to physical and morphometric traits [24] [25] and to the defects of the nuts produced. Since poor harvest and post-harvest practices are a major obstacle to improve the quality of produced nuts [4] [10] [11], it appears very urgent for the Côte d’Ivoire to have sufficient information about these steps of cashew production system. Previous studies in this domain in Côte d’Ivoire and other African countries were rare. Those available in Côte d’Ivoire concerned essentially the genotypic screening of high-yield cashew nuts [21] and an evaluating of cashew pests [9]. The few data available on pre or postharvest practices concerned those reported from Ghana [19]. In this study focused on assessment of postharvest handling effects on quality of cashew nuts and kernels, it had been revealed that disparities in period of cashew fruits picking, nuts drying processing and duration as well as storage [19]. In comparison to those finding from Ghana, we hypothesized that the practices of farmers from Côte d’Ivoire may be more or less different. The farmers from East of Côte d’Ivoire could have significantly the same practices due to their geographical proximity with Ghana. But, farmers from the North of Côte d’Ivoire could have other practices as previously reported such as abundant pesticides uses in cashew production [22] similar to cotton production [26]. In this context, the present study focused on the description of pre and postharvest technologies of cashew nut represented a major step to collect sufficient information necessary to improve the cashew nuts quality and ensure the sustainability of this speculation in Côte d’Ivoire.

The present study focused on the agricultural practices of cashew nuts famers in Côte d’Ivoire through the three main regions of production namely Bondoukou, Mankono and Dabakala, which represent 40% of annual cashew nuts production according to Ivorian cashew regulation organism. Since pre or postharvest practices could influence the quality of crops [28] [29] [30], our study is thus justified. In addition, practices of cashew farmers could be also influenced by their culture and communities and the agricultural practices applied to local preponderant crops such as cotton in Mankono and cocoa in Bondoukou. Moreover, there was no scientific data available on the description of agricultural practices in cashew cultivation in Côte d’Ivoire and very few studies in this field from Africa countries producers were reported or published [19]. Finally, Côte d’Ivoire is the first cashew nuts producer and exporter in the world so the implementation of the basis of certification appeared inevitable in cashew sector. We thought that the improvement of cashew production process should involve firstly a best acknowledge of good agricultural practices. In this context, for the present study, three groups of variables have been followed namely the information on the plantations, the harvest and postharvest practices.

Concerning the typology of cashew plantations in Côte d’Ivoire, more than half of farmers adopted plants association which could be intermittent or annual. Crops frequently associated with cashew were yams, maize, peanuts, rice, cassava, cotton and millet. Previous studies have shown that crops cultivation associations or intercropping have interesting prospects such as soils fertility, control weeds in cashew plantation, avoiding malnutrition and the diversification of farm incomes [31] [32] [33]. Indeed, depending on soil and climatic conditions and local situations, annual crops like tapioca, pulses, turmeric, ginger, yam, maize, etc., can be grown as inter crops. Leguminous crops such as groundnuts, horse gram, cowpea and beans are very suitable for inter cropping [31]. However, farmers may pay attention to the inter-cropping practice because possible problems of competition between several speculations have been reported, with namely a low yield or low plants growth as consequences [31] [32] [33]. For example, inter-cropping could be practiced in the first few years (4 - 5 years) when there is sufficient space between crop rows, but tall growing inter-crops like certain varieties of sorghum and millet should not be encouraged between young cashews, as they provide too much shade [31]. In addition, farmers must avoid plants that may host pests and diseases of cashew. Indeed, it had been reported that abundance and diversity of key cashew insect pests and diseases were influenced by agroecological zones and subzones [34]. That could enhance the use of pesticides and probably explain the abundant use of pesticide by farmers from Mankono [22]. Indeed, farmers from Mankono were also producers of cotton so they tend to use the same pesticides in cashew cultivation. In addition, they were older with large plantations and the density of workers per hectare as observed during harvesting was low in Mankono compared to those from Bondoukou and Dabakala regions. These disparities could also explain the abnormally long time of nuts picking in Mankono where nearly half of farmers collected cashew nuts at least once a week. The consequences on the quality of cashew nuts were probably fungi proliferation and mycotoxins secretion [35] but also spoilage on the farm namely changes in nuts physical and biochemical properties [19] [35] [36]. It had been recommended not to pick the nuts exceed twice a day [19] [36]. This recommendation was moderately acted in Bondoukou and Dabakala regions, so there is an actual need to improve the cashew harvesting process in Côte d’Ivoire. The harvesting process should be improved on other aspects, namely the reduction of pesticides’ used by regular maintenance. Indeed, nearly all farmers from Mankono and Dabakala against only one-tenth of farmers from Bondoukou practiced chemical treatment of their farms during harvesting. Herbicides such as controversial glyphosate and 2,4-D were majors chemicals used [22] and that could affect the quality of cashew if the presence of their residues in cashew nuts exceeded the Maximum Residue Levels (MRLs). However, the use of fungicide in Mankono could be explained by the long delay of nuts picking since famers have observed molds proliferation. Other disparity in harvesting practice was the nuts sorting or not before drying. Most of farmers from Bondoukou adopted this practice, in contrast to Mankono where a significant number of farmers ignored it. The sorting was one possibility to improve cashew nuts quality because farmers could remove defective or immature nuts and avoid favorable conditions to mold colonization [35]. Indeed, a recent study in Nigeria, a West African county, revealed that eleven fungal species belonging to five species were isolated from the cashew nuts, with Aspergillusfavus,Rhizopus oryzae,and Fusarium oxysporum having the highest percentage occurrence of 50% [37]. Farmers from Mankono used fungicides probably to counteract mold proliferation since the nut picking delay was very long up to one week.

Concerning the post-harvest processing, our study focused on drying and storage process. Different dryers have been found, namely drying rack table, concrete floor and tarpaulins, the same dryers used in cocoa beans drying in Côte d’Ivoire [38]. In the study to evaluate the influence of fermentation and drying materials on the contamination of cocoa beans by ochratoxin A (OTA), it had been reported that the type of dryers did not affect OTA concentrations [38]. But, occurrence of aflatoxins in cashew nuts had been reported in Nigeria with concentration ranged between 0.1 - 6.8 and 29 - 33.78 ng·kg⁻¹ for cashew nuts and groundnuts, respectively and the values of aflatoxins concentrations could vary according to cashew origin [37]. Considering the possible contamination of cashew nuts by aflatoxins [37] [39] [40], it had been recommended that nuts drying should be done on hard ground, preferably, concrete floors and nuts should be spread thinly on the ground or should not exceed 20 kg/m² or a finger depth and must be turned constantly about twice to three times a day for uniform drying [19] [35] [36]. The duration of drying is also a factor which, if not adequate, could lead to contamination of nuts by aflatoxins. Our study revealed a risk of contamination in Bondoukou since more than 70% of farmers dried their nuts only for 2 days while it recommended 3 - 4 days [19] [36] or 5 - 7 days [35] to reach a moisture level of 10% - 12% or until the kernels rattle in the shell. However, the absence of sorting during the drying process in order to remove defective nuts in Mankono was an insufficiency because the presence of only one moldy nut could affect several nuts and thus decreased the quality. Finally, cashew nuts storage process has been investigated in our study and at least 50% of farmers stored their product during a duration varying from 1 to 6 months. Farmers from Mankono stored their products longer by using pesticides namely insecticides revealing risk to occurrence of their residues in cashew nuts.

This study described the cultivation practices of cashew nut producers and contributed to the establishment of a database on the determinants of the quality of nuts produced in Côte d’Ivoire. The present study showed real disparities in the techniques used by producers in Mankono, Dabakala and Bondoukou. In the Mankono area, pesticides were used extensively in cashew cultivation. The time taken to pick up the nuts was long and they were not sorted once picked up. This resulted in a high rate of defective nuts. The practices in Dabakala were similar to those observed in Mankono with the exception of the separation of defective nuts at the drying stage. Producers in the Bondoukou area had a relatively short drying time, while cashew nuts could be stored for a fairly long time. It is therefore necessary to assess the real impact of pre- and post-harvest practices in Côte d’Ivoire on cashew nut quality in order to improve its competitiveness and sustainability.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

We are really grateful to ANADER (“Agence National d’Appui au Développement Rural”) and COPABO (“Société Coopérative des Producteurs Agricoles de Bondoukou”) for its help in rural area.

Yao Stéphane KOFFI: Methodology, Supervision, Software, Formal Analysis, Resources, Data Retention, Research and acquisition of funding. James Halbin KOUADIO: Project Administration, Conceptualization, Methodology, Resources, Data Retention, Supervision, Writing original project, Research and acquisition of funding. Joseph SOYA: Methodology, Supervision.

The authors declare no conflicts of interest regarding the publication of this paper.

Stephane, K.Y., Halbin, K.J. and Joseph, S. (2021) Disparities in Agricultural Practices According to Cashew Nut Production Regions in Côte d’Ivoire and Probable Incidence on Nut Quality. Agricultural Sciences, 12, 1168-1183. https://doi.org/10.4236/as.2021.1210075