Before assessing the project’s impact on improving producers’ income, interviews revealed that the project had influenced several other aspects of producers’ lives, which in turn directly or indirectly contributed to increased income. Specifically, the project fostered a positive shift in producers’ attitudes by raising their awareness of mango quality and its significance for export. Producers also came to appreciate the utility and effectiveness of fruit fly control products in achieving these outcomes.

Moreover, through the implementation of pest trapping systems, the project enabled many producers to identify fruit flies. According to the 2015 baseline survey (Doumbia et al.), only about 20% of producers were previously able to identify one of the main pests of mangoes in the region, namely the fruit fly. Interview results indicate that this trend has now reversed, with the majority of producers currently able to identify fruit flies—an important milestone in the organization of pest management efforts.

Based on interview findings, a further major impact of the project, attributable to the use of its products, is the lengthening of the mango harvest season. Previously limited to a maximum of approximately two weeks, the mango season now extends to six or even seven weeks. This substantial extension enables the collection and sale of a significantly larger volume of mangoes. Additionally, many producers reported that the project’s interventions have allowed them to retain healthy fruit on the trees for longer periods. As a result, when these mangoes are harvested and brought to market later in the season, they command higher prices compared to the initial harvest period.

The year-to-year decrease in the number of interceptions stands out as one of the project’s principal outcomes, although this trend does experience occasional reversals in certain years ( Table 1 ). The overall decline in interceptions should be analyzed in conjunction with the substantial financial investments made by the State in the form of subsidies.

Source: Report on the 2018 Mango Campaign Assessment (DPVCQ).

A combination of several factors—including increased producer knowledge and improved practices, an extended mango harvest season, and a reduction in the number of interceptions—has led to a significant rise in producers’ income over the past three campaigns within the project area. For example, state intervention through the distribution of “succès appât” contributed to a decline in interceptions. The success of this treatment distribution was such that exporters were able to provide bonuses to producers.

When queried about how they utilize their earnings, producers report, in order of decreasing importance:

Following our analysis of the ways in which the project has enhanced producers’ income, we deemed it pertinent to examine additional factors, unrelated to the project, that have also played a role in this outcome.

Interview findings highlight three principal factors in this regard: the proactive engagement and support of exporters in facilitating project activities, the motivational effect of pricing incentives, and the active participation of some producers in the certification process.

Producer engagement in supporting project activities has been evidenced by the establishment of producer loyalty to a specific exporter, facilitated through crop advances—in other words, by pre-financing via the provision of treatment products. This arrangement enables exporters to gain a comprehensive understanding of the production environment of their associated producers, allowing them to intervene as needed, either by offering agricultural advice or supplying treatment products. By mutual agreement, the cost of these products is deducted from the producer’s output at the point of sale. In some cases, more extensive forms of support are observed, such as assisting producers with the education of their children.

It is also noteworthy that the consistent increase in the purchase prices offered to mango producers has played a significant role in improving their incomes. Specifically, the unit purchase price for a box of mangoes rose from 2200 FCFA in 2015 to 2350 FCFA in 2019, corresponding to an average increase of 30 FCFA per box over the past five marketing seasons.

Finally, participation in the certification process—encompassing the adoption of good agricultural practices, enhancement of product quality, and improvement of producers’ working conditions—has frequently been identified as a key factor contributing to increased income for producers.

The long-term viability of the project’s initiatives depends on the ability of stakeholders within the mango sector—particularly the producers—to maintain the project’s outcomes after external support and interventions have ended. Various categories of factors may threaten this sustainability, including human and socioeconomic factors, agro-ecological conditions, and issues associated with the implementation of control methods.

Human and Socioeconomic Factors

Interviews reveal that some producers exhibit a marked lack of motivation to actively manage their own orchards. They tend to withdraw from direct involvement, delegating all intervention initiatives to factory operators and harvest technicians. This pattern of behavior appears to be typical among most mango producers in Korhogo, who are predominantly retired civil servants and thus occupy a rentier position. While the informal agreement between these producers and the factory operators remains mutually satisfactory, the arrangement may seem advantageous. However, should this tacit contract be disrupted for any reason, producers find themselves ill-equipped to address operational challenges, having been distanced from practical realities for an extended period and lacking the capacity to undertake even basic production improvement measures, particularly those related to controlling mango fruit flies.

Additionally, the dominant role of mango exporters in determining purchase prices has been identified as a significant source of demotivation among certain producers. This discouragement leads to a general disinterest in adopting improved production techniques, especially those aimed at combating fruit flies.

Agro-Ecological Factors

Historically, research institutions were the sole providers of mango seedlings used for establishing new orchards. While this was the case prior to the crisis, and even more so in its aftermath, there has been a proliferation of private nurseries. Although mango seedlings from these private nurseries are generally more affordable than those provided by research institutions, it is important to highlight that the phytosanitary quality of seedlings from private nurseries is often inadequate. Such seedlings are potential vectors for diseases that may jeopardize mango production.

Additionally, to prevent livestock from straying into young mango orchards, cashew trees are often planted as protective hedges. Observations at harvest time indicate that cashew apples left on the ground serve as significant refuges for fruit flies, which subsequently infest mango crops. If these cashew hedges are not also subjected to appropriate treatment, they can seriously undermine mango production by facilitating fruit fly infestations.

Constraints Associated with the Use of Control Methods

Several constraints are directly associated with the implementation of fruit fly control methods. Limited availability, high costs of treatment products, and the complexity of assembling application equipment are frequently identified as significant barriers to their use. Treatment products are notably expensive; for instance, a box of M3 is priced between 160,000 and 250,000 FCFA. TIMAYE is applied at a rate of 45 sachets per hectare, with each sachet costing 500 FCFA, resulting in a total expense of 22,500 FCFA per hectare. To maintain efficacy, this treatment must be reapplied every three weeks. The Succès Appât product costs 10,000 FCFA per liter, with producers required to contribute 125 FCFA per liter; this treatment must be renewed every ten days. Furthermore, gathering the necessary equipment for product application is often challenging. For example, 45 plastic water bottles per hectare are needed to construct the traps. The substantial volumes of water required for some methods also present a considerable constraint, particularly in regions where water is scarce during certain periods of the year. Additionally, some producers have reported the ineffectiveness of specific treatment products.

From a strictly scientific standpoint, it has been highlighted that the attractants currently used in traps lure and capture only a single genus of fruit fly, specifically the male. (Females, responsible for oviposition in mangoes, are not attracted by sexual lures.) This concerns the genus Bactrocera (species Bactrocera dorsalis). The three other genera—Ceratitis, Dacus, and Zeugodacus—are not targeted by existing traps. The potential emergence and proliferation of species from these three genera represent a significant threat to orchards.

Mango producers employ various combinations of fruit fly control strategies, with each combination represented by different proportions of producers (see Table 2 ). The first category, comprising approximately 5% of producers, consists of those who do not implement any fruit fly control measures.

Producers in the next three categories each rely exclusively on a single control method: approximately 3% use only sanitation, around 2.65% employ solely food baits, and about 5% utilize only sexual attractants. These groups are mutually exclusive within the sample.

Beyond these three categories, there are three additional groups of producers who employ a combination of two control methods, referred to as binary combinations:

The final category consists of producers who employ a combination of three control strategies, referred to as the ternary method, which simultaneously integrates sanitation, sexual attractant-based control, and food bait-based control. This category, which is the second largest, comprises around 23% of the mango producers in our sample ( Table 2 ).

The average size of a mango orchard is approximately 6 hectares (6.06) (see Table 3 ). This figure exhibits considerable variation depending on the combination of pest control methods employed, with orchard sizes ranging from 1.5 ha to 12 ha. Producers who utilize only sexual attractants, as well as those who combine sexual attractants with food baits, occupy an intermediate position in terms of orchard size. At the extremes, the largest average orchard sizes are associated with the use of three-method combinations, whereas sanitation and food bait-based control methods are typically employed on comparatively smaller areas (see Table 4 ).

1) Household Mango Sales Volumes and Factor Productivity

On average, each household sold approximately 10 tons of mangoes during the 2019 mango season ( Table 5 ). However, the volume of mangoes marketed varies significantly depending on the combination of fruit fly control methods employed ( Table 6 ). Marketed quantities range from less than 1 ton per household when only the food bait control method is used, to over 20 tons per household when a combination of three control methods is implemented. It is important to note that marketed quantities should be interpreted in relation to the cultivated area, which, as previously mentioned, also varies depending on the combination of control methods used ( Table 6 ).

2) Yield Levels

The average yield per household is 1.566 tons per hectare ( Table 7 ). On average, mango-producing households harvested 1.56 t/ha of mangoes suitable for marketing during the 2019 mango season ( Table 7 ). Nevertheless, this average masks considerable disparities, as shown in Table 8 . Yields range from approximately 0.5 t/ha to over 2 t/ha ( Table 8 ). Four distinct yield groups can be identified through analysis. At one end of the spectrum, the lowest yields are observed among producers employing only a single fruit fly control method, while the highest yields are achieved through the use of the sanitation method. Between these extremes are producers who either do not use any control method or employ binary or ternary combinations of control strategies: Single-method application (exclusive use of one control method): (AL): 0.57 t/ha and (ATR): 0.72 t/ha; No control method: None: 0.93 t/ha; Binary or ternary combinations: AL + S: 1.54 t/ha, ATR + AL: 1.62 t/ha, ATR + S: 1.71 t/ha; AL + ATR + S: 1.64 t/ha; and Sanitation: 2.19 t/ha ( Table 8 ).

3) Estimating Input Costs per Hectare Associated with Various Combinations of Control Methods

The implementation of pest control strategies necessitates the use of a range of agricultural inputs. As shown in Table 9 , the average expenditure per hectare on these inputs is 54,725 FCFA. Similar to other indicators, this average cost per hectare varies depending on the specific context, with values ranging from approximately 20,000 FCFA to 65,500 FCFA, as detailed in Table 10 . On average, sanitation, binary control methods, and ternary control methods incur the highest input costs. In contrast, the costs under the “No Method Applied” scenario reflect only the general agricultural production expenses (see Table 10 ).

4) Estimation of Gross Margin per Hectare Associated with Different Combinations of Control Methods

The mean gross margin per hectare is 100,317 FCFA; however, this figure ranges from approximately 17,000 FCFA to 200,000 FCFA, as shown in Table 11 and Table 12 . The mean gross margin per hectare serves to divide the eight average gross margin values, each corresponding to one of the eight control method combinations, into two distinct groups. Specifically:

5) Estimating the Total Production Cost Based on Different Combinations of Control Methods

The total production cost per hectare refers to the sum of input costs and the expenses associated with other orchard intensification and maintenance activities (see Table 13 and Table 14 ). On average, the total production cost per hectare amounts to 76,931 FCFA. However, this average conceals substantial disparities, similar to those observed for other indicators. Specifically, the total production cost per hectare ranges from approximately 20,000 FCFA to 127,840 FCFA.

Among the various control strategies, both ternary and binary combinations of control methods incur the highest total production costs per hectare, in comparison to other approaches. Notably, the average total production cost per hectare associated with ternary control methods is nearly double the regional average (refer to Table 14 ).

6) Estimating Net Benefit per Hectare According to Different Combinations of Control Methods

On average, mango producers in the region obtain a net benefit of approximately 95,000 FCFA (94781.51) per hectare (see Table 15 ). However, this figure is subject to considerable variation depending on the specific context. Binary combinations of control strategies, as well as sanitation measures, offer mango producers the highest net benefits, which are equal to or exceed the average net benefit.

In contrast, the simplest combinations of control methods, the reference case of “No Control Method Applied”, and the ternary combination of control methods result in the lowest net benefits per hectare. These net returns fall below the average net benefit (see Table 16 ).

7) Estimating the Value of a Workday Based on Different Combinations of Control Methods

The results show that, on average, mango cultivation in the region values an agricultural workday at 5085 FCFA, compared to an average wage labor cost of 1000 FCFA ( Table 17 ).

The mean value attributed to a workday varies substantially depending on the combination of pest control methods used, ranging from over 14,000 FCFA to less than 1000 FCFA. Sanitation practices yield a high valuation for the workday, whereas the ternary control method results in the lowest valuation, at less than 600 FCFA. In the case of binary combinations, there is considerable variability in the workday’s valuation. The use of sexual attractants alone values the workday at over 14,500 FCFA, a figure that appears abnormally high ( Table 18 ).

8) Estimating the Economic Efficiency of Mango Producers

The analysis reveals that the average unit cost of mango production is 74.92 FCFA per kilogram, while the average selling price is 108.50 FCFA per kilogram. Based on these calculations, approximately three-quarters of mango producers in the region can be classified as economically efficient. In contrast, around 20% of mango producers are identified as operating at a deficit (see Table 19 ).

As shown in Table 20 below, the Sinématiali area has the highest proportion of efficient producers, followed by the Ferkéssedougou area. In comparison, the Korhogo area has the largest concentration of mango producers operating at a deficit relative to the other two zones.

Two key performance indicators were selected to better evaluate the economic efficiency of mango producers in the region: export yield and the average production cost (average input cost) per hectare.

Efficient producers achieve export yields of mangoes that are twice as high as those recorded by deficit producers ( Table 21 ).

With respect to average input costs per hectare, the findings reveal that efficient mango producers incur average input costs per hectare that are half those of their inefficient counterparts ( Table 22 ). This disparity has a direct effect on net profit per hectare. The net profit per hectare for efficient mango producers is substantially higher than the regional average, whereas inefficient producers experience a significantly negative net profit per hectare. This group of producers thus operates at a loss ( Table 23 ).

The findings indicate that the mean yield increased from 1.15 t/ha in 2015 to 1.56 t/ha in 2019, corresponding to a 26.37% rise. This improvement is primarily attributed to the combined application of integrated pest management techniques—including sanitation, sexual attractants, and food baits—with binary and ternary combinations demonstrating clear superiority over single-method approaches. These results support the earlier work of [ 2 ], which demonstrated that integrated management strategies are more effective than isolated methods in reducing infestations and enhancing yields.

Sanitation-only methods yielded the highest average gross margin (191,632 FCFA/ha), followed by binary combinations such as sexual attractants plus sanitation (126,139 FCFA/ha). Conversely, the ternary combination, despite its effectiveness in yield improvement (1.64 t/ha), resulted in a lower net benefit (57,193 FCFA/ha) due to elevated production costs (127,838 FCFA/ha). These findings are consistent with the observations of [ 4 ], who noted that the profitability of agricultural practices depends not only on yield but also on the management of operational costs.

The analysis of economic efficiency revealed that 77.58% of producers operate efficiently, with an average production cost (45,476 FCFA/ha) significantly lower than that of less efficient producers (90,459 FCFA/ha). These efficient producers also achieve nearly double the export yields and report a net profit of 137,646 FCFA/ha, in contrast to an average loss of 82,805 FCFA/ha among inefficient producers. This observation corroborates the findings of [ 3 ], who highlighted the critical role of technical expertise and input management in driving the economic performance of agricultural enterprises.

The study identifies significant challenges to the long-term sustainability of pest control method adoption, especially in the absence of subsidies. Economic barriers (such as high input costs and water scarcity) and logistical difficulties (including implementation complexity) threaten to undermine the project’s achievements over the medium term. These findings underscore the need for supportive interventions, notably ongoing technical assistance and targeted input subsidy policies. This aligns with the recommendations of the [ 7 ], which stress the importance of incentive-based public policies to ensure the sustainability of integrated protection technologies.

The active participation of exporters, the training provided to producers, and the certification process have also played a critical role in enhancing income levels. These findings indicate that the success of agricultural development initiatives depends on a holistic approach that engages all segments of the value chain, in accordance with the recommendations of [ 8 ] in their analysis of agricultural systems.