Using agronomic tools to improve pineapple quality and its uniformity in Benin

Keywords: Ananas comosus; Benin; cultural practices; fruit quality; hapas; heterogeneity; planting material; slips; suckers; supply chain; variation in quality; variation within crop; vigour. Poor average quality and uniformity in quality have become major issues in agri-food chains. This is also the case in the pineapple sector in Benin where less than 2% of the fresh pineapple is exported to international markets. The average quality of pineapple delivered to other markets, local and regional, is poor. The present thesis studied the improvement options in the pineapple sector which will help pineapple producers to produce higher pineapple quality for different markets, including international ones. This thesis aimed at (1) understanding how fresh pineapple supply chains are organised in Benin and identifying the bottlenecks for delivering the right pineapple to the right market; (2) increasing our knowledge on the agronomic tools used by pineapple producers to produce pineapple fruits; (3) understanding how agronomic factors affect pineapple quality and harvesting time, and (4) proposing and discussing the trade-offs between cultural practices. Research included analysis of supply chains and cropping systems and field experimentation. To understand how fresh pineapple supply chains are organised, 54 semi-structured interviews were held with key informants and 173 structured interviews with actor groups. Results indicated six main actor groups in the fresh pineapple chains: primary producers, exporters, wholesalers (those selling at local markets and those selling at regional markets), processors, retailers, and middlemen. Two pineapple cultivars were grown: Sugarloaf and Smooth Cayenne, with Sugarloaf being dominant in local and regional markets and Smooth Cayenne in European markets. The main constraints hampering the effectivity of the chains were: the non-controlled conditions under which the pineapple was transported from one actor group to another, the lack of appropriate storage facilities at wholesaler’s and processor’s levels, the unavailability of boxes for export and the non-concordance between actor groups in which quality attributes and criteria they valued most. In addition, most respondents interviewed affirmed that the pineapple quality was highly heterogeneous, emphasising the need to understand how pineapple is grown in Benin and what the constraints for producing high pineapple quality are. To find out the agronomic tools in use by pineapple producers in Benin, interviews were held with 100 producers in the pineapple production areas. Pineapple production practices proved diverse for both cultivars in planting density, flowering induction practice and fertiliser application. The production systems of the two pineapple cultivars differed in planting material used (slips in cv. Sugarloaf; hapas plus suckers in cv. Smooth Cayenne); the use of K2SO4 (not commonly used in cv. Sugarloaf and commonly used in cv. Smooth Cayenne); the number of fertiliser applications (lower in cv. Sugarloaf than in cv. Smooth Cayenne) and in the maturity synchronisation practice by means of Ethephon (not commonly used in cv. Sugarloaf and commonly used in cv. Smooth Cayenne). Constraints for high quality production were the unavailability of planting material, unavailability and high costs of fertilisers and the heterogeneity in planting material weight. To understand how agronomic factors affect pineapple quality and harvesting time, four on-farm experiments were conducted in commercial pineapple fields. Results first indicated that the heterogeneity in fruit weight was a consequence of the heterogeneity in plant vigour at artificial flowering induction time. The plant vigour at flowering induction was mainly related with the infructescence weight and less or not with crown weight. Second, results indicated that artificial flowering induction gave fruits with lower infructescence weight and heavier crown than natural flowering induction. Artificial maturity induction reduced the total soluble solids (TSS) concentration in the fruits. Finally, results showed that the reason why a high proportion of fruits in cv. Sugarloaf was not exportable to Europe was the high value in the ratio crown: infructescence height (above 1.5); in cv. Smooth Cayenne, reasons were a ratio crown: infructescence height as well as a TSS below 12 ºBrix. To come up with improvement options for high pineapple quality production with low heterogeneity in quality, the possibility of pruning slips on selective plants as means to improve uniformity in fruit quality was evaluated through two on-farm experiments on commercial fields with cv. Sugarloaf. Results revealed that pruning of slips did not significantly improve average fruit quality attributes and was not successful in achieving more uniform fruit quality at harvesting time. Through one experiment per pineapple cultivar, we investigated how fruit quality and its variation were affected by weight (in both pineapple cultivars) and type (in cv. Smooth Cayenne only) of planting material. Results showed that fruits from heavy planting material had heavier infructescence and fruit weights, longer infructescence height, but shorter crown height and smaller ratio crown: infructescence height than those from light planting material. In cv. Sugarloaf fruits from heavy planting material had higher variation in crown weight and lower variation in infructescence height than fruits from light and mixed (light plus heavy) planting materials. In cv. Smooth Cayenne, fruits from heavy planting material had a lower variation in fruit height than fruits from other classes of planting material. The type of planting material (in cv. Smooth Cayenne) had no effect on the average fruit quality attributes except on the crown height where fruits from hapas had shorter crowns than those from suckers. The type of planting material had in overall no significant effect on the variation in the fruit quality attributes. The present study is a step towards the improvement of the whole pineapple sector in Benin. It identified constraints for high pineapple quality production but also tested and proposed improvement options for high pineapple quality production.