Pollinators’ contribution to seed yield in two self-fertile almond varieties role of bees for self-fertile almonds

Decreasing the dependence on external inputs to crop yield maximization is one of the main objectives of agricultural breeding programs. For this reason, new crop varieties once highly dependent on pollinators have been developed to be self-fertile and are now cultivated as pollinator-independent. However, the contribution of pollinators to these varieties remains unknown. In this study, we evaluated pollinators’ contribution to two self-fertile almond varieties (Marta and Marinada) and the density of pollinators needed to ensure adequate pollination. We measured the effects of pollinators on fruit set, seed yield, and pollination limitation at the tree level. Managed honeybees and wild bumblebees were the main floral visitors in both varieties. Both fruit set and seed yield were ~ 50% higher in pollinated trees than in excluded ones in the two varieties. We found no evidence of pollination limitation, suggesting that pollinators’ abundance was sufficient for adequate pollination. We recommend that almond growers actively manage pollinators to maximize seed yield and profits in these self-fertile varieties.