Self-pollination does not affect fruit set or fruit characteristics in almond (Prunus dulcis)

P>Self-compatibility has become one of the most important traits in almond breeding programmes. This characteristic allows for the establishment of monovarietal almond orchards with many advantages for the grower. However, there are some uncertainties about the consequences of self-fertilization regarding productivity and fruit quality. In this work, a new methodology was used to clarify the possible effects of self-pollination on these parameters. Four different pollination treatments were applied to six self-compatible almond genotypes by hand-pollinating flowers on five different branches, so that along each branch the four treatments were distributed homogeneously. The pollinated flowers were later identified with wires of a particular colour for each treatment. Fruit set and fruit characteristics (weight in-shell, kernel weight, percentage of kernel, percentage of defective kernels, double kernels and split kernels) were studied. With this methodology, results should only be influenced by the pollinator effect. In general, no significant differences were observed between self-pollination and cross-pollination for the characteristics studied. These findings demonstrate the absence of negative effects of self-pollination on these agronomic traits.