Pollination requirements of loquat ( Eriobotrya japonica Lindl.), cv. `Algerie'

Introduction. Loquat shares with other pomes, such as apple (Malus domestica ) and pear (Pyrus communis ), flowering habits, but, in contrast with them, the tree is considered a self-compatible species. However, when planted in solid blocks under mesh, low fruit set and small fruit size are often reported. To explore in which way restrictions of bee activity and/or impediments for cross-pollination can be responsible for low productivity and poor fruit quality, we carried out controlled pollination on flowers of loquat cv. Algerie. Materials and methods. A first experiment checked cross-pollination response by comparing fruit set and quality from self-, open-, and cross-pollinated flowers. A second experiment explored poor pollination effects by modifying the number of stigmas being hand cross-pollinated. Results. Cv. Algerie loquat flowers cross-pollinated with pollen of cvs. `Tanaka' and `Golden Nugget' loquat flowers produced more fruits of higher quality (larger, heavier and more precocious) than flowers under self-pollination. Benefits of cross-pollination can be explained by an earlier and higher level of fertilization. Observations under microscopy showed, however, that self-incompatibility of cv. Algerie flowers is not complete, and a certain level of self-fertilization occurs. The second experiment demonstrated that limiting the number of stigmas pollinated resulted in a significant reduction in the number of seeds formed that, in turn, affected fruit size and shape. Flowers with only one stigma pollinated seldom formed more than two seeds while flowers with all five stigmas pollinated produced fruit with an average of four seeds. Conclusion. Our results emphasize a dependence of cv. Algerie flower pollination on both adequate activity of pollinator insects and appropriate placement of pollinizers.