Yield, Pollination Aspects and Kernel Qualities of Almond (Prunus Dulcis)Selections Trialed in the Southern San Joaquin Valley

Abstract

A field trial was established in the southern San Joaquin Valley to determine yield potential for nine almond selections grown under commercial conditions. Kernel yields were first quantified in 2008 at the end of the third growing season and continued through the 2010 harvest. Harvested tonnage varied significantly, depending on the particular accession, specific field location and harvest year. The almond accessions were genotyped for S-locus alleles, characterized phenologically during bloom, and analyzed for kernel dimensions, pellicle color profiles, nut defects and harvest quality parameters. Bloom duration and overlap of the nine experimental accessions generally coincided with that of 'Nonpareil' during the three examined bloom periods. Analysis of S-alleles revealed semi- or cross-incompatible pairs with some commercial cultivars, and confirmed the self-compatibility status of four of the trialed selections. Harvest year effects were significant on all examined kernel shape and appearance characters as well as all nut defects and harvest quality parameters except for the level of blank and shriveled kernels. Cumulative kernel yield differences and specific character faults have led to the removal of five accessions from the trial after three harvest seasons.