Articles
INTENSIVE CROP REGULATION STRATEGIES IN SWEET CHERRIES
Sweet cherry production worldwide is now in the earliest stages of a cultural revolution toward high density orchards, with the introduction of precocious, vigor-controlling rootstocks and intensive management.
Such high density sweet cherry production offers significant potential horticultural advantages as well as unique potential cropping risks.
Preliminary results from an extensive trial planted in 1995, utilizing ‘Bing’ and ‘Rainier’ sweet cherry, eight high density training systems (four trellised and four self-supported) and four new clonal rootstocks (Gisela 5, GI 6, GI 7, GI 11) plus Mazzard seedling, will be presented.
Precocious flowering was significant on all of the Gisela rootstocks in the 3rd season (1997) after planting, but the potential crop was lost to spring frost.
Flowering was very heavy on all Gisela stocks and most training systems in the 4th season (1998), with resulting overcropping and small fruit size.
In a related experiment, crop loads were manipulated by flower bud thinning prior to bloom to begin determining crop management levels necessary to maintain fresh market fruit quality.
When the number of floral buds was reduced from natural levels (3 to 4 per node) down to 1 to 2 per node, total yield decreased by 17 to 25%, average fruit size increased as much as 43%, and soluble solids increased by up to 13%. The important interactions between precocity, tree architecture management, yield, and fruit quality will be discussed.