2017 ASHS Annual Conference

The new apple variety released by Washington State University’s breeding program, named Cosmic Crisp^TM (Enterprise x Honeycrisp), has been characterized by an upright and spreading growth habit (like Granny Smith is a Type IV) with high vigor. This variety mainly crops on spurs borne on two-year-old wood and one-year-old short shoots (Brindilla). It presents the tendency to produce in the outer part of the canopy and leave blind wood near the trunk. The fruit is crisp, firm and juicy with non-browning flesh and consistently shows excellent long-term storability. First trees of the variety will be planted in 2017 in Washington State only, so optimization of the performance in terms of growth and productivity could be very beneficial to the local fruit industry. Cosmic Crisp^TM pilot orchards were planted in 2013 at two sites (WSU Wenatchee Sunrise Orchard and WSU Prosser Roza Orchard). Their performance was evaluated in two training systems (vertical spindle system and V-system), grafted on two rootstocks (Geneva 41 and M9-Nic29) and pruned with two techniques ("bending" and "click"). The planting density for spindle is 3 ft x 10 ft (1,499 trees/A) and for the V system 1.5 ft x 10 ft (2,997 trees/A). Pruning weights and time, vegetative parameters, yield, fruit size/grading and fruit quality at harvest and after 6-month-storage, were assessed and performed for 3 years. In 2015 and 2016, flower bud count, fruit set and length of blind wood were counted and measured on selected trees. The highest value of trunk cross-sectional area (TCSA) and annual trunk growth were reported for spindle trees in both Sunrise and Rosa orchard locations. Spindle had higher yield per tree in both locations. Yield per acre was higher in V system in Roza only. Different results in terms of fruit quality were obtained in 2015 depending on the location, this reflects the two different environmental conditions investigated in the trial. “Click” pruning technique yielded fruit with more intense red color than “bending” after 1 month storage (only in Sunrise), had higher soluble solids content (SSC) and higher dry matter % than “bending” fruits both after 1 month (both locations) and 6 months storage (only Sunrise).