Issue link: https://read.dmtmag.com/i/514197
www.goodfruit.com GOOD FRUIT GROWER JUNE 2015 35 The steps toward high yields of quality Honeycrisp start with "excellent preplant soil preparation," he said. The next step is high planting densities of 1,200 to 1,900 trees per acre—two to three feet apart in row and 11- to 12-foot alleys. Growers should use improved rootstocks and match them to the proper spacing. The Geneva rootstocks are becoming available in larger quantities, and they offer higher fire blight and replant disease resistance than the rootstocks growers have been using. For trees spaced 2.5 feet apart, Robinson recommends Geneva 41 or G.214. For three-foot spacings, he suggests G.935, G.222, G.202, or G.814. Plantings need to have precise irrigation, he said, recommend- ing 100 pounds of nitrogen applied each year, preferably spoon- fed through the irrigation system. Using pruning Robinson recommends that growers manage cropload first by pruning with a goal of leaving from 1.8 to 2.0 flower buds for each fruit they want on the tree. On tall spindle, where renewal pruning is used, that means removing from one to three of the largest limbs as a first step. The remaining branches should be columnarized—simplified—by removing unwanted side or upright branches. The third step is shortening pendant, weak branches to reduce bud load. Then count remaining flower buds and continue removing them as needed. Once trees are pruned, the remaining excess fruits need to be removed by repeated chemical thinning, starting at bloom, with the goal of improving return bloom. Phil Schwallier, the Michigan State University tree fruit educa- tor serving apple growers in western Michigan, says Honeycrisp trees are easy to thin chemically when young but are more diffi- cult to thin when mature and vigor is lower. He recommends that growers start early and nibble away at the crop, ending with as little hand thinning as possible. There is some evidence that multiple apples on spurs reduce return bloom, so apples should be thinned to singles as much as possible. Stopping drop Schwallier also spoke at the IFTA Honeycrisp workshop about using NAA (naphthaleneacetic acid) and ReTain (aminoethoxyvi- nylglycine) as tools to prevent large losses caused by drop during harvest. Honeycrisp is extremely prone to drop. "Honeycrisp has an intermediate level of sensitivity to ReTain," he said. "A half rate of ReTain will provide maturity and stop drop protection similar to a full rate on normal varieties. For Honeycrisp, half rate is full rate. Best results are a half rate of ReTain plus NAA applied early, near 30 days before harvest. Some growers are using a quarter rate of ReTain, which will work in cool or non-stressful years, but in stressful years at least a one-third rate should be used with NAA." Schwallier's research has shown that ReTain and NAA are best used together, as the combination improves performance of both materials. NAA inhibits separation at the abscission zone for seven days, he said. But NAA also stimulates ethylene production and hastens ripening. Adding ReTain blocks the ethylene production from the NAA, allowing ReTain to extend the harvest season and move the harvest window about ten days into the future. • "Three management factors have a large impact on Honeycrisp fruit quality and should be managed by growers very precisely. They are fruit load, fruit nitrogen content, and irrigation." —Terence Robinson VAPOR GARD ® FOR CHERRIES AND APPLES SEE LABEL FOR ADDITIONAL INFORMATION AND ALWAYS READ AND FOLLOW LABEL DIRECTIONS N o G en e r i c S ub s ti t u t e ! A CONSISTENT PERFORMER CONFIDENCE Comes from 40 years and over 150,000 acres treated with VAPOR GARD. That's why many Growers, Consultants, Pest Control Advisors and Packing Houses understand VAPOR GARD's BENEFITS and VALUE on CHERRIES. MILLER CHEMICAL & FERTILIZER CORP. 800-233-2040 ➤INCREASED SIZE & YIELD ➤REDUCED SPLITTING ➤INCREASED SHELF LIFE Using VAPOR GARD on cherries offers growers these benefits: ➤INCREASED SIZE & YIELD ➤REDUCED SPLITTING (with early application) (from untimely rain) ➤INCREASED SHELF LIFE (greener stems) Don Waddle - Bleyhl Farm Service – Grandview, WA I like to use Vapor Gard on club and specialty varieties of apples to reduce sunburn. Growers like to apply Vapor Gard starting at the beginning of the sunburn season. Vapor Gard is consistent and always works well. Ed Hanks - SP Farms – Toppenish, WA "We used Vapor Gard on cherries every year it was needed for cracking prevention. I used it before rain and it seemed they didn't split as bad. We'd normally used it a couple times a year. I was always happy with Vapor Gard. I wouldn't grow cherries without it." Ed Sherman - Sherman Orchard Inc. – Quincy, WA I have used Vapor Gard for years for rain protection with great results. No shipping restrictions and greener stems are a great plus. I see that my cherries stay firmer longer with Vapor Gard. Vapor G ard has more benefits than just rain protection."