New cherry rootstock and cultivar interactions directly affect orchard profitability

Abstract

Due to increased production costs, Wasco County Oregon, USA cherry growers have found it difficult to remain profitable in recent years. Despite production increases in the last 30 years, average yields ha(-1) have actually fallen slightly to 10.5 t ha(-1). A newly developed cost of production study determined that at the average price received (US$ 2.14 kg(-1)), the break-even yield for ‘Bing’ cherries is 14 t ha(-1). New scion and rootstock cultivar releases have provided growers with the means to exceed this economic benchmark. In a rootstock trial in The Dalles, Oregon, ‘Bing’ cherries on ‘Krymsk 5’ rootstock yielded 21.0 t ha(-1) and ‘Krymsk 6’ yielded 21.7 t ha(-1) (5th-8th leaf). A new, productive, dwarfing rootstock series released by Michigan State University, named CoretteTM, consisting of five rootstocks: ‘Cass’, ‘Clare’, ‘Clinton’, ‘Lake’ and ‘Crawford’, also showed potential to significantly increase yields. The average number of flowers per leader cross-sectional area for ‘Bing’ on ‘Gisela 6’ was about 10 flowers cm(-2), but ‘Lake’, ‘Clare’ and ‘Crawford’ all had significantly more flowers with ‘Lake’ producing more than 20 flowers cm-2. However, in order to produce quality fruit, fruit on all five rootstocks were thinned to obtain a standard crop load. No differences in average fruit size were found between the five Corette™ rootstocks and the ‘Gisela 5’ and ‘Gisela 6’ controls in 2012 and 2013. The Krymsk rootstocks produced sufficient yields for growers to exceed all costs of production and the Corette™ rootstocks have similar potential. In addition to rootstock effects on yield, differences between cultivars also have a direct effect on profitability. Newly released cultivars offer growers an alternative to low-producing cultivars. Data from a cultivar evaluation trial in The Dalles, Oregon is presented.