2014 ASHS Annual Conference

In northern New Mexico, late frosts are the number one issue challenging tree fruit production. Good alternative crops with reliable yield are needed for the high pH soils, high elevations, and shorter growing seasons in northern New Mexico. Strawberries prefer slightly acid soil and exhibit leaf chlorosis in high pH soils. However, cultivars vary in their sensitivity to high pH soil based on their genetic background. In 2011, 16 strawberry cultivars were planted with two planting systems – a black plastic covered perennial system and a matted row system arranged in a split-plot block design with four replicates at the New Mexico State University Sustainable Agriculture Science Center at Alcalde, NM. Cultivars varied greatly in their yield and tolerance to high soil pH. ‘Allstar’, ‘Chandler’, and ‘Darselect’ were the three most sensitive cultivars to high soil pH among the 16 cultivars tested. ‘Wendy’, ‘Brunswick’, ‘Cavendish’, ‘Jewel’, and ‘Honeoye’ were the five most tolerant cultivars. Two to three applications of 20 g/30 m chelated iron product (FeEDDHA) per year through fertigation effectively corrected high pH (high lime) induced leaf chlorosis. After averaging the yields of 2012 and 2013, ‘Mesabi’ and ‘Kent’ had greater yield than others and twice the yield of ‘Jewel’. ‘Cavendish’ had the greatest yield in the first harvest season, but not in the second season. Early cultivars Earliglow and Annapolis, and late cultivars L’Amour and Ovation all had low yields in both years. On 16 Jan. 2013, the minimum temperature reached -21.7 °C, which caused crown winter damage to some cold-tender cultivars mainly in the black plastic covered system. ‘Wendy’, ‘Chandler’, ‘Clancy’, and ‘Jewel’ were the most cold-tender cultivars, while ‘Mesabi’, ‘Kent’, ‘Cavendish’, and ‘Honeoye’ were the hardiest cultivars among those tested. After repeated late frosts from 19 Apr. to 4 May 2013, most cultivars surprisingly produced greater yield than in 2012, with ‘Mesabi’ and ‘Kent’ being the greatest because late blooms compensated for the frost damage to early flowers and fruitlets. Growers should be selective with their cultivars, employ a fertilizer program, and use over-head sprinklers for frost protection. Strawberry production could be profitable in high pH soil at high elevation with short growing season in the Southwest.