Jujube cultivars have been imported into the United States for more than 100 years, but cultivar trials have been limited. To accurately recommend cultivars for each region, trials have to be conducted. We have set up jujube cultivar trials at the New Mexico State University (NMSU) Alcalde (2015, USDA hardiness zone 6a), Los Lunas (2015, 7a), and Leyendecker (2017, 8a) Centers with over 35 cultivars at each site with two replicates and a complete random block design. We reported the early performance of fresh-eating cultivars in 2019. Here we report the performance of 19 drying and multipurpose jujube cultivars. Between 40% and 100% of jujube trees produced a few fruit to more than 100 fruit in the planting year, depending on cultivar and location. Trees were more upright at Los Lunas than at Alcalde. ‘Kongfucui’ (KFC) was the most productive cultivar at Alcalde with 13.3 kg/tree in 2019, followed by ‘Chaoyang’, ‘Jinkuiwang’ (JKW), ‘Pitless’, and ‘Lang’. The yield at Los Lunas was lower than Alcalde for the first 3 years after planting; however, ‘Jinsi 2’, ‘Jinsi 4’, ‘Jixin’, ‘Sherwood’, ‘Sihong’, and ‘Xiangzao’ produced higher yields at Los Lunas than Alcalde in 2019. All cultivars produced higher yields and contained higher soluble solids at Leyendecker than Alcalde and Los Lunas at similar ages. ‘JKW’ was the most vigorous and productive cultivar at Leyendecker. ‘JKW’, ‘Xiangzao’, and ‘Lang’ produced more than 3.0 kg/tree in their second year after planting. ‘JKW’ yielded 12.3 kg/tree in its third year after planting. Among the three locations, drying cultivars are not recommended for commercial production at Alcalde. However, home gardeners can plant multipurpose and early-drying cultivars at Alcalde. Leyendecker produced the best dry fruit with larger fruit size, rich color, and meaty fruit; dry fruit quality was acceptable in most years at Los Lunas except 2019. We preliminarily recommend some drying and multipurpose cultivars for each location. As trees mature and produce more fruit, we will fine-tune the cultivar recommendations. We also discuss the jujube cultivar zoning information in New Mexico and fruit uses.

Jujube (Ziziphus jujuba Mill.) is also called Chinese date. There are ∼100 jujube cultivars with limited commercial availability, and the majority of them have scant details in the United States. In this study, nutrient dynamics during fruit maturation of different jujube cultivars grown at Las Cruces, Los Lunas, and Alcalde, NM, were examined in 2018 and 2019. Cultivars varied by location and year, and included ‘Li’, ‘Lang’, ‘Sugarcane’, ‘September Late’, and ‘Sherwood’. Parameters tested were total phenolic content (TPC), proanthocyanidins (PAs), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant capacity: 2,2-diphenylpicrylhydrazyl radical scavenging capacity and ferric reducing antioxidant potential (FRAP). Moisture, TPC, PAs, FRAP, and vitamin C content decreased with fruit maturity; however, the latter stage of fruit maturity showed an increase in cAMP. Compared with fruit at full-red maturity, creamy fruit had TPC, PA, FRAP, and vitamin C concentrations that were 1.0 to 1.8, 4.4 to 12.4, 1.9 to 2.6, and 0.1 to 1.3 times higher, respectively, depending on location (P < 0.05). From creamy to full-red maturity, cAMP increased by 0.9 to 4.5 times. At full-red maturity, estimated TPC in jujube fruit ranged from 10.6 to 16.8 mg gallic acid equivalent per gram dry weight (DW), whereas estimated PAs ranged from 1.8 to 5.3 mg PA B2/g DW. Jujube fruit at full-red maturity had a vitamin C content that ranged from 649.0 to 1153.3 mg/100 g DW. At full-red maturity, the concentration of cAMP ranged from 148.1 to 277.6 μg/g DW in Las Cruces samples.

Jujube, commonly known as the Chinese date, is a nutritious fruit with medicinal importance. Fresh jujube fruits have a shelf life of about ten days in ambient conditions that can be extended by drying. However, nutrition preservation varies with the drying method and parameters selected. We studied total phenolic content (TPC), proanthocyanidins (PA), vitamin C, cyclic adenosine monophosphate (cAMP), and antioxidant activities in jujube fruits dried with freeze-drying (FD), convective oven drying (OD) at 50 °C, 60 °C, and 75 °C, and sun drying (SD) with FD as a control. The cultivars used for this study were ‘Capri’ and ‘Xiang’ from Las Cruces in 2019, and ‘Sugarcane’, ‘Lang’, and ‘Sherwood’ from Las Cruces and Los Lunas, New Mexico, in 2020. Freeze-drying had the highest of all nutrient components tested, the best estimates of mature jujube fruits’ nutrient contents. Compared with FD, the majority of PA (96–99%) and vitamin C (90–93%) was lost during SD or OD processes. The retention rates of antioxidant activities: DPPH and FRAP were higher in OD at 50/60 °C than SD. SD retained a higher cAMP level than OD at 50/60 °C in both years. The increase in oven drying temperature from 60 °C to 75 °C significantly decreased TPC, PA, antioxidant activities, and cAMP.