Interest in hydroponic home gardening has increased in recent years. However, research is lacking on minimum inputs required to consistently produce fresh produce using small-scale hydroponic systems for noncommercial purposes. Our objectives were to 1) evaluate the effect of biweekly nutrient solution replacements (W) vs. biweekly fertilizer addition without a nutrient solution replacement (W/O) on final growth, yield, and nutrient uptake of hydroponic tomato (Solanum lycopersicum) plants grown in a greenhouse, and 2) characterize growth over time in a greenhouse or an indoor environment using W. For each environment, ‘Bush Goliath’ tomato plants were grown for 12 weeks in 6.5-gal hydroponic systems. The experiment was replicated twice over time. In the greenhouse, plants were exposed to the following day/night temperature, relative humidity (RH), and daily light integral (DLI) in 2018 (mean ± SD): 31 ± 6/22 ± 2 °C, 67% ± 8%, and 32.4 ± 7 mol·m‒2·d‒1; and in 2019: 28 ± 6/22 ± 3 °C, 68% ± 5%, and 27.7 ± 6 mol·m‒2·d‒1. For both experimental runs indoors, the day/night temperature, RH, and DLI were 21 ± 2 °C, 60% ± 4%, and 20 ± 2 mol·m‒2·d‒1 provided by broadband white light-emitting diode lamps. The W/O treatment resulted in a higher-than-desired electrical conductivity (EC) and total nutrient concentration by the end of the experiment. In addition, compared with the W treatment, W/O resulted in less leaf area, more shoot growth, less water uptake, and similar fruit number—but increased blossom-end-rot incidence, delayed fruit ripening, and lower fruit fresh weight. Nonetheless, the final concentration of all nutrients was almost completely depleted at week 12 under W, suggesting that the applied fertilizer concentration could be increased as fruiting occurs. Surprisingly, shoot biomass, leaf area, and leaf number followed a linear trend over time in both environments. Nonetheless, given the higher DLI and temperature, greenhouse-grown plants produced 4 to 5 kg more of fruit than those grown indoors, but fruit from plants grown indoors were unaffected by blossom-end-rot. Our findings indicate that recommendations for nutrient solution management strategies should consider specific crop needs, growing environments, and production goals by home gardeners.
Elisa Solis-Toapanta, Paul R. Fisher, and Celina Gómez
Andre Luiz Biscaia Ribeiro da Silva, Joara Secchi Candian, Lincoln Zotarelli, Timothy Coolong, and Christian Christensen
Soil nitrogen (N) is easily leached in cabbage (Brassica oleracea var. capitata) production areas of southeastern United States characterized by sandy soils with low water-holding capacity. Soil N leaching in these areas is increased after rainfall events; consequently, growers increase the fertilizer N application to protect against N deficiencies and yield loss. The objective of this study was to evaluate the effects of three fertilizer N rates on yield and head quality for common cabbage cultivars used by Florida and Georgia growers during four cabbage growing seasons. Field experiments were conducted in Hastings, FL, in 2016 and 2017, and in Tifton, GA, in 2018 and 2019. A randomized complete block design was used with a split-plot design of fertilizer N rate and cabbage cultivar. Fertilizer N rate treatments consisted of the application of 170, 225, and 280 lb/acre N and were assigned as the main plot. Cabbage cultivars Bravo, Bronco, Bruno, Capture, Cheers, and Ramada were assigned as the sub-plots. Weather conditions were monitored during all growing seasons, and total, marketable, and unmarketable yields, as well as cabbage head polar and equatorial diameters, and core height and width were measured. In Florida, there was a significant interaction for growing season and fertilizer N rate. The Florida 2016 cabbage season experienced 10.5 inches of rainfall, and fertilizer N rates had no effect on cabbage yields. Total and marketable yield averaged 45,391 and 38,618 lb/acre among fertilizer N rates in 2016, respectively. Rainfall accumulated 2.1 inches during the 2017 study in Florida, which was less than the crop evapotranspiration. In response, total and marketable yield were higher for the applications of 225 lb/acre N (51,865 and 49,335 lb/acre, respectively) and 280 lb/acre N (54,564 and 52,219 lb/acre, respectively) compared with the application of 170 lb/acre N (47,929 and 43,710 lb/acre, respectively). In Georgia, there were no significant interactions between production season and fertilizer N rates. In addition, there were no significant main effects of season or fertilizer N rate. Rainfall events accumulated 20.9 and 7.8 inches during the 2018 and 2019 growing seasons, respectively. Total and marketable yields averaged 37,290 and 33,355 lb/acre, respectively for the two growing seasons in Georgia. Cabbage cultivar had no interaction with fertilizer N rate in any location. ‘Cheers’ (52,706 lb/acre) had the highest total yield in Florida, and ‘Ramada’ (38,462 lb/acre) and ‘Bronco’ (39,379 lb/acre) had the highest total yields in Georgia. In conclusion, the application of 225 lb/acre N was sufficient to sustain cabbage yields, but yields of the 170- and 225-lb/acre N treatments were not different when rainfall events exceeded crop evapotranspiration.
Magdalena Pancerz and James E. Altland
Stability of substrate pH in container-grown crops is important for proper nutrient management. The objective of this research was to determine the pH buffering capacity of pine bark substrates as a function of particle size and compare those results to sphagnum peat. The weight equivalent of 100 cm3 for fine, medium, and coarse pine bark and sphagnum peat, either as a whole or partitioned into several particle size ranges, was placed in a 250-mL glass jar and filled with 100 mL of an acid or base solution ranging from 0 to 50 meq·L−1 in 10 meq·L−1 increments. After 24 hours, pH was measured. An experiment was also conducted in the greenhouse. The weight equivalent of 500 cm3 of sphagnum peat, fine pine bark, or coarse pine bark was filled into 10-cm plastic pots and irrigated with one of the following: tap water or 10 meq·L−1 of HCl, NaOH, H2SO4, or KHCO3 and with or without a water soluble fertilizer. Substrate pH was determined 4 and 8 weeks after potting using the pour-through method. In all experiments, sphagnum peat had less buffering capacity than pine bark against pH changes from acidic solutions, whereas pine bark had less buffering capacity than sphagnum peat to pH changes from basic solutions. Substrate pH buffering in pine bark increased with decreasing particle size, whereas pH buffering in sphagnum peat was less responsive to particle size. These results will help growers and substrate manufacturers understand how substrate components contribute to pH management during crop production.
Christopher J. Currey, Vincent C. Metz, Nicholas J. Flax, Alex G. Litvin, and Brian E. Whipker
The objective of this research was to quantify the effects of phosphorous (P) concentrations on the growth, development, and tissue mineral nutrient concentrations of four popular culinary herbs commonly grown in containers. Seedlings of sweet basil (Ocimum basilicum ‘Italian Large Leaf’), dill (Anethum graveolens ‘Fernleaf’), parsley (Petroselinum crispum ‘Giant of Italy’), and sage (Salvia officinalis) were individually transplanted to 11.4-cm-diameter containers filled with soilless substrate comprising canadian sphagnum peatmoss and coarse perlite. Upon transplanting and throughout the experiment, seedlings were irrigated with solutions containing 0, 5, 10, 20, or 40 mg·L−1 P; all other macro- and micronutrient concentrations were the same across P concentrations. Plants were grown for 4 weeks in a greenhouse; after that time, data were collected. Relationships between height and width and P concentrations were nonlinear for all four species; height and width increased as P increased to more than 0 mg·L−1 until the species-specific maxima; after that time, no further increase occurred. The same trend was observed for the branch length of sweet basil and sage, and for internode length, leaf area, and shoot dry mass of all four species. Although visible P deficiency symptoms were observed for plants provided with 0 mg·L−1 P, there were no signs of P deficiency for plants provided with ≥5 mg·L−1 P, even though tissue P concentrations were below the recommended sufficiency ranges. As a result of this research, containerized sweet basil, dill, parsley, and sage can be provided with 5 to 10 mg·L−1 P during production to limit growth and produce plants without visible nutrient deficiency symptoms that are proportional to their containers.
Eric T. Stafne
Since late Mar. 2020, many universities halted normal operations due to the Coronavirus Disease 2019 (COVID-19) pandemic. Although extension uses many different techniques to educate consumers, it has been slow to grasp the power of social media. Faced with a dilemma of using digital methods instead of in-person field days, short courses, and workshops, Twitter was a viable alternative, especially for broad audience engagement. Tweet threads were posted on Twitter every Monday morning from 6 Apr. to 8 June 2020. Each thread consisted of 10 tweets. A hashtag #YardFruits was used to start the thread and for later reference. For the first nine threads only one fruit species was discussed per thread. The final thread consisted of single tweets of several species. Engagement percentage did not differ over time but did differ among the crop species. Tweets that did not include a photo received less engagement (2.7%) than those that did include a photo (4.7%). My Twitter account saw a 6.5% increase in followers during the series. Grape (Vitis sp.), passion fruit (Passiflora sp.), fig (Ficus carica), and pear (Pyrus communis) threads had the least engagement and were different from the Other Fruits thread. All other threads were similar. Extension educators can grow their influence by using well-targeted, focused tweets and tweet threads, especially those that use hashtags and photos.
Gurjit Singh, Shimat V. Joseph, and Brian Schwartz
The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an important pest of warm-season turfgrass species, including bermudagrass (Cynodon spp.). Bermudagrass is a popular turfgrass that is widely planted on golf courses, athletic grounds, and ornamental landscapes across the country and throughout the world. Spodoptera frugiperda infestation is often sporadic; however, when it does occur, damage can be severe. Host plant resistance against S. frugiperda can be a valuable tool for reducing or preventing the use of insecticides. Therefore, the objective of this study was to determine resistance against S. frugiperda in a few promising bermudagrasses. Fourteen experimental bermudagrass genotypes plus two control cultivars, ‘Zeon’ zoysiagrass (resistant control) and ‘TifTuf’ bermudagrass (susceptible control), were evaluated against S. frugiperda to determine host plant resistance in the laboratory. The results showed that the resistant control, ‘Zeon’ zoysiagrass, was more resistant than the other genotypes to S. frugiperda larvae. To determine the response of the experimental lines to S. frugiperda as compared with that of the controls, three indices were developed based on survival, development, and overall susceptibility. According to the susceptibility index, ‘13-T-1032’, ‘T-822’, ‘11-T-510’, ‘12-T-192’, ‘11-T-56’, ‘09-T-31’, ‘11-T-483’, and ‘13-T-1067’ were the top-ranked bermudagrasses. Among these, the responses of ‘13-T-1032’, ‘T-822’, ‘11-T-510’, ‘11-T-56’, ‘09-T-31’, and ‘11-T-483’ were comparable to that of ‘TifTuf’, and antibiosis was the underlying mechanism of resistance. Additionally, larval length, head capsule width, and weight were negatively associated with the days of pupation and adult emergence and positively associated with pupal length, thorax width, and weight. These results will help refine future breeding and with investigations of resistance against the fall armyworm.
Shengrui Yao, Robert Heyduck, Steven Guldan, and Govinda Sapkota
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.
Ayoub Fathi-Najafabadi, Cristina Besada, Rebeca Gil, and Alejandra Salvador
Persimmon cultivation has significantly grown in the Mediterranean Region in recent years. The production concentrates mainly in three astringent cultivars: Kaki Tipo in Italy, Triumph in Israel, and Rojo Brillante in Spain. Therefore, the varietal range expansion is one of the current challenges for persimmon producers in this area. Moreover, the introduction of nonastringent persimmon cultivars is particularly interesting because they can be commercialized immediately after harvest without applying deastringency treatment before commercialization. This study evaluated the harvest period and the postharvest response of six Japanese nonastringent cultivars (Kanshu, Shinshu, Soshu, Suruga, Youhou, Izu). During two seasons, fruit from each cultivar were harvested at two maturity stages. Fruit quality (external color, firmness, and total soluble solids) was evaluated after harvest and after different commercial scenarios (domestic market: 7 days at 20 °C, market to European Union (EU): 5 days at 5 °C plus 5 days at 20 °C, and market to countries with cold-quarantine treatment requirements: 21 days at 0 °C plus 5 days at 20 °C). Cultivars Kanshu, Shinshu, Soshu, and Izu were identified as early cultivars, and Soshu was the earliest one, which reached commercial maturity at the beginning of September. These four cultivars showed good quality after simulating commercialization on domestic and EU markets. Cultivars Suruga and Youhou overlapped the current harvest window, but their low chilling injury sensitiveness is highlighted, so they are of special interest to be cold-stored at the end of the season to be commercialized in overseas markets.
Roy D. Flanagan III, Jayesh B. Samtani, Mikel Ann Manchester, Stephanie Romelczyk, Charles S. Johnson, Watson Lawrence, and Jeremy Pattison
Strawberries (Fragaria ×ananassa) are one of the major high-value crops in North America. There is increasing interest in commercial strawberry production for local markets in Virginia and surrounding states, but information on the performance of newer cultivars is extremely limited. We tested 10 commercially available June-bearing cultivars [Benicia, Camarosa, Camino Real, Chandler, Strawberry Festival, Flavorfest, FL Radiance, Treasure, Sweet Charlie, and Winterstar™ (FL 05-107)] and two day-neutral cultivars (Albion and San Andreas) for their spring and summer fruiting capacity in Virginia production systems in a randomized, replicated study, at three on-farm locations. Data were collected on vegetative growth, yield performance, fruit quality, sweetness, and fruit diameter. Cultivars with the highest total yields averaged across all three locations were Benicia, Camino Real, Chandler, and Camarosa. ‘Camino Real’ had the highest marketable yield at all three locations, not significantly different from ‘Chandler’, and ‘Benicia’ and ‘Camarosa’ had the highest marketable yield at two of the three locations. ‘Flavorfest’ and ‘Sweet Charlie’ had the highest total soluble solids concentration for the harvest season. Overall, for all locations, ‘Benicia’ and ‘Camino Real’ had the largest fruit diameter, and ‘Strawberry Festival’ had the smallest fruit diameter.
Luis O. Duque
Sweetpotato (Ipomoea batatas) production in Pennsylvania and the northeastern United States has been increasing steadily. The performance of eight commercially available sweetpotato varieties and two unreleased accessions grown on raised beds and covered with black plastic mulch in Pennsylvania was evaluated. All varieties and accessions were evaluated in 2 successive years (2018 and 2019) at Rock Springs, PA. There were statistically significant differences in total marketable yield (TMY), but not in all yield components in both years. ‘Orleans’, ‘Beauregard’, ‘Averre’, and ‘Covington’ consistently produced high marketable yields and suitable U.S No.1 grade storage roots. ‘Bonita’ (tan skin/white flesh) and ‘Carolina Ruby’ [red skin/orange flesh (OF)] produced consistent yields in both years (range, 330–430 bushels/acre; 50-lb bushel). NC413 [purple skin (PS)/purple flesh (PF)] produced the lowest yield in 2018 and was discarded for future trials. In 2019, NCP13-0030 (PS/PF) produced good yields and shapes comparable to OF varieties. Overall total yields (TYs) measured in this study compared satisfactorily with average nationwide yields, with several varieties producing more than 500 bushels/acre.