@article{freedman_rana_hoffmann_2022, title={Phenology Based Variability of Tissue Nutrient Content in Mature Muscadine Vines (Vitis rotundifolia cv. Carlos)}, volume={12}, ISSN={["2077-0472"]}, DOI={10.3390/agriculture12111805}, abstractNote={Muscadine (Vitis rotundifolia) is a grape species that is native to the Southeastern US, where several cultivars are grown commercially for processing or direct consumption. Phenology based tissue analysis to determine the nutritional status of a vine is a critical tool for growers to understand fertilizer demands in a vineyard. For European-style wine grapes, tissue sampling for nutrient content is well researched. However, current tissue sampling recommendations for muscadines are solely based on anecdotal knowledge. It is currently unknown if the type of tissue collected has an impact on variability and content of nutrients. Questions also remain as to whether or not seasonal vine phenology impacts tissue nutrient content. Without this knowledge it is difficult for a muscadine grower to make informed decisions on the nutritional status of a muscadine vine. Therefore, we investigated the impact of the phenological vine stage (bloom, fruit set, véraison) on nutrient content in two different tissue types (mature leaf vs. petiole), sampled at two different positions on a muscadine vine (opposite of cluster vs. shoot). The study was conducted over two growing seasons (2019 and 2020) in a commercial mature muscadine vineyard (‘Carlos’). Our results show that over both study years, the highest variability in nutrient content was found during bloom (May–June), while nutrient variability was lower during fruit-set and veraison. We also found fully mature leaf samples showed a lower variability in nutrient tissue content. Based on our results, sampling fully mature leafs from shoots remains the best practice. However, our results also indicate that tissue sampling later in the season might be a better practice, compared to the current practice of taking samples during June.}, number={11}, journal={AGRICULTURE-BASEL}, author={Freedman, Kyle Austin and Rana, Tekan Singh and Hoffmann, Mark}, year={2022}, month={Nov} }
 @article{rana_smith_hickey_hoffmann_2021, title={Leaf-tissue Nutrient Dynamics in Mature Muscadine Cultivars Carlos and Noble in Georgia and North Carolina}, volume={31}, ISSN={["1943-7714"]}, DOI={10.21273/HORTTECH04765-20}, abstractNote={More than 3000 acres of commercial muscadine (Vitis rotundifolia) vineyards exist in the southeastern United States. The muscadine wine industry is generating an economic impact of $1 billion in North Carolina alone. Muscadines have been cultivated since the 1800s, but muscadine vineyard fertilizer programs, tissue sampling, and nutrient sufficiency ranges continue to be based on anecdotal knowledge. While seasonal changes in tissue nutrient concentration are well documented in bunch grape (Vitis vinifera), questions remain about the seasonal and cultivar-dependent dynamics of muscadine leaf tissue nutrient concentrations. The aim of this study was to assess temporal and cultivar-related differences in tissue nutrient concentration of mature commercially grown muscadines. Leaf tissue nutrient concentration of the muscadine cultivars Carlos and Noble were assessed in three vineyards (Piedmont North Carolina, north Georgia, and south Georgia) at bloom, véraison, and postharvest in 2018 and 2019. Our results show that nitrogen (N), phosphorus (P), and manganese (Mn) were generally above the recommended sufficiency ranges, with calcium increasing over the season—and N, P, and potassium decreasing over the season. ‘Carlos’ had significantly higher levels of N and P, compared with ‘Noble’, while ‘Noble’ showed higher Mn concentration than ‘Carlos’. With this evaluation, we demonstrate the need for a modification in muscadine tissue nutrient sufficiency ranges that are based on cultivar and vine growth stage.}, number={3}, journal={HORTTECHNOLOGY}, author={Rana, Tekan S. and Smith, Erick D. and Hickey, Cain and Hoffmann, Mark}, year={2021}, month={Jun}, pages={280–290} }
 @article{rana_gu_yu_2020, title={Effect of Low Tunnels and Planting Dates on the Fruit Quality of Organic Day -Neutral Strawberries in High Tunnels in North Carolina}, volume={20}, ISSN={["1553-8621"]}, DOI={10.1080/15538362.2020.1774475}, abstractNote={ABSTRACT Fresh strawberry is in high demand because of the fruit’s unique flavor, taste, and high nutritional value. Berry quality is vital for fresh markets. Day-neutral strawberry varieties such as Albion and San Andreas have proven to produce a higher yield and better quality fruit than some short-day varieties. High tunnels (HT) and low tunnels (LT) are considered as good micro-environmental management options for the season extension of strawberries. However, the effects of LT inside HT on berry quality of day-neutral strawberries have not been reported. This 2-year study aimed to determine if LT and planting dates would affect the fruit quality of day-neutral strawberries in organically managed HT. The weight, size, color, texture, total soluble solids (TSS), and total titratable acidity (TTA) of berries were quantified. Planting dates and LT did not affect fruit quality variables except that fruit weight was reduced in LT in March and April. ‘Albion’ had larger, firmer fruit, and had higher TSS and TAA values than ‘San Andreas,’ except in samples collected in February. ‘San Andreas’ had more reddish and brighter fruit than ‘Albion.’ Although ‘Albion’ may produce better quality fruit than ‘San Andreas,’ both varieties would produce quality fruit for fresh markets in early spring. Including LT in HT did not benefit the fruit quality of organic day-neutral strawberries.}, journal={INTERNATIONAL JOURNAL OF FRUIT SCIENCE}, author={Rana, Tekan S. and Gu, Sanjun and Yu, Jianmei}, year={2020}, month={Sep}, pages={S1036–S1053} }
 @article{rana_gu_2020, title={Growth and Yield of Organic Day-neutral Strawberries in Low Tunnels inside High Tunnel in North Carolina}, volume={55}, ISSN={["2327-9834"]}, DOI={10.21273/HORTSCI14491-19}, abstractNote={North Carolina’s fresh strawberry has a $21.4 million economic value, which is primarily from short-day cultivars in the annual plasticulture system. Organic and off-season day-neutral strawberries have higher prices than the conventional, field-grown strawberries. There have been no published studies on suitable cultivars, transplanting dates, and additional winter protection methods for day-neutral strawberry production in high tunnels in North Carolina. The objective of this study was to examine the effect of low tunnels, planting dates, and cultivars on growth, yield, and season extension potential of day-neutral strawberries in high tunnels. Plugs of day-neutral cultivars Albion and San Andreas were either transplanted in raised beds covered with low tunnels (LT) or without low tunnels (control, NLT), inside high tunnels on the N.C. A&T State University Farm (Greensboro, NC) on two different planting dates, which were 1 Sept. (D1) and 29 Sept. (D2) of 2016, or 9 Sept. (D1) and 10 Oct. (D2) of 2017, respectively. A completely randomized design with split-split plots was used. LT did not significantly affect the total yield and plant phenology, but they promoted the first harvest by a week compared with NLT, which resulted in higher yield during the winter of both years. D1 promoted about 24 days of earlier harvest than D2. ‘Albion’ had an earlier bloom and harvest date (by 1 to 3 weeks and 2 to 3 weeks, respectively) than ‘San Andreas’. Strawberry yield was low in the fall season, but it started to increase from January, peaked in April, and decreased again in May. D1 increased the whole season’s marketable yield of ‘Albion’ (430.3 g/plant), compared with that of ‘San Andreas’ (330.9 g/plant). During the winter, ‘Albion’ had a higher yield than ‘San Andreas’. Our study indicates that LT inside HT might not significantly improve the plant growth, early harvest, or total yield. Planting dates had no consistent effect on yield. It was suggested that ‘Albion’ should be considered for high winter yields, and ‘San Andreas’ be a cultivar with high yields of the entire season in high tunnels.}, number={3}, journal={HORTSCIENCE}, author={Rana, Tekan S. and Gu, Sanjun}, year={2020}, month={Mar}, pages={336–343} }