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Cold tolerance was measured midwinter in a New Hampshire, USA, orchard collection of 33 peach and nectarine cultivars over 3 years using natural and artificial freezing methods. Flower bud survival and xylem and cambium hardiness were based on the inflection point from nonlinear regression, as well as comparisons of injury at about −20 °C. Flower bud hardiness was greatest in ‘BuenOs’, ‘Contender’, ‘Cresthaven’, ‘Redhaven’, and ‘Scarlet Rose’. The lowest hardiness occurred in ‘Brigantine’, ‘Desiree’, ‘Emeraude’, ‘Evelynn’, ‘Galaxy’, ‘Glenglo’, ‘Jade’, ‘PF5D’, ‘PF23’, ‘Silverglo’, ‘Spring Snow’, and ‘Sugar May’. Other cultivars had either intermediate or inconsistent year-to-year bud hardiness. Bud hardiness in 2021 was weakly correlated with bud hardiness in 2023, but neither were correlated with bud mortality in 2022 after a severe freeze. Cambial hardiness in one year was not correlated with hardiness in other years. ‘August Rose’, ‘BuenOs’, ‘Cresthaven’, ‘Desiree’, and ‘Silverglo’ had the hardiest cambium which was consistent from year to year. Xylem hardiness was greatest in ‘BuenOs’, ‘Contender’, ‘Desiree’, ‘John Boy’, ‘PF17’, ‘Redhaven’, ‘Silvergem’, and ‘TangOs’. Xylem injury was significantly correlated across years indicating that this tissue responds more consistently to midwinter freezing temperatures than flower buds and cambium.

Despite being a legume, snap bean (Phaseolus vulgaris L.) lacks nodulation genes, restricting its ability for nitrogen (N) fixation through rhizobia, making N fertilization essential for maximizing yields. However, conventional fertilizer application may lead to N losses due to a lack of synchronization between plant uptake and N availability. A promising option could be controlled-release fertilizers (CRFs), which can be custom-formulated to synchronize nutrient release with plant growth needs, promoting efficient resource use. Field studies were conducted at the North Florida Research and Education Center-Suwannee Valley (NFREC-SV) in Live Oak, FL, during the spring of 2021 and 2022. The experiments also investigated broadcasting and banding application methods of the University of Florida’s recommended N rate (112 kg·ha⁻¹). The experimental design comprised 10 treatments, including five N rates (0, 56, 112, 168, and 224 kg·ha⁻¹ N) and two fertilizer sources (ammonium nitrate and CRF), applied to ‘Caprice’ in a randomized complete block design with four replications. Results showed a significant yield improvement with N fertilization vs. the zero-N control. However, no yield increase was observed beyond 56 kg·ha⁻¹. This finding could be due to the residual N from a preceding peanut crop rotation in both years. No notable variation in quality metrics (pod length and width) occurred above the 56 kg·ha⁻¹ threshold. The results also revealed that the choice between conventional or CRF did not exert any statistically significant differences in snap bean yield. In addition, fertilizer broadcast and banding treatments yielded the same results.

The Salix genus of the Salicaceae family has advantages such as rapid initial growth, a high germination rate, and asexual reproduction; therefore, it is used as a short-rotation energy crop for biomass production. The National Institute of Forest Science created new interspecific hybrid cultivars with superior biomass production by artificially interbreeding Salix caprea L. and Salix gracilistyla Miq. Identifying these hybrids during the seedling stage is challenging because their separate reproductive and vegetative growth stages necessitate prolonged observation of their morphological characteristics. Consequently, a reliable identification method is required to overcome these limitations. This study aimed to develop nuclear DNA markers to distinguish between S. caprea, S. gracilistyla, and their interspecific hybrids. An evaluation of 35 nuclear simple-sequence repeat (nSSR) markers in the Salix genus revealed two markers that distinguish these parent species and their hybrids. A sequence analysis confirmed the presence of insertion-deletion (InDel) regions within the nSSR markers that differed between S. caprea and S. gracilistyla. To effectively identify hybrids, a primer set comprising the InDel region, which exhibited only interspecies differences and no intraspecies differences, was developed. The results of this study will facilitate the genetic resource management of interspecific hybrids between S. caprea and S. gracilistyla, thus allowing for early identification and improved management of hybrids.

Akebia trifoliata, as a new fruit, is becoming competitive and popular in the markets of eastern Asian countries, especially China, because of its nutritional value and health-promoting functions. To ultimately develop seedless varieties, germinating seeds of the A. trifoliata monoembryonic line ‘710’ with ∼1.5-cm-long roots were treated with five different concentrations of colchicine (0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) for four soaking periods (12, 24, 36, and 48 hours). Ploidy level assessments via both flow cytometry and karyotype analysis revealed some autotetraploids and chimeras in surviving seedlings treated with both 0.4% and 0.5% colchicine for 48 h, but the highest autotetraploid (33.3%) and chimera (19.0%) rates were observed in surviving seedlings treated with 0.3% colchicine for a 12-hour soaking period; no autotetraploids or chimeras were detected in plants treated with only water. In addition, we also found that autotetraploid plants usually presented broader and thicker leaves with larger stomas and epidermic cortical cells. Notably, no autotetraploid of A. trifoliata has been reported previously; therefore, both autotetraploids and chimeras are valuable breeding parents for autotriploid seedless varieties and ideal materials for further theoretical studies.

In the United States, the annual revenue attributable to tomato production is $1 billion. However, tomato production can cause negative environmental impacts, such as water pollution, often in the form of eutrophication-causing nutrient pollution. Hydroponic production can decrease excess nutrient leaching; however, optimization of nutrient management and cultivar choices could further decrease excess nutrient discharges. The objectives of this study were as follows: to evaluate and compare the responses of tomato growth characteristics, yield, and yield components to two nutrient management regimes (varying nutrient solution concentrations by growth stage and the use of a constant nutrient solution concentration from transplant to termination), and to analyze the effects of growth habits among six cultivars (Big Beef, Cherokee Purple, Heatmaster, Legend, Mountain Fresh Plus, and Tropic) on tomato yield and yield-correlated morphological characteristics. The nutrient management strategies were applied to tomato plants, and data regarding yield and related morphological characteristics were obtained. Data were analyzed using SAS PROC GLM. An analysis revealed no significant difference in the total fruit weight/plant between nutrient management regimes (P = 0.05); however, the mean fruit weight (164.26 g) and diameter (71.70 mm) were significantly greater (P < 0.0001) for plants that received the constant concentration nutrient regime. Indeterminate plants had a significantly greater (P < 0.0001) mean fruit weight (192.76 g) and mean fruit diameter (76.42 mm). Among cultivars, Big Beef had a significantly greater (P < 0.05) total fruit weight/plant (9.25 kg). Applying a constant nutrient concentration to indeterminate cultivars, particularly Big Beef and Cherokee Purple, improved the factors analyzed and could decrease negative environmental impacts while increasing profits of the producers.

Genetic resources are the foundation of American agriculture’s ongoing success—the diversity, security, health, and genetic integrity of these resources must be safeguarded. However, in contrast to other crops, protecting, managing, and using collections of woody landscape plant genetic resources present significant challenges. These include conservation of at-risk populations that have high genetic diversity, evaluation of taxa with an unknown potential to invade, and management of large specimens that have long generation times and often recalcitrant or difficult-to-store seeds. The wide diversity of taxa and the limited number of specialist curators and scholars present further challenges. Thus, effective collection, preservation, evaluation, and distribution of woody landscape plant germplasm require substantial and specialized resources. The most fundamental challenge is simple: too many built landscapes have low taxonomic diversity and are often dominated by a single taxon, or monoculture. In turn, these taxonomically and genetically depauperate landscapes are vulnerable to a host of biotic and abiotic threats and are less likely to provide ecosystem and societal services for which they were designed. To develop more resilient landscapes, there is an urgent need to expand taxonomic diversity, which requires the horticultural community to effectively acquire, curate, evaluate, distribute, and use diverse woody landscape plant genetic resources. The role of the US Department of Agriculture-Agricultural Research Service (USDA-ARS) National Plant Germplasm System (NPGS) Woody Landscape Plant Crop Germplasm Committee (WLPCGC) is to identify vulnerabilities and threats that compromise WLP crops in the United States and make recommendations for prioritization of germplasm acquisition, evaluation, research, and management priorities through regular interaction with stakeholders. Due to the breadth of genera and shifting plant genetic resource needs of the nursery industry, it is impractical to list specific threatened or priority genera in a broadly applicable crop vulnerability statement. Instead, the WLPCGC has identified themes of threats and vulnerabilities providing a foundation upon which to support prioritization as threats to specific genera emerge.

Fruit size and sugar content are key determinants of fruit quality, influenced by environmental factors and agronomic practices and sink strength provided by the genetic potential. Strawberry (Fragaria ×ananassa) produces fruits arranged in inflorescences, whose growth is affected by carbon competition between them. The competitive ability is termed as sink strength, which can be quantified as the potential growth rate under sufficient resource supply and/or no carbon competition among sinks, referred to as non-limiting conditions. Most previous studies did not observe potential growth, thereby failing to adequately evaluate sink strength and to assess the influence of environmental factors and agronomic practices on fruit growth. This study aimed to investigate the potential growth of strawberry fruits and analyze its sink strength dynamics. Non-limiting conditions were established by removing flowers to one fruit per inflorescence in a greenhouse experiment with plants grown in soil and given water and nutrients through drip irrigation. Fruits were harvested every 5 days from 5 to 55 days after anthesis (DAA), measuring the size, weight, and concentrations of major soluble carbohydrates in strawberry (sucrose, glucose, and fructose) and starch. Sink strength was represented by absolute growth rate based on fruit weight, and its components, sink size and sink activity, were represented by weight and relative growth rate, respectively. Fruit volume and weight showed a gradual linear increase at 5 DAA and then rapidly increased, following a single sigmoid curve between 30 and 55 DAA. Fruits primarily accumulated glucose and fructose during early growth, shifting to sucrose after 35 DAA. Starch concentration peaked at 5 DAA and then exponentially decreased. Sink strength exhibited a single peak between 40 DAA and 45 DAA. Sink strength gradually increased with sink size until 30 DAA, whereas sink activity significantly decreased until 30 DAA. Thereafter, sink strength and sink activity exhibited a peak, whereas sink size continued to increase. These results suggest that the major determinant of sink strength was sink size during early fruit growth, shifting to sink activity during late growth.

Interest in local foods, especially locally grown fruit, is increasing. High tunnel vegetable growers are strategically poised to meet this demand by growing specialty melons (Cucumis melo). Although specialty melons are commonly grown in high tunnels in other parts of the world, it is an uncommon practice in the midwestern United States. The objectives of this study were to evaluate 10 specialty melon cultivars for high tunnel production and measure fruit yield and internal quality. Fruit of the cultivar Eden’s Gem yielded the greatest number of marketable fruits per plant; however, these melons are small and have a loose cavity. Fruit of the cultivars Honey Orange and Divergent yielded the largest marketable fruit per plant with tighter cavities; however, the cavities were large. All cultivars had good to excellent internal quality in terms of sugar content. The production of specialty melons in the high tunnel was successful, resulting in the production of melons with good to excellent internal quality, and several yielded three to four marketable fruit per plant. Implementing a strong pest management plan for cucumber beetle (Diabrotica undecimpunctata howardi) and powdery mildew (Erysiphe cichoracearum, Sphaerotheca fuliginea) is recommended to prevent yield loss, especially in locations such as the Midwest, where cucumber beetles often vector bacterial wilt (Erwinia tracheiphila).

This review was conducted to synthesize current knowledge, learn producer and Extension specialist perspectives, and identify gaps in understanding of the role of soil health in sustaining production in high tunnel (HT) systems. This synthesis includes findings from scholarly resources related to soil health in HTs, including research and Extension-based literature, perspectives from experienced HT producers and technical assistance providers, and the direct observations of a broad network of university research and Extension personnel working with HTs. Findings are intended to identify knowledge gaps and additional research and Extension resource needs of greatest priority to the HT producer community and technical assistance providers that support them at the time of publication. A review of 68 research articles and 58 Extension resources was conducted. Focus group interviews were conducted with small groups of experienced HT farmers in four regions of the eastern half of the United States, with in-depth farm case studies conducted in individual farmers in three of these regions. Growers across regions identified soil fertility management, soilborne diseases, soil compaction, and lack of consistency of soil analyses specific to HTs as the greatest soil-related challenges to HT production. Research and resources for technical assistance providers on mitigation strategies to remediate yield-limiting HT soil conditions, such as excessive soil salinity and high pathogen populations, were also lacking. As such, process-based research on techniques such as leaching, soil steaming, solarization, and anaerobic soil disinfestation in tunnels that consider short- and long-term costs, benefits, and effects on soil and plant productivity should be prioritized in the future when considering the impact of HT production on soil health. Interviews also indicated a need for networking opportunities for technical assistance providers across agencies (e.g., Natural Resources Conservation Service, Extension, nongovernmental organizations). Despite a high and increasing rate of adoption, there is currently a lack of information about maintaining HT systems. Given that HTs play a critical and growing economic role for specialty crop growers throughout the eastern United States, comprehensive intervention across the research–Extension spectrum to sustain productivity in HT systems is recommended.

Cover crops have a long and significant history in Florida’s citrus industry. During the late 1800s and early 1900s, they were widely used to enhance soil quality, boost fertility, and manage pests; therefore, they served as a critical agricultural tool before the widespread adoption of synthetic fertilizers. However, during the middle of the 20th century, a decline in the use of cover crops occurred as synthetic fertilizers and chemical pest control methods became more prevalent. Despite this decline, a resurgence of interest in cover crops has occurred among Florida’s citrus growers. This renewed interest is driven by the urgent need to increase soil fertility while reducing inputs, particularly in the context of managing citrus groves affected by citrus greening [huanglongbing (HLB)], which is a devastating disease that threatens the viability of the citrus industry. Citrus greening has created a growing interest in the use of management practices that can help mitigate the increasing cost of inputs needed to manage the disease. This literature review delves into the historical use of cover crops in Florida’s citrus industry and highlights their early adoption and subsequent decline. Additionally, it examines current cover crop management practices and focuses on key components such as seed selection, planting techniques, and termination methods. Finally, this review discusses the challenges and limitations associated with integrating cover crops into modern citrus production systems.