Accurate prediction of pest and crop phenology is essential for optimizing integrated pest management (IPM) in cranberry production systems. Degree-day models are widely used to forecast insect development and crop phenology; however, few have been developed for cranberry insect pests. We developed and validated degree-day–based models for the blunt-nosed leafhopper, Limotettix vaccinii (Hemiptera: Cicadellidae), in relation to cranberry bloom phenology in New Jersey, USA. Multiyear field data collected from commercial cranberry beds between 2022 and 2024 were used to develop and optimize the models, whereas independent datasets collected from 289 beds over a 5-year period (2021–25) were used for validation. Phenological progression of both pest and crop was modeled using logistic functions driven by growing degree-day (GDDpest and GDDcrop, respectively), with optimized base temperatures and biofix dates. The optimal L. vaccinii model used a base temperature of 10 °C and a biofix corresponding to floodwater drawdown [day of year (DOY) 112], whereas the cranberry bloom model converged on a base temperature of 4.44 °C and a DOY 94 biofix. Developmental trajectories showed consistent biological patterns, with nymphal activity preceding bloom and adult emergence overlapping the later stages of bloom. Model integration revealed that 10% bloom occurred, on average, at 716 GDDcrop (DOY 160), by which time ∼70% of nymphal development had already been completed. Based on these dynamics, the optimal insecticide application window was identified between 195 GDDpest (DOY 144; 25% nymphal progression) and peak nymph abundance at 266 GDDpest (DOY 153; 50% progression), maximizing nymph suppression while minimizing pollinator exposure. These results demonstrate that empirically optimized degree-day models can effectively synchronize L. vaccinii management with cranberry crop phenology. This framework provides a practical decision support tool for cranberry IPM and highlights the importance of regional calibration of phenology models to local climatic conditions and management practices.
Bok choy ( Brassica rapa subsp. chinensis ) is increasingly produced in nutrient film technique (NFT) hydroponics, in which transplants are raised in a propagation medium that becomes a permanent part of the root zone. Whether that medium affects marketable yield, and through which traits, is not well established. We compared three propagation media (Oasis phenolic foam, peat plug, and rockwool) for bok choy ‘Little Shanghai’ in an NFT system, sampling at establishment (15 d after transplant) and market maturity (37 d). Marketable yield did not differ among media at harvest: shoot fresh weight averaged 289 to 331 g per plant, and shoot dry weight, whole-plant leaf area, Soil Plant Analysis Development (SPAD) chlorophyll index, and visual market quality likewise did not differ. Medium instead reshaped plant form. Root architecture diverged at establishment: Oasis built the largest root system and rockwool the thickest and most densely branched one; size traits no longer differed by harvest, whereas rockwool held a 31% to 81% higher root:shoot dry-mass ratio at both harvests, consistent with denser root tissue rather than a larger network. Rockwool also produced fewer, larger, more lamina-dominated leaves, whereas Oasis produced the most leaves and had a transient early-growth advantage; leaf number and leaf size offset one another. Stomatal conductance and transpiration did not differ at establishment but diverged at maturity ( g sw 0.24 vs. 0.13 mol·m −2 ·s −1 , Oasis vs. rockwool), with no difference in SPAD or leaf-to-air vapor pressure deficit. Medium accounted for 15% of multivariate phenotypic variation, separating rockwool along an axis of root allocation and tissue density but not along the axis carrying shoot fresh weight. Propagation medium is therefore a lever on root development and leaf form rather than on marketable yield: it can be chosen on cost and handling without a detectable yield penalty, although not without altering the leaf profile of the harvested head.
End-of-production (EOP) lighting, lighting applied for a short duration before harvest, is a strategy to potentially increase the quality of greenhouse-grown leafy greens; however, exact species-specific strategies to deploy lighting are needed. Therefore, we evaluated the effects of EOP light intensity, quality, and duration of application on the growth, morphology, photosystem II efficiency, and postharvest longevity of ‘Salanova ® Hydroponic Red Butter’ lettuce ( Lactuca sativa L.), ‘Astro’ arugula ( Eruca sativa Mill.), ‘Space’ spinach ( Spinacia oleracea L.), and ‘Amara’ mustard greens ( Brassica carinata A. Braun). Leafy greens were grown in a common greenhouse environment with a 16-hour photoperiod and daily light integral of 8.6 ± 1.2 mol·m −2 ·d −1 for lettuce and arugula, and 9.4 ± 3.0 mol·m −2 ·d −1 for spinach and mustard greens. Seven days, 3 days, or 1 day before harvest, an additional 0 (control), ∼100, 200, 400, or 600 µmol·m −2 ·s −1 photosynthetic photon flux density (PPFD) of broad-spectrum white light [17:40:43 red (R):green (G):blue (B)], or ∼200 µmol·m −2 ·s −1 PPFD R-B (53:1:46 R:G:B) light was provided to plants. Across all species, fresh mass generally increased with increasing EOP light intensity and duration, with the greatest fresh mass observed under ∼600 µmol·m −2 ·s −1 applied for 7 days before harvest. Photosystem II efficiency response was species dependent but was generally lower when light intensity was increased 1 or 3 days before harvest and recovered when light intensity increased 3 or 7 days before harvest. The visual quality of lettuce, spinach, and mustard greens was largely unaffected by EOP light, whereas arugula visual quality improved by increasing the duration of broad-spectrum EOP light when evaluated 1 week postharvest. These results provide insight on how to effectively leverage light intensity, quality, and duration at the EOP to improve the growth and postharvest longevity of hydroponic greenhouse-grown lettuce, arugula, spinach, and mustard greens.
Nutrient management for organic vegetable production in sandy soils is challenging because of low organic matter, poor nutrient retention, and high leaching potential. However, enhancing cover cropping and fertilization can play important roles in improving crop yield and quality. This 2-year study evaluated the impacts of five cover crop treatments and two fertilization approaches on the yield and quality of organic bok choy (Brassica rapa var. chinensis ), zucchini ( Cucurbita pepo ), and bell pepper ( Capsicum annuum ). Cover crop treatments consisted of the following: sunn hemp ( Crotalaria juncea ) monoculture (SH); bicultures of SH with brown-top millet ( Urochloa ramosa ) (SH+M) or sorghum sudangrass ( Sorghum bicolor × Sorghum sudanese ) (SH+SSG); a four-way mixture of SH, the two grass species, and cowpea ( Vigna unguiculata ) (4-way mix); and a weedy fallow control. The fertilization approaches included a preplant approach with all nitrogen incorporated during bed preparation using heat-processed poultry manure and organic fertilizer compared with an integrated approach with 50% of the nitrogen supply incorporated during bed preparation and the remaining 50% through in-season liquid fertilization. Preplant fertilization resulted in significantly higher vegetable yields (marketable and/or total yield) in both seasons except for bell pepper yield in season 2, while integrated fertilization exhibited some impacts on improving crop quality. Cover crops had a greater impact in the second season by enhancing zucchini yield and quality (e.g., higher soluble solids and ascorbic acid contents and total antioxidant capacity). Bok choy quality was mainly influenced by fertilization, whereas bell pepper quality was affected by cover crop–fertilization interactions. In season 1, the bell pepper soluble solids content was higher with preplant than integrated fertilization in SH+M and 4-way mix, with SH showing lower values than SH+M under preplant fertilization. In season 2, the bell pepper ascorbic acid content was greater in SH+M than weedy fallow under preplant fertilization, and integrated fertilization enhanced ascorbic acid content in SH and 4-way mix. These findings highlight the important role of cover cropping and fertilization approaches in overcoming nutrient management challenges in sandy soils to enhance organic vegetable yield and quality attributes.
Clematis L., one of the largest genera in the Ranunculaceae, comprises ∼300 species distributed worldwide, including 147 species (93 endemic) recorded in China (Wang and Bartholomew 2001; Wang and Li 2005). Valued for their diverse flower forms and colors, clematis are widely grown as ornamental climbers, with more than 400 cultivars in cultivation (Beutler 2016; Grey-Wilson 2000). In horticultural usage, the term blue encompasses a range of flower colors, including blue, violet-blue, and purple-blue hues. In our study, flower color is described according to the color chart of the Royal Horticultural Society (RHS 2015), and the sepals of ‘Yandang Blue’ are designated violet-blue (RHS 91A). This horticultural color designation does not imply a biochemically or spectrally defined “true-blue” pigmentation system. The use of blue in clematis cultivar names does not necessarily denote a spectrally defined true-blue phenotype; several commercially cultivated clematis described as blue are characterized horticulturally as violet-blue or related hues. Although clematis have been cultivated in China for decades, independent cultivar development by Chinese breeders progressed slowly, and several Chinese cultivars have only recently been released and registered internationally (Liu et al. 2024; Zhang et al. 2026). Clematis patens C. Morren & Decne. subsp. tientaiensis (M.Y. Fang) W.T. Wang is a deciduous climber from Zhejiang Province, East China, and typically bears white flowers (Wang and Bartholomew 2001). ‘Yandang Blue’ was selected from this subspecies at the Zhejiang Institute of Subtropical Crops, Wenzhou, China. Unlike the wild form, it produces large, violet-blue (RHS 91A) flowers, 10.56 to 16.03 cm in diameter, from May to June. The cultivar was registered with the RHS, the International Cultivar Registration Authority (ICRA) for Clematis 14 Apr 2021 (International Clematis Registrar, Wisley, UK).
