Pub Date : 2023-10-01DOI: 10.21273/hortsci17314-23
John Ertle, Chieri Kubota
Indoor vertical farms that grow lettuce commonly encounter tipburn, which is an environmental disorder caused by calcium (Ca) deficiency during the late head-forming stages of lettuce. Characterized by marginal leaf necrosis of young expanding leaves, tipburn reduces marketable yield because of the appearance of these necrotic lesions. Lowering the daily light integral (DLI) to slow the plant growth rate has been a widely practiced approach to avoid tipburn in lettuce, but it largely reduces the final yield. We assessed the effect of lowering the DLI only during the end of production, which is a critical time because it is when tipburn is typically observed. Lettuce plants of tipburn-sensitive cultivars Klee and Rex were grown under a tipburn-inducing condition in growth chambers. Sixteen days after transplanting, the DLI was varied to 100% (L100), 85% (L85), 70% (L70), or 55% (L55) of the original 17.4 mol⋅m −2 ⋅d −1 to grow the final 12 d. At harvest, tipburn severity was reduced by lowering the DLI, but the magnitude of reduction was cultivar-specific. For ‘Klee’, the lowest tipburn severity was found at L55 (8% ± 2.1% of leaves), but the severity was similar for all other DLI levels (33% ± 3.5% of leaves). For ‘Rex’, tipburn severity was highest in the control (L100; 14% ± 2.8% of leaves) but similar for all other DLI levels (2% ± 0.9% of leaves). Reducing the end-of-production DLI to 55% resulted in a linear decrease in yield by up to 22% and 26% for ‘Klee’ and ‘Rex’, respectively. When the increase in marketable yields and decrease in the electricity cost were considered, decreasing the end-of-production DLI yielded a profitable contribution only for ‘Klee’ (L55). For moderately tipburn-sensitive ‘Rex’, revenue losses attributable to the yield decrease were too large to justify this approach of end-of-production reduced DLI.
{"title":"Reduced Daily Light Integral at the End of Production Can Delay Tipburn Incidence with a Yield Penalty in Indoor Lettuce Production","authors":"John Ertle, Chieri Kubota","doi":"10.21273/hortsci17314-23","DOIUrl":"https://doi.org/10.21273/hortsci17314-23","url":null,"abstract":"Indoor vertical farms that grow lettuce commonly encounter tipburn, which is an environmental disorder caused by calcium (Ca) deficiency during the late head-forming stages of lettuce. Characterized by marginal leaf necrosis of young expanding leaves, tipburn reduces marketable yield because of the appearance of these necrotic lesions. Lowering the daily light integral (DLI) to slow the plant growth rate has been a widely practiced approach to avoid tipburn in lettuce, but it largely reduces the final yield. We assessed the effect of lowering the DLI only during the end of production, which is a critical time because it is when tipburn is typically observed. Lettuce plants of tipburn-sensitive cultivars Klee and Rex were grown under a tipburn-inducing condition in growth chambers. Sixteen days after transplanting, the DLI was varied to 100% (L100), 85% (L85), 70% (L70), or 55% (L55) of the original 17.4 mol⋅m −2 ⋅d −1 to grow the final 12 d. At harvest, tipburn severity was reduced by lowering the DLI, but the magnitude of reduction was cultivar-specific. For ‘Klee’, the lowest tipburn severity was found at L55 (8% ± 2.1% of leaves), but the severity was similar for all other DLI levels (33% ± 3.5% of leaves). For ‘Rex’, tipburn severity was highest in the control (L100; 14% ± 2.8% of leaves) but similar for all other DLI levels (2% ± 0.9% of leaves). Reducing the end-of-production DLI to 55% resulted in a linear decrease in yield by up to 22% and 26% for ‘Klee’ and ‘Rex’, respectively. When the increase in marketable yields and decrease in the electricity cost were considered, decreasing the end-of-production DLI yielded a profitable contribution only for ‘Klee’ (L55). For moderately tipburn-sensitive ‘Rex’, revenue losses attributable to the yield decrease were too large to justify this approach of end-of-production reduced DLI.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135275171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17220-23
Pradip Poudel, Leigh Whittinghill, Hideka Kobayashi, Shawn Lucas
Given the current urbanization context and rising interest in green roof systems, growing a high-value crop such as saffron crocus in green roof medium could be an opportunity to use the benefits of both the crop and the green roof system; the drainage, aeration, and sand-like texture of green roof media make it suited for saffron production, and the saffron market price could make green roof production commercially viable. Various factors, including plant diseases and planting depth, could affect saffron production. Therefore, this research was conducted to evaluate the effects of planting depth and biofungicide treatments using Bacillus subtilis on saffron production in a green roof system. A completely randomized factorial block design was used with planting depth (10 cm and 15 cm) and B. subtilis strain QST 713 biofungicide treatments (an untreated control, 15.6 × 10 9 cfu/L, and 31.2 × 10 9 cfu/L) as independent variables. In 2019, fresh flower yield, fresh stigma yield, and dry stigma yield were calculated during harvesting, and additional data on flower number, tepal length and width, stigma length, and harvest time were collected in 2020. All variables were analyzed using analysis of variance (ANOVA) with planting depth and biofungicide treatments as fixed effects using R. Fresh stigma yield and dry stigma yield were higher in the 10-cm planting depth in 2019. Results were opposite in 2020: flower number, fresh flower yield, fresh stigma yield, dry stigma yield, and harvest time were higher in the 15-cm planting depth than the 10-cm planting depth. B. subtilis treatments did not affect any studied variable in 2020, but in 2019, the higher level of fungicide treatment resulted in lower fresh flower yield and dry stigma yield. There was no effect of biofungicide treatment and planting depth on tepal length, tepal width, and stigma length in both years. This study showed that growing saffron crocus on green roofs is feasible and even resulted in higher yield than field production in many saffron-producing regions and countries. In addition, results indicated that shallow planting might be suitable for annual production, whereas deeper planting could be ideal for perennial production based on the objective. Our findings demonstrated the feasibility of saffron production in the green roof system and suggest further research to develop best management practices.
{"title":"Evaluating the Effects of Bacillus subtilis Treatment and Planting Depth on Saffron (Crocus sativus L.) Production in a Green Roof System","authors":"Pradip Poudel, Leigh Whittinghill, Hideka Kobayashi, Shawn Lucas","doi":"10.21273/hortsci17220-23","DOIUrl":"https://doi.org/10.21273/hortsci17220-23","url":null,"abstract":"Given the current urbanization context and rising interest in green roof systems, growing a high-value crop such as saffron crocus in green roof medium could be an opportunity to use the benefits of both the crop and the green roof system; the drainage, aeration, and sand-like texture of green roof media make it suited for saffron production, and the saffron market price could make green roof production commercially viable. Various factors, including plant diseases and planting depth, could affect saffron production. Therefore, this research was conducted to evaluate the effects of planting depth and biofungicide treatments using Bacillus subtilis on saffron production in a green roof system. A completely randomized factorial block design was used with planting depth (10 cm and 15 cm) and B. subtilis strain QST 713 biofungicide treatments (an untreated control, 15.6 × 10 9 cfu/L, and 31.2 × 10 9 cfu/L) as independent variables. In 2019, fresh flower yield, fresh stigma yield, and dry stigma yield were calculated during harvesting, and additional data on flower number, tepal length and width, stigma length, and harvest time were collected in 2020. All variables were analyzed using analysis of variance (ANOVA) with planting depth and biofungicide treatments as fixed effects using R. Fresh stigma yield and dry stigma yield were higher in the 10-cm planting depth in 2019. Results were opposite in 2020: flower number, fresh flower yield, fresh stigma yield, dry stigma yield, and harvest time were higher in the 15-cm planting depth than the 10-cm planting depth. B. subtilis treatments did not affect any studied variable in 2020, but in 2019, the higher level of fungicide treatment resulted in lower fresh flower yield and dry stigma yield. There was no effect of biofungicide treatment and planting depth on tepal length, tepal width, and stigma length in both years. This study showed that growing saffron crocus on green roofs is feasible and even resulted in higher yield than field production in many saffron-producing regions and countries. In addition, results indicated that shallow planting might be suitable for annual production, whereas deeper planting could be ideal for perennial production based on the objective. Our findings demonstrated the feasibility of saffron production in the green roof system and suggest further research to develop best management practices.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135324532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17249-23
P. Dash, B. Guo, D. Leskovar
Hot and humid conditions create challenges for tomato production under a controlled environment. Low tomato productivity is related to the lack of stress tolerance of existing cultivars and their ability to maximize fruit set and yield. The aim of this study was to evaluate the effectiveness of three management strategies, cultivar selection, grafting, and plant density, for the growth and production efficiency of organically grown hydroponic tomatoes under adverse environmental conditions in Qatar. The experiment used a split-split plot design with ‘Velocity F1’ and ‘Sigma F1’ as the main plot treatments and a factorial arrangement of grafting combinations and planting densities (3.5 and 5.5 plants/m2) as subplots. Tomato cultivar Velocity F1 grafted on Maxifort F1 resulted in greater vegetative growth and improved phenological attributes than nongrafted Velocity F1. Grafted ‘Velocity F1’ plants grown at 3.5 plants/m2 had an increase in leaf photosynthetic rates (18%), less transpiration loss (16%), and less electrolyte leakage (15%) while maintaining stomatal conductance and intercellular CO2 concentrations. At 9 weeks after transplanting, canopy growth was higher (24%) and flowering occurred earlier (3 days) with grafted ‘Velocity F1’ transplants than with nongrafted transplants. Higher fruit sets (20%), pollen viability (22%), and fewer flower drops (17%) were also observed for grafted ‘Velocity F1’ transplants than for nongrafted transplants. Marketable fruit yields were higher (26%) with grafted ‘Velocity F1’ grown at 3.5 plants/m2 than with nongrafted ‘Velocity F1’. Both grafted ‘Velocity F1’ and ‘Sigma F1’ fruits retained acceptable fruit color (L*, a*, b*, C*, °h), firmness, °Brix, titratable acidity, weight, and prolonged shelf life by 4 additional days than nongrafted ones. We conclude that grafted tomato ‘Velocity F1’ grown at a plant density of 3.5 plants/m2 was the best management strategy for enhancing seedlings quality, plant growth, and postharvest quality and alleviating abiotic stresses under this protected environment and hydroponic system.
{"title":"Optimizing Hydroponic Management Practices for Organically Grown Greenhouse Tomato under Abiotic Stress Conditions","authors":"P. Dash, B. Guo, D. Leskovar","doi":"10.21273/hortsci17249-23","DOIUrl":"https://doi.org/10.21273/hortsci17249-23","url":null,"abstract":"Hot and humid conditions create challenges for tomato production under a controlled environment. Low tomato productivity is related to the lack of stress tolerance of existing cultivars and their ability to maximize fruit set and yield. The aim of this study was to evaluate the effectiveness of three management strategies, cultivar selection, grafting, and plant density, for the growth and production efficiency of organically grown hydroponic tomatoes under adverse environmental conditions in Qatar. The experiment used a split-split plot design with ‘Velocity F1’ and ‘Sigma F1’ as the main plot treatments and a factorial arrangement of grafting combinations and planting densities (3.5 and 5.5 plants/m2) as subplots. Tomato cultivar Velocity F1 grafted on Maxifort F1 resulted in greater vegetative growth and improved phenological attributes than nongrafted Velocity F1. Grafted ‘Velocity F1’ plants grown at 3.5 plants/m2 had an increase in leaf photosynthetic rates (18%), less transpiration loss (16%), and less electrolyte leakage (15%) while maintaining stomatal conductance and intercellular CO2 concentrations. At 9 weeks after transplanting, canopy growth was higher (24%) and flowering occurred earlier (3 days) with grafted ‘Velocity F1’ transplants than with nongrafted transplants. Higher fruit sets (20%), pollen viability (22%), and fewer flower drops (17%) were also observed for grafted ‘Velocity F1’ transplants than for nongrafted transplants. Marketable fruit yields were higher (26%) with grafted ‘Velocity F1’ grown at 3.5 plants/m2 than with nongrafted ‘Velocity F1’. Both grafted ‘Velocity F1’ and ‘Sigma F1’ fruits retained acceptable fruit color (L*, a*, b*, C*, °h), firmness, °Brix, titratable acidity, weight, and prolonged shelf life by 4 additional days than nongrafted ones. We conclude that grafted tomato ‘Velocity F1’ grown at a plant density of 3.5 plants/m2 was the best management strategy for enhancing seedlings quality, plant growth, and postharvest quality and alleviating abiotic stresses under this protected environment and hydroponic system.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43224662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17218-23
Hyungmin Rho, Jung Su, Ha Seon Sim, Yu Hyun Moon, Ui Jeong Woo, Sung Kyeom Kim
We aimed to develop a more accurate transpiration model for cucumber ( Cucumis sativus L.) plants to optimize irrigation and nutrient usage in soilless greenhouse cultivation. Accurate modeling of transpiration in greenhouse-grown cucumbers is crucial for effective cultivation practices. Existing models have limitations that hinder their applicability. Therefore, this research focused on refining the modeling approach to address these limitations. To achieve this, a comprehensive methodology was employed. The actual transpiration rates of three cucumber plants were measured using a load cell, enabling crop fresh weight changes to be calculated. The transpiration model was developed by making specific corrections to the formula derived from the Penman-Monteith equation. In addition, the study investigated the relationship between transpiration rate and solar radiation (Rad) and vapor pressure deficit (VPD), identifying a nonlinear association between these variables. The transpiration model was adjusted to account for these nonlinear relationships and compensate for Rad and VPD. Comparative analysis between the actual and estimated transpiration rates demonstrated that the developed cucumber transpiration model reduced overestimation by 23.69%. Furthermore, the model exhibited higher coefficients of determination and root mean square error (RMSE) values than existing models, suggesting its superior accuracy in predicting transpiration rates. Implementing the transpiration model-based irrigation method demonstrated the potential for ∼21% nutrient savings compared with conventional irrigation practices. This finding highlights the practical applications of the developed model—accounting for a nonlinearity of Rad and VPD—in optimizing irrigation practices for greenhouse cucumber cultivation.
{"title":"Development of a Cucumber Transpiration Model Based on a Simplified Penman-Monteith Model in a Semi-closed Greenhouse","authors":"Hyungmin Rho, Jung Su, Ha Seon Sim, Yu Hyun Moon, Ui Jeong Woo, Sung Kyeom Kim","doi":"10.21273/hortsci17218-23","DOIUrl":"https://doi.org/10.21273/hortsci17218-23","url":null,"abstract":"We aimed to develop a more accurate transpiration model for cucumber ( Cucumis sativus L.) plants to optimize irrigation and nutrient usage in soilless greenhouse cultivation. Accurate modeling of transpiration in greenhouse-grown cucumbers is crucial for effective cultivation practices. Existing models have limitations that hinder their applicability. Therefore, this research focused on refining the modeling approach to address these limitations. To achieve this, a comprehensive methodology was employed. The actual transpiration rates of three cucumber plants were measured using a load cell, enabling crop fresh weight changes to be calculated. The transpiration model was developed by making specific corrections to the formula derived from the Penman-Monteith equation. In addition, the study investigated the relationship between transpiration rate and solar radiation (Rad) and vapor pressure deficit (VPD), identifying a nonlinear association between these variables. The transpiration model was adjusted to account for these nonlinear relationships and compensate for Rad and VPD. Comparative analysis between the actual and estimated transpiration rates demonstrated that the developed cucumber transpiration model reduced overestimation by 23.69%. Furthermore, the model exhibited higher coefficients of determination and root mean square error (RMSE) values than existing models, suggesting its superior accuracy in predicting transpiration rates. Implementing the transpiration model-based irrigation method demonstrated the potential for ∼21% nutrient savings compared with conventional irrigation practices. This finding highlights the practical applications of the developed model—accounting for a nonlinearity of Rad and VPD—in optimizing irrigation practices for greenhouse cucumber cultivation.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135275169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17341-23
Erika R. Wright, Kevin D. Chase, Caitlin Littlejohn, Amber Stiller, Samuel F. Ward
Scale insects are some of the most abundant and damaging pests of urban forests in North America. Despite their prevalence, scale insect emergence during the winter dormant season, which could contribute to their population growth and spread and thereby inform management, has not been thoroughly investigated. Crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a nonnative pest of a widely grown landscape tree, crapemyrtle ( Lagerstroemia spp.). Now present throughout the Southeast and Mid-Atlantic regions of the United States, CMBS has spread rapidly since its initial detection in Plano, TX, USA, in 2004. The contributions of year-round activity to the insect’s widespread abundance and economic importance are unclear. Here, after infesting crapemyrtles with known numbers of CMBS in Summer 2021, we recorded the presence or absence of CMBS immatures on infested trees from Autumn 2021 to late Winter 2022. We found that active nymphs occurred throughout the entirety of these colder seasons. Additionally, average CMBS density drastically increased from October to March, growing from 28 ± 10 SE insects per plant to 554 ± 133 SE, respectively. Our results highlight previously unknown aspects of year-round crawler emergence by CMBS, which could provide opportunities for landscape managers to use targeted winter applications of less harmful pesticides such as horticultural oils.
蚧虫是北美城市森林中最丰富和最具破坏性的害虫之一。尽管蚧虫普遍存在，但在冬季休眠季节出现蚧虫可能有助于其种群增长和扩散，从而为管理提供信息，但尚未得到充分调查。紫薇树皮鳞(CMBS)是一种广泛生长的景观树种紫薇(Lagerstroemia spp.)的外来害虫。自2004年在美国德克萨斯州普莱诺首次发现CMBS以来，它已迅速蔓延至美国东南部和大西洋中部地区。全年活动对这种昆虫的广泛数量和经济重要性的贡献尚不清楚。在2021年夏季用已知数量的CMBS感染紫薇后，我们记录了2021年秋季至2022年冬末受感染树木上CMBS未成熟树的存在或不存在。我们发现活跃的若虫出现在整个寒冷的季节。10 ~ 3月，平均虫密度由28±10 SE /株增加到554±133 SE /株。我们的研究结果突出了CMBS全年爬行动物出现的未知方面，这可能为景观管理者提供机会，以便有针对性地在冬季使用危害较小的农药，如园艺油。
{"title":"Winter Activity for Crapemyrtle Bark Scale, an Urban Landscape Pest","authors":"Erika R. Wright, Kevin D. Chase, Caitlin Littlejohn, Amber Stiller, Samuel F. Ward","doi":"10.21273/hortsci17341-23","DOIUrl":"https://doi.org/10.21273/hortsci17341-23","url":null,"abstract":"Scale insects are some of the most abundant and damaging pests of urban forests in North America. Despite their prevalence, scale insect emergence during the winter dormant season, which could contribute to their population growth and spread and thereby inform management, has not been thoroughly investigated. Crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is a nonnative pest of a widely grown landscape tree, crapemyrtle ( Lagerstroemia spp.). Now present throughout the Southeast and Mid-Atlantic regions of the United States, CMBS has spread rapidly since its initial detection in Plano, TX, USA, in 2004. The contributions of year-round activity to the insect’s widespread abundance and economic importance are unclear. Here, after infesting crapemyrtles with known numbers of CMBS in Summer 2021, we recorded the presence or absence of CMBS immatures on infested trees from Autumn 2021 to late Winter 2022. We found that active nymphs occurred throughout the entirety of these colder seasons. Additionally, average CMBS density drastically increased from October to March, growing from 28 ± 10 SE insects per plant to 554 ± 133 SE, respectively. Our results highlight previously unknown aspects of year-round crawler emergence by CMBS, which could provide opportunities for landscape managers to use targeted winter applications of less harmful pesticides such as horticultural oils.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135275172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17334-23
Kate M. Evans, Bruce H. Barritt, Bonnie S. Schonberg, Lisa J. Brutcher, Manoella Mendoza, Ines Hanrahan
{"title":"‘WA 64’ Apple","authors":"Kate M. Evans, Bruce H. Barritt, Bonnie S. Schonberg, Lisa J. Brutcher, Manoella Mendoza, Ines Hanrahan","doi":"10.21273/hortsci17334-23","DOIUrl":"https://doi.org/10.21273/hortsci17334-23","url":null,"abstract":"","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135323810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17324-23
Patrick Veazie, M. Seth Balance, Brian E. Whipker, Ka Yeon Jeong
Growers have been searching for alternative horticultural growing media components because of their desire to use sustainable resources. Biochar is a carbon-based material that has been evaluated for use as an alternative aggregate in peat-based soilless substrates. Additionally, silicon (Si) has been examined as a beneficial element to promote plant growth and plant quality in a variety of crops. However, there has been limited research regarding the interaction of biochar as an aggregate and Si in soilless substrates. This study aimed to determine the impact of Si and biochar on plant growth and nutrient uptake for greenhouse-cultivated hemp ( Cannabis sativa L.). Hemp plants were grown in one of 12 different substrate blends: with two rates of calcium silicate (CaSiO 3 ), two aggregate types of biochar (medium or coarse) or perlite, and aggregate percentages of 85% peat + 15% aggregate and 70% peat + 30% aggregate. The cannabinoid concentration, plant height, diameter, or total plant biomass were similar across all substrate blends after 12 weeks of growth. Additionally, the use of CaSiO 3 as a Si substrate amendment increased Si foliar concentrations, and the addition of biochar to peat-based mixes did not limit the Si availability for plant uptake. However, Si substrate amendments did not impact plant height, diameter, or total plant biomass. This suggests that the biochar tested during this study is suitable in peat-based substrates for C. sativa ‘BaOx’ production at rates up to 30% (by volume) in peat-based substrates with CaSiO 3 amendments.
{"title":"Comparison of Peat–Perlite-based and Peat–Biochar-based Substrates with Varying Rates of Calcium Silicate on Growth and Cannabinoid Production of Cannabis sativa ‘BaOx’","authors":"Patrick Veazie, M. Seth Balance, Brian E. Whipker, Ka Yeon Jeong","doi":"10.21273/hortsci17324-23","DOIUrl":"https://doi.org/10.21273/hortsci17324-23","url":null,"abstract":"Growers have been searching for alternative horticultural growing media components because of their desire to use sustainable resources. Biochar is a carbon-based material that has been evaluated for use as an alternative aggregate in peat-based soilless substrates. Additionally, silicon (Si) has been examined as a beneficial element to promote plant growth and plant quality in a variety of crops. However, there has been limited research regarding the interaction of biochar as an aggregate and Si in soilless substrates. This study aimed to determine the impact of Si and biochar on plant growth and nutrient uptake for greenhouse-cultivated hemp ( Cannabis sativa L.). Hemp plants were grown in one of 12 different substrate blends: with two rates of calcium silicate (CaSiO 3 ), two aggregate types of biochar (medium or coarse) or perlite, and aggregate percentages of 85% peat + 15% aggregate and 70% peat + 30% aggregate. The cannabinoid concentration, plant height, diameter, or total plant biomass were similar across all substrate blends after 12 weeks of growth. Additionally, the use of CaSiO 3 as a Si substrate amendment increased Si foliar concentrations, and the addition of biochar to peat-based mixes did not limit the Si availability for plant uptake. However, Si substrate amendments did not impact plant height, diameter, or total plant biomass. This suggests that the biochar tested during this study is suitable in peat-based substrates for C. sativa ‘BaOx’ production at rates up to 30% (by volume) in peat-based substrates with CaSiO 3 amendments.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135324533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17286-23
Maureen Thiessen, J. Fields, Damon Abdi, Jeffrey Beasley
Many greenhouse growers rely on peat-based soilless substrates to produce salable crops in a relatively short period of time. Peat-based substrate suppliers often incorporate additional organic materials such as wood fiber to extend peat supplies. Given the relative success of wood-based substrates, growing interest in other fiber materials such as sugarcane bagasse may provide similar benefits for substrate processers. The objective of this research was to evaluate substrate properties and the productivity of a short-term floriculture crop, Osteospermum ‘Bright Lights Purple’, in a commercially available peat-based substrate (PL) that has been amended with either commercially available wood fiber [Hydrafiber (HF)] or an aged sugarcane bagasse fiber (SCB). Thus, substrates consisting of PL amended with 15% or 30% HF or SCB were developed. Plants were fertigated weekly at rates of 100, 200, or 300 ppm N, respectively. Crop growth and fertility dynamics were assessed. Substrate shrinkage was greatest in the 30% bagasse blend but had minimal impact given the 2-month crop cycle. The incorporation of 15% and 30% SCB and HF produced slight changes in pH over a 9-week growth period, with HF generally raising pH and SCB generally lowering pH compared with the 100% PL, showing promise for bagasse in managing substrate pH where irrigation water has high pH and/or alkalinity. Substrate EC was initially reduced by blending SCB and, to a lesser extent, HF, but differences ceased to exist by the end of the experiment. Chlorophyll and blooms were abundant in all substrates and fertigation rates. Regardless of fertigation rate, 30% HF had the lowest growth index and shoot dry mass, and 30% SCB had the lowest root dry mass, although differences were not visually apparent. Foliar N concentrations were greatest in plants grown in the PL and SCB substrates and lowest in HF blends. Overall, growth and dry mass differences were minimal across substrate treatment and fertigation rate, and all plants were marketable with statistically similar shelf life. In conclusion, this research indicates the potential of using SCB as a substrate amendment for short-term crop systems in a similar manner as wood fiber.
{"title":"Sugarcane Bagasse Is an Effective Soilless Substrate Amendment in Quick-turn Osteospermum Production","authors":"Maureen Thiessen, J. Fields, Damon Abdi, Jeffrey Beasley","doi":"10.21273/hortsci17286-23","DOIUrl":"https://doi.org/10.21273/hortsci17286-23","url":null,"abstract":"Many greenhouse growers rely on peat-based soilless substrates to produce salable crops in a relatively short period of time. Peat-based substrate suppliers often incorporate additional organic materials such as wood fiber to extend peat supplies. Given the relative success of wood-based substrates, growing interest in other fiber materials such as sugarcane bagasse may provide similar benefits for substrate processers. The objective of this research was to evaluate substrate properties and the productivity of a short-term floriculture crop, Osteospermum ‘Bright Lights Purple’, in a commercially available peat-based substrate (PL) that has been amended with either commercially available wood fiber [Hydrafiber (HF)] or an aged sugarcane bagasse fiber (SCB). Thus, substrates consisting of PL amended with 15% or 30% HF or SCB were developed. Plants were fertigated weekly at rates of 100, 200, or 300 ppm N, respectively. Crop growth and fertility dynamics were assessed. Substrate shrinkage was greatest in the 30% bagasse blend but had minimal impact given the 2-month crop cycle. The incorporation of 15% and 30% SCB and HF produced slight changes in pH over a 9-week growth period, with HF generally raising pH and SCB generally lowering pH compared with the 100% PL, showing promise for bagasse in managing substrate pH where irrigation water has high pH and/or alkalinity. Substrate EC was initially reduced by blending SCB and, to a lesser extent, HF, but differences ceased to exist by the end of the experiment. Chlorophyll and blooms were abundant in all substrates and fertigation rates. Regardless of fertigation rate, 30% HF had the lowest growth index and shoot dry mass, and 30% SCB had the lowest root dry mass, although differences were not visually apparent. Foliar N concentrations were greatest in plants grown in the PL and SCB substrates and lowest in HF blends. Overall, growth and dry mass differences were minimal across substrate treatment and fertigation rate, and all plants were marketable with statistically similar shelf life. In conclusion, this research indicates the potential of using SCB as a substrate amendment for short-term crop systems in a similar manner as wood fiber.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41940286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17258-23
A. Kaur, Lu Zhang, Ming Yang, N. Maness, C. J. Graham, R. Kumari, Yanwei Sun, Srijana Panta, L. Ferguson
Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a member of the Juglandaceae family. During spring, pecan trees break their bud dormancy and produce new leaves and flowers. Carbohydrates stored in roots and shoots are thought to support the bloom and early vegetative growth during this time until new leaves start the full photosynthetic activity. Spring freeze is known for its damaging effects on pecan bud and flower growth and development. Pecan shoots with leaves and flowers from five scion–rootstock combinations were collected hours before and after a recent spring freeze (below 0 °C for 6 hours, 21 Apr 2021, Perkins, OK, USA). Morphologies of the leaf, bud, and catkin were visually observed, and the morphologies of the anther and pollen in paraffin sections were investigated by light microscopy. Soluble sugar and starch from bark and wood were analyzed using the anthrone reagent method. The Kanza–Mount showed the maximum damage to terminal leaves, buds, and catkins, whereas Maramec–Colby had the minimum damage only to leaves. Pollen grains were shrunk and reduced in number in the anthers in the protandrous Pawnee scions, whereas no pollen damage was observed in the protogynous Kanza scion. Furthermore, bark soluble sugar levels increased in all the scion–rootstock combinations after the freeze, which may indicate a physiological response to the cold stress. Overall, the extent of spring freeze damage of pecans is affected by the growth stage, types of scion and rootstock, and the scion–rootstock interactions. Furthermore, in addition to low temperature, scion–rootstock interactions also affected the starch and soluble sugar contents in wood and bark tissues.
{"title":"Evaluation of Natural Spring Freeze Tolerance of Five Pecan Scion–Rootstock Combinations","authors":"A. Kaur, Lu Zhang, Ming Yang, N. Maness, C. J. Graham, R. Kumari, Yanwei Sun, Srijana Panta, L. Ferguson","doi":"10.21273/hortsci17258-23","DOIUrl":"https://doi.org/10.21273/hortsci17258-23","url":null,"abstract":"Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a member of the Juglandaceae family. During spring, pecan trees break their bud dormancy and produce new leaves and flowers. Carbohydrates stored in roots and shoots are thought to support the bloom and early vegetative growth during this time until new leaves start the full photosynthetic activity. Spring freeze is known for its damaging effects on pecan bud and flower growth and development. Pecan shoots with leaves and flowers from five scion–rootstock combinations were collected hours before and after a recent spring freeze (below 0 °C for 6 hours, 21 Apr 2021, Perkins, OK, USA). Morphologies of the leaf, bud, and catkin were visually observed, and the morphologies of the anther and pollen in paraffin sections were investigated by light microscopy. Soluble sugar and starch from bark and wood were analyzed using the anthrone reagent method. The Kanza–Mount showed the maximum damage to terminal leaves, buds, and catkins, whereas Maramec–Colby had the minimum damage only to leaves. Pollen grains were shrunk and reduced in number in the anthers in the protandrous Pawnee scions, whereas no pollen damage was observed in the protogynous Kanza scion. Furthermore, bark soluble sugar levels increased in all the scion–rootstock combinations after the freeze, which may indicate a physiological response to the cold stress. Overall, the extent of spring freeze damage of pecans is affected by the growth stage, types of scion and rootstock, and the scion–rootstock interactions. Furthermore, in addition to low temperature, scion–rootstock interactions also affected the starch and soluble sugar contents in wood and bark tissues.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47413767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.21273/hortsci17254-23
Kelly M. Thomas, A. Blount, Gary W. Knox, Cheryl L. Mackowiak, L. Sollenberger
Ornamental rhizoma peanut (Arachis glabrata Benth.; ORP) is a low-maintenance groundcover for use in urban and residential landscapes. Despite its availability since 2002, consumer insights on ORP have never been assessed. Online surveys are readily accepted by academic researchers as a valuable research tool. An online survey was distributed to 5820 Floridians with the objective to assess the use and perceptions of ORP by consumers. A total of 907 survey responses were received. Most respondents identified themselves as home gardeners (89%), white (93%), female (75%), and over age 65 (60%). Out of several turfgrass alternative benefits, respondents most valued reducing herbicide/pesticide and fertilizer/water usage and preventing weed establishment (χ2 = 204, df = 6, P < 0.001). The ORP selection purchased by respondents was predominately unknown. Most preferred ORP to flower heavily and frequently and maintain a canopy height below 20 cm in the landscape with infrequent mowing. Survey data show there is a potentially large consumer demand for ORP in Florida, but product availability, branding, and consumer access and engagement with information sources require additional focus in the coming years.
{"title":"Ornamental Rhizoma Peanut: Perceptions and Use by Florida Consumers","authors":"Kelly M. Thomas, A. Blount, Gary W. Knox, Cheryl L. Mackowiak, L. Sollenberger","doi":"10.21273/hortsci17254-23","DOIUrl":"https://doi.org/10.21273/hortsci17254-23","url":null,"abstract":"Ornamental rhizoma peanut (Arachis glabrata Benth.; ORP) is a low-maintenance groundcover for use in urban and residential landscapes. Despite its availability since 2002, consumer insights on ORP have never been assessed. Online surveys are readily accepted by academic researchers as a valuable research tool. An online survey was distributed to 5820 Floridians with the objective to assess the use and perceptions of ORP by consumers. A total of 907 survey responses were received. Most respondents identified themselves as home gardeners (89%), white (93%), female (75%), and over age 65 (60%). Out of several turfgrass alternative benefits, respondents most valued reducing herbicide/pesticide and fertilizer/water usage and preventing weed establishment (χ2 = 204, df = 6, P < 0.001). The ORP selection purchased by respondents was predominately unknown. Most preferred ORP to flower heavily and frequently and maintain a canopy height below 20 cm in the landscape with infrequent mowing. Survey data show there is a potentially large consumer demand for ORP in Florida, but product availability, branding, and consumer access and engagement with information sources require additional focus in the coming years.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47391253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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