Pub Date : 2024-05-01DOI: 10.21273/hortsci17438-23
Dominic B. Paonessa, Julie H. Campbell, William Secor, Benjamin L. Campbell
In 2020, the COVID-19 pandemic changed the way many businesses conducted business. Notably, regulations imposed by states impacted how green-industry firms sold their plants and landscape products. However, not all states implemented the same stringency of regulations. Using an online consumer survey implemented in Jan 2021, we examine the impact of varying regulation stringencies across five treatment groups (Michigan, and New York, and low, medium, and high stringency). We estimate the difference between 2020 and 2019 self-reported expenditures, in conjunction with propensity score matching to compare each treatment with the other treatments. Results indicate that, for the most part, states with greater stringency associated with their COVID regulations did not impact plant and landscape expenditures negatively between 2019 and 2020. However, Michigan consumers did spend significantly less than medium- and high-stringency states for landscape products. Michigan was one of only two states that put qualifications on green-industry firms, and it was the only state to list green-industry firms as nonessential. Also, New York consumers spent more than low-stringency states, and low-stringency states spent less than high-stringency states for plants. Furthermore, there were no differences in online expenditures between state treatment groups. From a policy perspective, regulation type (i.e., shutting down green-industry sectors as Michigan did) had varying impacts across product categories within the green industry.
{"title":"Impact of Varying Coronavirus Regulations on Green-industry Sales","authors":"Dominic B. Paonessa, Julie H. Campbell, William Secor, Benjamin L. Campbell","doi":"10.21273/hortsci17438-23","DOIUrl":"https://doi.org/10.21273/hortsci17438-23","url":null,"abstract":"In 2020, the COVID-19 pandemic changed the way many businesses conducted business. Notably, regulations imposed by states impacted how green-industry firms sold their plants and landscape products. However, not all states implemented the same stringency of regulations. Using an online consumer survey implemented in Jan 2021, we examine the impact of varying regulation stringencies across five treatment groups (Michigan, and New York, and low, medium, and high stringency). We estimate the difference between 2020 and 2019 self-reported expenditures, in conjunction with propensity score matching to compare each treatment with the other treatments. Results indicate that, for the most part, states with greater stringency associated with their COVID regulations did not impact plant and landscape expenditures negatively between 2019 and 2020. However, Michigan consumers did spend significantly less than medium- and high-stringency states for landscape products. Michigan was one of only two states that put qualifications on green-industry firms, and it was the only state to list green-industry firms as nonessential. Also, New York consumers spent more than low-stringency states, and low-stringency states spent less than high-stringency states for plants. Furthermore, there were no differences in online expenditures between state treatment groups. From a policy perspective, regulation type (i.e., shutting down green-industry sectors as Michigan did) had varying impacts across product categories within the green industry.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141052311","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 : 2024-05-01DOI: 10.21273/hortsci17743-24
Xiuxiu Sun, Peter A. Follett, Chang Shu, Zahra Yusufali, Jinhe Bai, Marisa Wall
The quality of Persian (Tahiti) lime (Citrus latifolia Tan.) fruit was determined following coating with carnauba wax and X-ray irradiation at doses suitable for disinfestation of quarantine pests. Fruit with or without carnauba wax coating were treated with irradiation doses of 0, 150, 300, or 450 Gy, and stored for 14 days at 13 °C and 6 days at 20 °C to simulate commercial transportation and marketing conditions from Hawaii to the continental United States. The fruit color, weight loss, total soluble solids (TSS) content, and titratable acidity (TA) were analyzed at 7, 14, and 14 + 6 days post irradiation. Wax coating significantly delayed fruit peel discoloration, and reduced fruit weight loss by more than 7% compared with the unwaxed controls. Irradiation did not affect ΔE of the peel for coated fruit at day 14 + 6. Irradiation with or without coating did not affect ΔE of flesh color, weight loss, TSS content, or TA. Wax coating combined with irradiation treatment of limes at doses ≤450 Gy ensured marketable visual quality and chemical composition while providing quarantine security.
{"title":"Effect of X-ray Irradiation and Carnauba Wax Coating on Quality of Lime (Citrus latifolia Tan.) Fruit","authors":"Xiuxiu Sun, Peter A. Follett, Chang Shu, Zahra Yusufali, Jinhe Bai, Marisa Wall","doi":"10.21273/hortsci17743-24","DOIUrl":"https://doi.org/10.21273/hortsci17743-24","url":null,"abstract":"The quality of Persian (Tahiti) lime (Citrus latifolia Tan.) fruit was determined following coating with carnauba wax and X-ray irradiation at doses suitable for disinfestation of quarantine pests. Fruit with or without carnauba wax coating were treated with irradiation doses of 0, 150, 300, or 450 Gy, and stored for 14 days at 13 °C and 6 days at 20 °C to simulate commercial transportation and marketing conditions from Hawaii to the continental United States. The fruit color, weight loss, total soluble solids (TSS) content, and titratable acidity (TA) were analyzed at 7, 14, and 14 + 6 days post irradiation. Wax coating significantly delayed fruit peel discoloration, and reduced fruit weight loss by more than 7% compared with the unwaxed controls. Irradiation did not affect ΔE of the peel for coated fruit at day 14 + 6. Irradiation with or without coating did not affect ΔE of flesh color, weight loss, TSS content, or TA. Wax coating combined with irradiation treatment of limes at doses ≤450 Gy ensured marketable visual quality and chemical composition while providing quarantine security.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141038129","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 : 2024-05-01DOI: 10.21273/hortsci17739-24
D. Selim, Abdel-Fattah Hassan Selim, R. Sami, Fadi Baakdah, Roqayah H. Kadi, A. Elhakem, U. Algopishi, Ruqaiah I. Bedaiwi, Heba S. A. EL-Desoky
This work assessed the alleviating effects of bacteria (Bacillus subtilis) and phosphorus as environmentally friendly materials on the cultivation of pepper plants in polluted soil with lead (Pb) in forms of PbSO4, and Pb(NO3)2 at rates of 0, 1000, 2000 and 3000 µg Pb/g soil. Pot experiments were conducted to study the growth parameters, some physiological factors, biochemical constituents, and yield attributes, as well as the tolerance index (TI), translocation factor (TF), bioconcentration factor (BCF), and health effects [daily intake of heavy metals (DIM), health risk index (HRI), and carcinogenic risk (CR)]. Increasing the Pb concentration of all Pb salt used in soil severely affected the plant vegetative growth parameters. In comparison with other Pb salt forms, Pb(NO3)2 salt had a strong inhibitory impact. Additionally, the photosynthetic pigments in leaves were negatively impacted by all Pb salt forms. The application of Pb in all salt forms led to changes in the leaf water deficit (LWD), osmotic pressure, and membrane integrity and decreased the total water content, relative water content (RWC), transpiration rate, and leaf succulence. Pollution with Pb salts considerably decreased the yield constituents and various chemical properties of pepper, more so in the presence of Pb nitrate than in the presence of Pb sulfate type. A comparison of the concentration of Pb presence of Pb nitrate was greatly increased than the Pb sulfate in the whole plants. The safe limit of 0.3 mg/kg was exceeded by the Pb concentration in pepper fruits (6.3 and 4.3 mg/kg) cultivated in Pb-contaminated soil [with Pb(NO3)2 and PbSO4, respectively]. Additionally, Pb sulfate had a greater detrimental effect on Pb uptake in several plant organs than other Pb salt forms. The TI of pepper plants treated with salt types was >60% with PbSO4 (75.6%), whereas it was <60% with Pb(NO3)2 (35.2%). The BCF values of pepper plants in the polluted Pb soils varied from 0.10 to 0.41, indicating a moderate accumulator plant. At every level of Pb contamination with all Pb salt types, the sequence of Pb TF values was as follows: roots (TFr) > shoots (TFsh) > fruits (TFf), with TF values < 1. When compared with TFr and TFsh, TFs for shoot to fruits (TFf) had the lowest values (range, 0.07–0.22). The DIM, HRI, and CR values of pepper plants revealed that the Pb of fruit of stressed pepper plants is within safe limits. In addition to reducing the detrimental effects of intolerable Pb levels (2000 and 3000 µg Pb/g soil) on the majority of the aforementioned characters, adding Bacillus bacteria as a bio-agent and phosphorus as a chemo-agent to Pb-polluted soils also stimulated growth, increased yield, controlled plant water relations, protected photosynthetic pigments, and sharply decreased the Pb accumulation in plant organs. The Bacillus bacteria application resulted in some superior characteristics, such as root length, leaf number, leaf length, leaf area, leaf area index, fresh biomass
{"title":"Physio-biochemical Behavior and Health Effects of Pepper Plants Subjected to Lead Stress and Their Responses to Remediating Agents as Microbial Activity and Phosphorus","authors":"D. Selim, Abdel-Fattah Hassan Selim, R. Sami, Fadi Baakdah, Roqayah H. Kadi, A. Elhakem, U. Algopishi, Ruqaiah I. Bedaiwi, Heba S. A. EL-Desoky","doi":"10.21273/hortsci17739-24","DOIUrl":"https://doi.org/10.21273/hortsci17739-24","url":null,"abstract":"This work assessed the alleviating effects of bacteria (Bacillus subtilis) and phosphorus as environmentally friendly materials on the cultivation of pepper plants in polluted soil with lead (Pb) in forms of PbSO4, and Pb(NO3)2 at rates of 0, 1000, 2000 and 3000 µg Pb/g soil. Pot experiments were conducted to study the growth parameters, some physiological factors, biochemical constituents, and yield attributes, as well as the tolerance index (TI), translocation factor (TF), bioconcentration factor (BCF), and health effects [daily intake of heavy metals (DIM), health risk index (HRI), and carcinogenic risk (CR)]. Increasing the Pb concentration of all Pb salt used in soil severely affected the plant vegetative growth parameters. In comparison with other Pb salt forms, Pb(NO3)2 salt had a strong inhibitory impact. Additionally, the photosynthetic pigments in leaves were negatively impacted by all Pb salt forms. The application of Pb in all salt forms led to changes in the leaf water deficit (LWD), osmotic pressure, and membrane integrity and decreased the total water content, relative water content (RWC), transpiration rate, and leaf succulence. Pollution with Pb salts considerably decreased the yield constituents and various chemical properties of pepper, more so in the presence of Pb nitrate than in the presence of Pb sulfate type. A comparison of the concentration of Pb presence of Pb nitrate was greatly increased than the Pb sulfate in the whole plants. The safe limit of 0.3 mg/kg was exceeded by the Pb concentration in pepper fruits (6.3 and 4.3 mg/kg) cultivated in Pb-contaminated soil [with Pb(NO3)2 and PbSO4, respectively]. Additionally, Pb sulfate had a greater detrimental effect on Pb uptake in several plant organs than other Pb salt forms. The TI of pepper plants treated with salt types was >60% with PbSO4 (75.6%), whereas it was <60% with Pb(NO3)2 (35.2%). The BCF values of pepper plants in the polluted Pb soils varied from 0.10 to 0.41, indicating a moderate accumulator plant. At every level of Pb contamination with all Pb salt types, the sequence of Pb TF values was as follows: roots (TFr) > shoots (TFsh) > fruits (TFf), with TF values < 1. When compared with TFr and TFsh, TFs for shoot to fruits (TFf) had the lowest values (range, 0.07–0.22). The DIM, HRI, and CR values of pepper plants revealed that the Pb of fruit of stressed pepper plants is within safe limits. In addition to reducing the detrimental effects of intolerable Pb levels (2000 and 3000 µg Pb/g soil) on the majority of the aforementioned characters, adding Bacillus bacteria as a bio-agent and phosphorus as a chemo-agent to Pb-polluted soils also stimulated growth, increased yield, controlled plant water relations, protected photosynthetic pigments, and sharply decreased the Pb accumulation in plant organs. The Bacillus bacteria application resulted in some superior characteristics, such as root length, leaf number, leaf length, leaf area, leaf area index, fresh biomass","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141036065","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 : 2024-05-01DOI: 10.21273/hortsci17631-23
Seon-Ok Kim, Na-Yeon Yoo, Yun-Jin Kim, Sin-Ae Park
We aimed to determine the energy expenditure, oxygen uptake, and exercise intensity of 10 care farming activities performed by adults. The study had a crossover experimental design. Participants performed 10 care farming activities for 5 minutes, including four plant- and three animal-mediated activities, and three other activities. Each participant wore a portable telemetric calorimeter during the activities, and oxygen uptake, heart rate, and exercise intensity were measured. Twenty-one adults (aged 31.5 ± 10.2 years) participated in our study. Energy expenditure, oxygen uptake, and exercise intensity differed significantly for each activity. The 10 care farming activities were regarded as light- to moderate-intensity activities. The exercise intensity, energy expenditure, and oxygen uptake for organizing a garden plot were significantly higher than those for other care farming activities. Cooking using harvests, interacting with dogs, and feeding rabbits had the lowest exercise intensity, energy expenditure, and oxygen uptake. Other activities, such as transplanting plants, harvesting, creating art, maintaining a garden, walking with a dog, and cleaning the farm, had moderate exercise intensity, energy expenditure, and oxygen uptake. Energy expenditure, oxygen uptake, and exercise intensity data could be useful when developing a care farming program suitable for the physical condition of participants in care farming interventions.
{"title":"Exercise Intensity Assessment of Care Farming Activities in Adults","authors":"Seon-Ok Kim, Na-Yeon Yoo, Yun-Jin Kim, Sin-Ae Park","doi":"10.21273/hortsci17631-23","DOIUrl":"https://doi.org/10.21273/hortsci17631-23","url":null,"abstract":"We aimed to determine the energy expenditure, oxygen uptake, and exercise intensity of 10 care farming activities performed by adults. The study had a crossover experimental design. Participants performed 10 care farming activities for 5 minutes, including four plant- and three animal-mediated activities, and three other activities. Each participant wore a portable telemetric calorimeter during the activities, and oxygen uptake, heart rate, and exercise intensity were measured. Twenty-one adults (aged 31.5 ± 10.2 years) participated in our study. Energy expenditure, oxygen uptake, and exercise intensity differed significantly for each activity. The 10 care farming activities were regarded as light- to moderate-intensity activities. The exercise intensity, energy expenditure, and oxygen uptake for organizing a garden plot were significantly higher than those for other care farming activities. Cooking using harvests, interacting with dogs, and feeding rabbits had the lowest exercise intensity, energy expenditure, and oxygen uptake. Other activities, such as transplanting plants, harvesting, creating art, maintaining a garden, walking with a dog, and cleaning the farm, had moderate exercise intensity, energy expenditure, and oxygen uptake. Energy expenditure, oxygen uptake, and exercise intensity data could be useful when developing a care farming program suitable for the physical condition of participants in care farming interventions.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141041343","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 : 2024-05-01DOI: 10.21273/hortsci17730-24
C. Jennings, T. Simmons, Madhav Parajuli, Kumuditha D. Hikkaduwa Epa Liyanage, F. Baysal-Gurel
The efficacy of the fungicide pydiflumetofen + difenoconazole (Postiva) was evaluated at varying application rates and intervals to control black spot disease (Diplocarpon rosae) in rose (Rosa spp. ‘Coral Drift’). Container-grown roses were arranged in a completely randomized design with five single-plant replications. Experiments were conducted under greenhouse and shade-house conditions (56% shade) in 2021/2022 and 2023. Black spot disease in roses was developed naturally. Pydiflumetofen + difenoconazole at 1.1 , 1.6, and 2.2 mL⋅L–1, and standard fungicide azoxystrobin + benzovindiflupyr (Mural) at 0.5⋅g L–1 were sprayed on foliage to runoff on a 2- or 4-week interval. Plants that were not treated with fungicide served as the controls. Plants were evaluated weekly for disease severity (0%–100% foliage affected) and defoliation (0%–100% defoliation). The season-long area under the disease progress curve (AUDPC) and area under the defoliation progress curve (AUDFC) were calculated for the evaluation period. Pydiflumetofen + difenoconazole reduced significantly black spot disease severity, AUDPC, defoliation, and AUDFC both in greenhouse and shade-house conditions compared with control plants, and was as effective as azoxystrobin + benzovindiflupyr. All the application rates and intervals of pydiflumetofen + difenoconazole were equally effective in reducing black spot severity and AUDPC. Our findings suggest that pydiflumetofen + difenoconazole at the lowest rate with the longest application interval is the most cost-effective, and has similar efficacy as treatments with higher rates and more frequent intervals.
{"title":"Effect of Fungicides and Application Intervals for the Control of Black Spot of Roses","authors":"C. Jennings, T. Simmons, Madhav Parajuli, Kumuditha D. Hikkaduwa Epa Liyanage, F. Baysal-Gurel","doi":"10.21273/hortsci17730-24","DOIUrl":"https://doi.org/10.21273/hortsci17730-24","url":null,"abstract":"The efficacy of the fungicide pydiflumetofen + difenoconazole (Postiva) was evaluated at varying application rates and intervals to control black spot disease (Diplocarpon rosae) in rose (Rosa spp. ‘Coral Drift’). Container-grown roses were arranged in a completely randomized design with five single-plant replications. Experiments were conducted under greenhouse and shade-house conditions (56% shade) in 2021/2022 and 2023. Black spot disease in roses was developed naturally. Pydiflumetofen + difenoconazole at 1.1 , 1.6, and 2.2 mL⋅L–1, and standard fungicide azoxystrobin + benzovindiflupyr (Mural) at 0.5⋅g L–1 were sprayed on foliage to runoff on a 2- or 4-week interval. Plants that were not treated with fungicide served as the controls. Plants were evaluated weekly for disease severity (0%–100% foliage affected) and defoliation (0%–100% defoliation). The season-long area under the disease progress curve (AUDPC) and area under the defoliation progress curve (AUDFC) were calculated for the evaluation period. Pydiflumetofen + difenoconazole reduced significantly black spot disease severity, AUDPC, defoliation, and AUDFC both in greenhouse and shade-house conditions compared with control plants, and was as effective as azoxystrobin + benzovindiflupyr. All the application rates and intervals of pydiflumetofen + difenoconazole were equally effective in reducing black spot severity and AUDPC. Our findings suggest that pydiflumetofen + difenoconazole at the lowest rate with the longest application interval is the most cost-effective, and has similar efficacy as treatments with higher rates and more frequent intervals.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141039670","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 : 2024-05-01DOI: 10.21273/hortsci17527-23
Jesse L. Carroll, S. Orr, Andrea Retano, Alexander D. Gregory, Scott B. Lukas, D. Bryla
Northern highbush blueberry (Vaccinium corymbosum L.) often requires frequent irrigation for commercial production, but irrigation is becoming increasingly challenging for many growers because of warmer and drier weather conditions, increased water regulations, and other water-use limitations. The purpose of this study was to develop improved methods of irrigation to prepare the industry more effectively against future water uncertainties. Treatments were applied for 2 years (2021 and 2022) and included a combination of weather-based or fixed irrigation schedules using continuous or pulse irrigation in a commercial field of ‘Draper’ blueberry in eastern Washington, USA. The soil at the site was a silt loam, and irrigation was applied using two laterals of drip tubing per row. Plants on a fixed schedule were irrigated for 12 to 13 hours per application (set by the grower), whereas those on a weather-based schedule were irrigated according to daily estimates of crop evapotranspiration (downloaded from an automated weather station). In both cases, irrigation was applied every 2 to 4 days as a single, continuous application or in 30- to 50-minute pulses every 2 hours (up to nine times per day) with the same amount of water as the continuous treatment. During the first year of the study, weather-based scheduling maintained greater stem water potentials in the plants and, on average, increased yield by 3.4 t⋅ha–1, berry weight by 0.14 g/berry, berry diameter by 0.4 mm, and fruit bud set by 4.3% when compared with fixed scheduling. Likewise, pulse irrigation maintained greater stem water potentials and, on average, increased berry weight and diameter by 0.10 g and 0.4 mm, respectively, fruit bud set by 3.3%, and canopy cover by 2.4% relative to continuous irrigation. Yield and canopy cover were unaffected by any treatment in the second year, which was likely a result of uncharacteristically cool, wet weather in the spring. However, weather-based scheduling continued to maintain greater stem water potentials and, when combined with pulse irrigation, increased berry weight and diameter by 3.7 g and 1.0 mm, respectively, relative to continuous irrigation on a fixed schedule. Pulse drip irrigation also increased fruit bud set by 5.1% during the second year. These results demonstrate the potential benefits of using weather-based scheduling and pulse drip in northern highbush blueberry, especially when the plants are grown on light-textured soils in hot, dry climates.
{"title":"Weather-based Scheduling and Pulse Drip Irrigation Increase Growth and Production of Northern Highbush Blueberry","authors":"Jesse L. Carroll, S. Orr, Andrea Retano, Alexander D. Gregory, Scott B. Lukas, D. Bryla","doi":"10.21273/hortsci17527-23","DOIUrl":"https://doi.org/10.21273/hortsci17527-23","url":null,"abstract":"Northern highbush blueberry (Vaccinium corymbosum L.) often requires frequent irrigation for commercial production, but irrigation is becoming increasingly challenging for many growers because of warmer and drier weather conditions, increased water regulations, and other water-use limitations. The purpose of this study was to develop improved methods of irrigation to prepare the industry more effectively against future water uncertainties. Treatments were applied for 2 years (2021 and 2022) and included a combination of weather-based or fixed irrigation schedules using continuous or pulse irrigation in a commercial field of ‘Draper’ blueberry in eastern Washington, USA. The soil at the site was a silt loam, and irrigation was applied using two laterals of drip tubing per row. Plants on a fixed schedule were irrigated for 12 to 13 hours per application (set by the grower), whereas those on a weather-based schedule were irrigated according to daily estimates of crop evapotranspiration (downloaded from an automated weather station). In both cases, irrigation was applied every 2 to 4 days as a single, continuous application or in 30- to 50-minute pulses every 2 hours (up to nine times per day) with the same amount of water as the continuous treatment. During the first year of the study, weather-based scheduling maintained greater stem water potentials in the plants and, on average, increased yield by 3.4 t⋅ha–1, berry weight by 0.14 g/berry, berry diameter by 0.4 mm, and fruit bud set by 4.3% when compared with fixed scheduling. Likewise, pulse irrigation maintained greater stem water potentials and, on average, increased berry weight and diameter by 0.10 g and 0.4 mm, respectively, fruit bud set by 3.3%, and canopy cover by 2.4% relative to continuous irrigation. Yield and canopy cover were unaffected by any treatment in the second year, which was likely a result of uncharacteristically cool, wet weather in the spring. However, weather-based scheduling continued to maintain greater stem water potentials and, when combined with pulse irrigation, increased berry weight and diameter by 3.7 g and 1.0 mm, respectively, relative to continuous irrigation on a fixed schedule. Pulse drip irrigation also increased fruit bud set by 5.1% during the second year. These results demonstrate the potential benefits of using weather-based scheduling and pulse drip in northern highbush blueberry, especially when the plants are grown on light-textured soils in hot, dry climates.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141046725","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 : 2024-05-01DOI: 10.21273/hortsci17642-23
Daniel Terlizzese, J. Lanoue, Xiuming Hao, Youbin Zheng
To effectively manage crop production in a greenhouse, it is essential to understand the natural light environment and physiological responses of the plants to light. This study investigated the dynamics of photosynthetic photon flux densities (PPFD) and light quality within the canopies of greenhouse-grown eggplant (Solanum melongena) and the photosynthetic capacities of leaves at different locations within the canopies. The light environment was quantified at 0.2-m intervals within (intra-canopy) and adjacent to (extra-canopy) the crop canopy on both sunny and cloudy days within a commercial greenhouse located in Leamington, Ontario, Canada. Our results indicated a linear decline in extra-canopy PPFD on both sunny and cloudy days, but an exponential decrease in intra-canopy PPFD. The intra-canopy PPFD decreased by 91% and 76% between 0 m and 0.4 m from the canopy apex on sunny and cloudy days, respectively. The lower canopy (0.6–1.2 m) light spectrum consisted largely of far-red light, equal amounts of red light and green light, with a lower percentage of blue light. Parameters derived from leaf-level light response curves indicated that the light-saturated net carbon exchange rate, light saturation point, and light compensation point decreased as the distance from canopy apex increased, whereas quantum yield was unaffected. Thus, leaves in the lower canopy were less efficient at using high PPFD, but they displayed no deterioration of photosynthetic machinery. Based solely on photosynthetic capabilities, leaves between 0 and 1.0 m from the canopy apex should not be removed to decrease the total plant sink strength.
{"title":"Light Environment and Photosynthetic Capacities of Leaves at Different Locations within Eggplant Canopies in a Greenhouse in Ontario, Canada","authors":"Daniel Terlizzese, J. Lanoue, Xiuming Hao, Youbin Zheng","doi":"10.21273/hortsci17642-23","DOIUrl":"https://doi.org/10.21273/hortsci17642-23","url":null,"abstract":"To effectively manage crop production in a greenhouse, it is essential to understand the natural light environment and physiological responses of the plants to light. This study investigated the dynamics of photosynthetic photon flux densities (PPFD) and light quality within the canopies of greenhouse-grown eggplant (Solanum melongena) and the photosynthetic capacities of leaves at different locations within the canopies. The light environment was quantified at 0.2-m intervals within (intra-canopy) and adjacent to (extra-canopy) the crop canopy on both sunny and cloudy days within a commercial greenhouse located in Leamington, Ontario, Canada. Our results indicated a linear decline in extra-canopy PPFD on both sunny and cloudy days, but an exponential decrease in intra-canopy PPFD. The intra-canopy PPFD decreased by 91% and 76% between 0 m and 0.4 m from the canopy apex on sunny and cloudy days, respectively. The lower canopy (0.6–1.2 m) light spectrum consisted largely of far-red light, equal amounts of red light and green light, with a lower percentage of blue light. Parameters derived from leaf-level light response curves indicated that the light-saturated net carbon exchange rate, light saturation point, and light compensation point decreased as the distance from canopy apex increased, whereas quantum yield was unaffected. Thus, leaves in the lower canopy were less efficient at using high PPFD, but they displayed no deterioration of photosynthetic machinery. Based solely on photosynthetic capabilities, leaves between 0 and 1.0 m from the canopy apex should not be removed to decrease the total plant sink strength.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141041873","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 : 2024-05-01DOI: 10.21273/hortsci17461-23
D. P. Leon-Chang, D. Bryla
Boron (B) is often deficient in many fruit crops, including blueberry (Vaccinium sp.). The objective of the present study was to evaluate different methods for applying B fertilizers to two commercial cultivars of northern highbush blueberry (V. corymbosum Earliblue and Aurora) in western Oregon, USA. Treatments included soil application of sodium tetraborate in early April (before bloom), foliar application of boric acid in late April (during bloom or petal fall), weekly fertigation with boric acid from April through July, and a control with no B. The plants were irrigated by drip, and the fertilizers were applied for two consecutive seasons at a total rate of 1.5 kg·ha−1 B per year. Each method of fertilizer application increased the concentration of B in the soil solution relative to the control, but fertigation was the only treatment that increased extractable soil B to the recommended level of 0.5 to 1.0 mg·kg−1 B. In terms of plant nutrition, foliar application of B was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation. Soil application of B, on the other hand, was relatively ineffective and, after 2 years, only increased the concentration of B in the leaves of ‘Earliblue’. Although leaf B levels were initially deficient at the site (<30 ppm B), none of the B application methods had any effect on yield, berry weight, fruit firmness, or titratable acidity of the fruit in either cultivar. However, foliar applied B resulted in higher concentrations of soluble solids in the fruit than no B or soil applied B in ‘Earliblue’, whereas B fertigation resulted in higher concentrations of soluble solids than soil applied B in ‘Aurora’. On the basis of these results, applying B by fertigation or as a foliar spray is recommended over the use of soil applications of B fertilizer in northern highbush blueberry.
{"title":"Applying Boron by Fertigation or as a Foliar Fertilizer Is More Effective than Soil Applications in Northern Highbush Blueberry","authors":"D. P. Leon-Chang, D. Bryla","doi":"10.21273/hortsci17461-23","DOIUrl":"https://doi.org/10.21273/hortsci17461-23","url":null,"abstract":"Boron (B) is often deficient in many fruit crops, including blueberry (Vaccinium sp.). The objective of the present study was to evaluate different methods for applying B fertilizers to two commercial cultivars of northern highbush blueberry (V. corymbosum Earliblue and Aurora) in western Oregon, USA. Treatments included soil application of sodium tetraborate in early April (before bloom), foliar application of boric acid in late April (during bloom or petal fall), weekly fertigation with boric acid from April through July, and a control with no B. The plants were irrigated by drip, and the fertilizers were applied for two consecutive seasons at a total rate of 1.5 kg·ha−1 B per year. Each method of fertilizer application increased the concentration of B in the soil solution relative to the control, but fertigation was the only treatment that increased extractable soil B to the recommended level of 0.5 to 1.0 mg·kg−1 B. In terms of plant nutrition, foliar application of B was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation. Soil application of B, on the other hand, was relatively ineffective and, after 2 years, only increased the concentration of B in the leaves of ‘Earliblue’. Although leaf B levels were initially deficient at the site (<30 ppm B), none of the B application methods had any effect on yield, berry weight, fruit firmness, or titratable acidity of the fruit in either cultivar. However, foliar applied B resulted in higher concentrations of soluble solids in the fruit than no B or soil applied B in ‘Earliblue’, whereas B fertigation resulted in higher concentrations of soluble solids than soil applied B in ‘Aurora’. On the basis of these results, applying B by fertigation or as a foliar spray is recommended over the use of soil applications of B fertilizer in northern highbush blueberry.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141054380","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 : 2024-05-01DOI: 10.21273/hortsci17669-23
Caroline Tardivo, L. Archer, Larissa Nunes, Fernando Alférez, Ute Albrecht
Huanglongbing (HLB), which is associated with the phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas), is a devastating disease that affects citrus trees worldwide. Because of the pervasiveness of the bacteria and psyllid vector, the disease is considered endemic in Florida. Although the effects of CLas on tree growth and physiology have been investigated for decades, most studies compared infected and noninfected trees under greenhouse conditions. This study used newly planted field-grown ‘Valencia’ sweet orange (Citrus sinensis) trees on two different rootstocks to monitor the distribution and accumulation of CLas in aboveground and belowground tissues following natural psyllid colonization and assess tree physiological responses and biomass reductions under HLB-endemic conditions. Trees were transplanted into the field with individual protective covers (IPCs), which are used to exclude psyllids and prevent infection. Openings were cut in the IPCs of half of the trees; to promote infection, these IPCs were temporarily removed during the main vegetative flushing period when psyllid populations were high. All trees that were exposed to psyllids became infected and displayed the symptoms typically associated with HLB. Throughout the study, higher levels of CLas were detected in the leaves compared with those in the fibrous roots. Trees that were not exposed to psyllids remained noninfected and healthy. After 18 months, a subset of trees was excavated to assess biomass differences between infected and noninfected trees. Infected trees had root system reductions of 37% and shoot system reductions of 20%, thereby significantly reducing the belowground-to-aboveground biomass ratio. Fibrous root loss was 49% and more severe than the loss of the rest of the root tissue. This study is the first to demonstrate the full extent of damage caused by CLas infection under natural HLB-endemic conditions. The results confirm previous observations that suggested fibrous root loss as one of the major consequences of infection and colonization with CLas. They also reinforce the benefits of using IPCs to prevent infection of young citrus trees during the first years of growth in the field.
{"title":"Root System Reductions of Grafted ‘Valencia’ Orange Trees Are More Extensive Than Aboveground Reductions after Natural Infection with Candidatus Liberibacter Asiaticus","authors":"Caroline Tardivo, L. Archer, Larissa Nunes, Fernando Alférez, Ute Albrecht","doi":"10.21273/hortsci17669-23","DOIUrl":"https://doi.org/10.21273/hortsci17669-23","url":null,"abstract":"Huanglongbing (HLB), which is associated with the phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas), is a devastating disease that affects citrus trees worldwide. Because of the pervasiveness of the bacteria and psyllid vector, the disease is considered endemic in Florida. Although the effects of CLas on tree growth and physiology have been investigated for decades, most studies compared infected and noninfected trees under greenhouse conditions. This study used newly planted field-grown ‘Valencia’ sweet orange (Citrus sinensis) trees on two different rootstocks to monitor the distribution and accumulation of CLas in aboveground and belowground tissues following natural psyllid colonization and assess tree physiological responses and biomass reductions under HLB-endemic conditions. Trees were transplanted into the field with individual protective covers (IPCs), which are used to exclude psyllids and prevent infection. Openings were cut in the IPCs of half of the trees; to promote infection, these IPCs were temporarily removed during the main vegetative flushing period when psyllid populations were high. All trees that were exposed to psyllids became infected and displayed the symptoms typically associated with HLB. Throughout the study, higher levels of CLas were detected in the leaves compared with those in the fibrous roots. Trees that were not exposed to psyllids remained noninfected and healthy. After 18 months, a subset of trees was excavated to assess biomass differences between infected and noninfected trees. Infected trees had root system reductions of 37% and shoot system reductions of 20%, thereby significantly reducing the belowground-to-aboveground biomass ratio. Fibrous root loss was 49% and more severe than the loss of the rest of the root tissue. This study is the first to demonstrate the full extent of damage caused by CLas infection under natural HLB-endemic conditions. The results confirm previous observations that suggested fibrous root loss as one of the major consequences of infection and colonization with CLas. They also reinforce the benefits of using IPCs to prevent infection of young citrus trees during the first years of growth in the field.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141024063","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 : 2024-05-01DOI: 10.21273/hortsci17724-24
Danielle D. Treadwell, Lincoln Zotarelli, P. Dittmar, Jeffrey G. Williamson, Marcio F R Resende, Ana D. Martin-Ryals, Carlos Messina, Christopher C. Gunter, Andrew D. Hanson, Simon P. Michaux
Like everything for the past 2 centuries, agriculture has depended increasingly on fossil fuel energy. Pressures to shift to renewable energy and changes in the fossil fuel industry are set to massively alter the energy landscape over the next 30 years. Two near-certainties are increased overall prices and/or decreased stability of energy supplies. The impacts of these upheavals on specialty crop production and consumption are unknowable in detail but the grand lines of what will likely change can be foreseen. This foresight can guide the research, extension, and teaching needed to successfully navigate a future very unlike the recent past. Major variables that will influence outcomes include energy use in fertilizer manufacture, in farm operations, and in haulage to centers of consumption. Taking six increasingly popular fruit and vegetable crops and the top two horticultural production states as examples, here we use simple proxies for the energy requirements (in gigajoules per ton of produce) of fertilizer, farm operations, and truck transport from Florida or California to New York to compare the relative sizes of these requirements. Trucking from California is the largest energy requirement in all cases, and three times larger than from Florida. As these energy requirements themselves are all fairly fixed, but in future will likely rise in price and/or be subject to interruptions and shortages, this pilot study points to two commonsense inferences: First, that fruit and vegetable production and consumption are set to reposition to more local/regional and seasonal patterns due to increasing expenses associated with fuel, and second, that coast-to-coast produce shipment by truck will become increasingly expensive and difficult.
{"title":"Transitioning Away from Fossil Fuels Will Drive Repositioning of Horticulture","authors":"Danielle D. Treadwell, Lincoln Zotarelli, P. Dittmar, Jeffrey G. Williamson, Marcio F R Resende, Ana D. Martin-Ryals, Carlos Messina, Christopher C. Gunter, Andrew D. Hanson, Simon P. Michaux","doi":"10.21273/hortsci17724-24","DOIUrl":"https://doi.org/10.21273/hortsci17724-24","url":null,"abstract":"Like everything for the past 2 centuries, agriculture has depended increasingly on fossil fuel energy. Pressures to shift to renewable energy and changes in the fossil fuel industry are set to massively alter the energy landscape over the next 30 years. Two near-certainties are increased overall prices and/or decreased stability of energy supplies. The impacts of these upheavals on specialty crop production and consumption are unknowable in detail but the grand lines of what will likely change can be foreseen. This foresight can guide the research, extension, and teaching needed to successfully navigate a future very unlike the recent past. Major variables that will influence outcomes include energy use in fertilizer manufacture, in farm operations, and in haulage to centers of consumption. Taking six increasingly popular fruit and vegetable crops and the top two horticultural production states as examples, here we use simple proxies for the energy requirements (in gigajoules per ton of produce) of fertilizer, farm operations, and truck transport from Florida or California to New York to compare the relative sizes of these requirements. Trucking from California is the largest energy requirement in all cases, and three times larger than from Florida. As these energy requirements themselves are all fairly fixed, but in future will likely rise in price and/or be subject to interruptions and shortages, this pilot study points to two commonsense inferences: First, that fruit and vegetable production and consumption are set to reposition to more local/regional and seasonal patterns due to increasing expenses associated with fuel, and second, that coast-to-coast produce shipment by truck will become increasingly expensive and difficult.","PeriodicalId":13140,"journal":{"name":"Hortscience","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141044847","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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