Browse

You are looking at 1 - 10 of 28,382 items for

  • All content x
Clear All
Open access

Paul W. Bosland and Danise Coon

Open access

Xuan Wei, Hayk Khachatryan and Alicia Rihn

In recent years, growers in the ornamental horticulture industry have experienced declining revenue and shrinking profit margins due to increased consumer spending captured by wholesale stores bypass, price competition at the retail level, as well as relatively low consumer demand. Maintaining cost-effective production practices is critical for nursery and greenhouse growers to stay profitable. However, a recent trend to impose more restrictive labeling polices on pesticide use (i.e., disclosing the use of neonicotinoids) may impact growers’ already tightening production costs. A better understanding of the cost structure and production decision-making can provide insights for profitable operation. Using a partial enterprise budgeting approach, this research aims to evaluate production costs and profitability for 20 individual greenhouse annual and perennial crop production systems. Three primary economic performance indicators (net income, gross margin, and profit margin) were calculated and a sensitivity analysis was conducted to account for potential risks in production. Our results suggest that production costs vary significantly among different crops, thus implying that producers may have different profitability levels depending on the combination of crops grown. Our partial enterprise budgeting estimates serve as a reference point and can assist producers with reducing costs in specific areas, and aids in selecting and adjusting crop combinations to maximize potential profits. Sensitivity analysis scenarios provide insights to producers for evaluation of their entire operations and aid in making decisions on adopting alternative practices.

Open access

Job Teixeira de Oliveira, Rubens Alves de Oliveira, Mario Puiatti, Paulo Teodoro and Rafael Montanari

The objective of this study was to evaluate whether the spatial variability of plant production components and the use of an irrigation and fertirrigation management system with controlled deficit affect the yield and incidence of garlic lateral shoot growing (LSG). An analysis of these data through statistical and geostatistical techniques made it possible to verify that the increase in yield is directly related to the height and diameter of the bulb and that the lateral shoot growing is directly related to the increase in yield. Lower water depths and lower nitrogen doses applied during clove differentiation imply a lower incidence of LSG, whereas increased irrigation and fertigation with nitrogen results in lower bulb volumes.

Open access

Andrés Javier Peña Quiñones, Melba Ruth Salazar Gutierrez and Gerrit Hoogenboom

A common problem for decision makers in selecting frost control options is uncertainty about the level of injury that can be caused by low temperatures. During the past few years, the concept of lethal temperature (LT) at which 10% of the bud population dies (LT10) has been used as an index for evaluating the vulnerability of flower buds to low temperature conditions. This concept has shown to be a useful tool for frost control decision-making. However, the current methods used to obtain LT values assume no spatial or temporal variability, which results in a high level of uncertainty. The goal of this study was to develop an approach that decreases the uncertainty based on the known effects of temperature on bud vulnerability. A growth chamber experiment was conducted to determine flower bud vulnerability to low temperature as a function of temperature. The results from this study showed that thermal time expressed in degree days could explain changes in floral bud development and vulnerability to frost injury. According to our findings, LT10 is a fully acceptable index for determining flower bud vulnerability to low temperatures in orchard crops. Based on this information, we found that among the five apple and cherry cultivars analyzed, ‘Gala’ is the least vulnerable to low temperature because it starts at the beginning of spring with a high level of hardiness and increases its vulnerability at a low rate. The approach described in this article may enhance decision-making certainty associated with the timing and methods to increase air temperature in orchards during low-temperature events to avoid frost damage.

Open access

Elisa Solis-Toapanta, Andrei Kirilenko and Celina Gómez

Social media platforms such as Reddit, centered on user-generated, anonymous discussions, can facilitate the exchange of information and resources across niche online communities known as “subreddits.” Using data mining tools and content analysis methods, our objectives were to identify recurring questions and characterize comment (“response”) accuracy from four subreddits focused on hydroponic indoor gardening (r/hydro, r/Hydroponics, r/UrbanFarming, and r/Aerogarden). A total of 1617 original posts (OPs) were classified into one of ten topics and 4891 primary responses were analyzed for accuracy. The three topics with the most OPs (production systems, plant lighting, and root-zone environment), which accounted for 50% of the total OPs, were subcategorized and inductively analyzed. Most posts in the analyzed subreddits related to confusion regarding the design and implementation of appropriate hydroponic production systems. In addition, misinformation about plant lighting is a major part of discussions about growing plants indoors. There are also knowledge gaps regarding nutrient solution management, particularly about fertilizer formulation, pH balance, and on the impact that solution temperature has on plant growth and development. In general, there were no differences among response accuracy for all topics included in our analysis. However, regardless of topic, responses for most OPs had less than 50% accuracy, which demonstrates that misinformation can be disseminated in social media platforms such as Reddit. As suggested by the results of this study, targeted, open access research and outreach efforts offer an opportunity to address knowledge gaps among consumers interested in indoor gardening.

Open access

Andre Luiz Biscaia Ribeiro da Silva, Joara Secchi Candian, Elizanilda Ramalho do Rego, Timothy Coolong and Bhabesh Dutta

The use of resistant cultivars against Xanthomonas campestris pv. campestris (Xcc) is considered a critical management practice for black rot (BR) management in cabbage (Brassica oleracea var. capitata). Although most studies that have evaluated resistance to BR were conducted in greenhouses without accounting for yield, there is a clear need to investigate cultivar performance under field conditions. The objectives of this study were to evaluate commercial cabbage cultivars for resistance to BR and determine yield and head quality under field conditions. Field experiments with eight cultivars (Acclaim, Bravo, Capture, Celebrate, Cheers, Melissa, Monterey, and TCA-549) were conducted in two cabbage growing seasons, Fall 2018 and Spring 2019. Fields were spray-inoculated with Xcc (3 × 105 cfu/mL) at 35 and 49 days after transplanting in Fall 2018 and Spring 2019, respectively. Cabbage BR severity was evaluated at weekly intervals starting from 7 days postinoculation (DPI) until harvest. Marketable and unmarketable yields and cabbage head quality were measured at harvest. Cabbage BR symptoms were detected in all tested cultivars for both growing seasons with initial symptoms observed as early as 28 and 21 DPI in Fall 2018 and Spring 2019, respectively. Severity of cabbage BR at harvest was significantly greater in Fall 2018 compared with Spring 2019, whereas marketable yield was significantly higher in Spring 2019 (45,169 lb/acre) compared with Fall 2018 (26,370 lb/acre). In both growing seasons, ‘TCA-549’ had the lowest severity of BR and ‘Melissa’ had the highest severity of BR. Area under the disease progress curve (AUDPC) was 175 and 13 for ‘TCA-549’ in Fall 2018 and Spring 2019, respectively. The AUDPC for ‘Melissa’ in Fall 2018 and Spring 2019 were 2376 and 905, respectively. Regardless of growing season, cabbage marketable yield was higher for ‘Acclaim’ (51,760 lb/acre) compared with all other cultivars; however, there was no significant difference between Acclaim and TCA-549 (42,934 lb/acre) for cabbage marketable yield. Cabbage marketable yield was the lowest for cultivars Melissa (18,275 lb/acre) and Capture (24,236 lb/acre). Overall, there was a significant correlation between BR disease severity and cabbage marketable and unmarketable yields. Increasing the BR severity decreased cabbage marketability due to an increase in unmarketable yields. Continued development of cultivar resistance to BR is important for cabbage production in the southeastern United States, given the favorable conditions for disease development. The use of cultivars with low susceptibility, pathogen-free seeds, crop rotation, and proper spraying programs should be considered the best management practice for BR disease.

Open access

Sheng Li, Feng Wu, Yongping Duan, Ariel Singerman and Zhengfei Guan

Citrus huanglongbing (HLB), or greening, is the most destructive citrus disease worldwide and is threatening the sustainability of the industry in major citrus-growing regions. Various treatments have been proposed in the literature to manage the disease. We review such literature and conduct an economic analysis based on the reported treatment effects on fruit yield and quality to identify cost-effective management strategies. Our results suggest that, among the treatments we reviewed, broad-spectrum insecticides provide the only cost-effective strategy for mitigating the impact of the disease. Our findings and discussion should help growers, policymakers, and other stakeholders make informed decisions in the search for effective, sustainable, and environmentally friendly treatments and policies against HLB.

Open access

Xu-Wen Jiang, Cheng-Ran Zhang, Wei-Hua Wang, Guang-Hai Xu and Hai-Yan Zhang

The effects of CaCl2, GA3, and H2O2 priming on Isatis indigotica Fort. seed germination characteristics, seedling growth parameters, and antioxidant enzyme activities under salt stress were investigated. NaCl had an adverse effect on the germination and seedling performance of I. indigotica. However, these three priming agents alleviated salt stress by increasing the germination percentage, improving seed vigor, accelerating germination velocity, and establishing strong seedlings. The optimal concentrations were 15 g/L for CaCl2, 0.2 g/L for GA3, and 40 mm for H2O2. Seed priming treatments enhanced the activities of antioxidant enzymes in seedlings, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), under a salt environment, which reduced the oxidative injury caused by salt. Seed priming is a promising technique that can enhance the ability of I. indigotica seed germination when salt is present.

Open access

Gina Fernandez, Jeremy Pattison, Penelope Perkins-Veazie, James R. Ballington, Elizabeth Clevinger, Rocco Schiavone, Sanjun Gu, Jayesh Samtani, Edgar Vinson, Amanda McWhirt and Jose Guillermo Chacón