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Open access

Bridget Bolt, Anna Baloh, Roberta Magnani, Marta Nosarzewski, Carlos Rodriguez López, and Robert Geneve

‘Crimson Cabernet’ grape (Vitis vinifera) seeds showed physiological dormancy and germinated at ∼60% after 60 days of chilling stratification. Fresh seeds harvested after physiological maturity and sown without drying failed to germinate after 30 days when sown on agar. In agar-sown fresh seeds cut at the distal seed end or intact seeds treated with gibberellic acid (GA), the seeds germinated at ∼20% after 30 days. The highest germination percentages after 30 days were 63% to 83% in fresh, agar-sown seeds that were cut and treated with GA at 5000 mg⋅L–1 regardless of stratification time. Similar results were seen in seeds allowed to dry before sowing. Seeds cut and treated with GA at 5000 mg⋅L–1 germinated at 79% after 30 days. However, dry seeds sown on germination paper showed lower germination after cutting and GA treatment compared with agar-sown seeds. The highest germination percentages after 30 days in dry, cut seeds on germination paper treated with GA at 2000 and 5000 mg⋅L–1 were 33% and 55%, respectively, compared with agar-sown seeds, which germinated at 76% and 79%, with the same treatments. Results from this study provide a system that reduces the need for chilling stratification for grape seed germination by using partial seedcoat removal and GA treatment.

Open access

Makayla Johnson, Tina Marie Waliczek, Coleman Etheredge, and Jennifer Campbell Bradley

During the past few years, Americans have experienced a wide variety of stressors, including political tensions, racial/civil unrest, and the coronavirus disease 2019 (COVID-19) pandemic. All of these have led to uncertainty within society. Chronic feelings of helplessness can lead to depression or feelings of hopelessness in those who perceive their situation as unchanging. The purpose of this study was to evaluate the impacts of gardening and outdoor activities during the COVID-19 pandemic on perceptions of hope, hopelessness, and levels of depression, stress, and anxiety. Participants of this study were recruited through online social media platforms such as Facebook and Instagram; 458 participants completed the 21-item Depression Anxiety and Stress Scale inventory as well as the Hope Scale. Our data indicated that individuals who self-reported themselves as gardeners had significantly more positive scores related to levels of stress, anxiety, and depression and a sense of hope. Furthermore, gardeners had lower levels of self-reported depression, anxiety, and stress when compared with those who did not identify themselves as gardeners. The gardeners also had a more positive outlook regarding hope for the future. Additionally, a significant positive correlation was found between the number of hours spent participating in gardening and a sense of hope, and a negative correlation was found between the number of hours gardening and stress levels. Similarly, there was a significant negative correlation between the number of hours spent participating in any outdoor activity and self-reported levels of stress, anxiety, or depression; however, there was a positive correlation between the number of hours spent participating in any outdoor activity and a sense of hope. Our data suggested that more hours spent outside gardening or participating in recreational activities led to less perceived stress, anxiety, and depression and greater levels of hope for the future.

Open access

Drew A. Wolter, Guy B. Kyser, and Bradley D. Hanson

Threespike goosegrass (Eleusine tristachya) is a difficult-to-control perennial grass of increasing concern for orchard production systems in the Central Valley of California, USA. This grass has a bunch-type growth habit when tillered, which can interfere with orchard operations, particularly nut pickup from the ground at harvest. From 2016 to 2019, herbicide efficacy on threespike goosegrass was evaluated in a walnut (Juglans regia) orchard in Chico, CA, USA; an almond (Prunus dulcis) orchard in Livingston, CA, USA; and a prune (Prunus domestica) orchard in Orland, CA, USA. At each location, two independent experiments were conducted to evaluate 12 preemergent (PRE) herbicide treatments and eight postemergent (POST) treatments over several years, for a total of 16 trials. PRE herbicides were applied in January according to the region’s typical winter orchard management practices. One treatment included an additional sequential application in March to extend residual activity later into the warm season when threespike goosegrass germinates or resumes growth. In separate studies, POST control of established stands of threespike goosegrass was evaluated in May and June of each year. Each trial was conducted in a randomized complete block design with four replications. Threespike goosegrass control was visually estimated monthly for 5 months after the PRE treatments or at weekly intervals for 5 weeks following POST treatments. The most effective PRE treatment was a sequential application of indaziflam in January, followed by a March application of pendimethalin, providing 90% or greater control of threespike goosegrass 5 months after treatment across all sites and all years. Of the POST treatments, the three graminicides outperformed the other treatments with 73% to 91% control overall sites and years at 5 weeks after treatment. Fluazifop had the highest control ratings (85% to 91%) among the graminicide herbicides but was not always statistically better than clethodim or sethoxydim (74% to 83% control). Glyphosate alone resulted in unacceptable control (33% to 51%) regardless of rates tested, experimental sites, or years. Together, these results confirm grower reports of poor glyphosate performance on threespike goosegrass but suggest that effective herbicide programs can be developed to manage threespike goosegrass using PRE herbicides and POST graminicides registered in California orchard crops.

Open access

Sandra B. Wilson, Robert L. Geneve, Frederick T. Davies, and Aaron J. Sotala

A mobile web application called PropG was developed for students to quickly access more than 270 glossary terms defined in a plant propagation textbook. The functionality and usefulness of the app was evaluated by 53 students enrolled in a semester-long online course in plant propagation. Means of pre- and post-test responses to 17 knowledge items showed students perceived a significant knowledge gain in the course for each of the subject categories evaluated. Most students agreed or strongly agreed this learning tool was organized and easy to navigate and would use it in the future. Since 2021, PropG received 153,645 total page views, 90,818 unique visits, and 17,216 returning visits, showing its widespread use in plant propagation.

Open access

Kristine R. Buckland, Cynthia M. Ocamb, Ann L. Rasmussen, and Lloyd L. Nackley

Widespread outbreaks of tomato powdery mildew (Leveillula taurica and Oidium neolycopersici) are problematic in fresh market tomato (Solanum lycopersicum) crops in western Oregon, USA. In western Oregon, fresh market tomatoes are frequently grown in greenhouses or high tunnels where conditions can promote diseases such as powdery mildew. Heightened concerns about worker safety limit the pesticides available for use in enclosed systems. We studied the efficacy of ultraviolet-C (UV-C) light applications under high-tunnel conditions compared with a standard fungicide program. Plants treated with UV-C had zero incidence of powdery mildew on all sample dates in the first trial. In trial 2, disease incidence was lower on UV-C treated plants than both grower standard and nontreated control early in the study while disease severity remained lower in UV-C than nontreated control and similar to grower standard treatment. Additional research is needed to optimize UV-C treatment intervals to minimize negative effects on plant growth and maximize powdery mildew control.

Open access

Lyn A. Gettys, Kyle L. Thayer, Joseph W. Sigmon, and Jennifer H. Bishop

Most lake, canal, and pond management programs in the United States use herbicides labeled for aquatic use because many of these products, which are registered by the US Environmental Protection Agency, are relatively inexpensive and can effectively control undesirable plants without excessive damage to desirable species. Managers of these resources have expressed an interest in alternative methods for aquatic weed control that could reduce the use of traditional synthetic herbicides. We studied the effects of acetic acid and d-limonene on growth of the invasive aquatic species rotala (Rotala rotundifolia) and crested floatingheart (Nymphoides cristata), as well as on the native wetland plants spatterdock (Nuphar advena) and giant bulrush (Schoenoplectus californicus). We applied acetic acid and d-limonene (alone and in combination) once as foliar treatments to healthy plants, then grew out the plants for 8 weeks after treatment to observe damage resulting from treatments. We also evaluated diquat dibromide at three concentrations as “industry-standard” synthetic treatments for comparison. A 0.22% concentration of diquat dibromide eliminated most or all vegetation of rotala, crested floatingheart, and giant bulrush, but was much less damaging to spatterdock. Single-product applications of acetic acid or d-limonene had little effect on any of the four species evaluated. Some combinations of acetic acid and d-limonene provided acceptable control of rotala and selectivity on spatterdock and giant bulrush, but no treatments reduced crested floatingheart growth by more than 40%. Treating rotala with acetic acid and d-limonene instead of diquat dibromide would result in a 25-fold increase in material costs, which would make this option unaffordable for most aquatic system managers.

Open access

Travis W. Shaddox, J. Bryan Unruh, Mark E. Johnson, Clark D. Brown, and Greg Stacey

Integrated pest management (IPM) is an important component of golf course maintenance and includes conventional chemical pesticide use as well as nonchemical cultural management practices. Determining how frequent pest management practices are used on golf courses is critical when developing educational and outreach programs. The objective of this study was to determine the frequency of pest management practices and pesticide mixing and storage facilities on US golf courses. A survey was sent to 14,033 operational US golf facilities with 10% responding. Reliance on all conventional chemical pesticides increased from 2015 to 2021. The reliance on biological control products declined to 14% and reliance on the nonpesticide practice of using plant growth regulators remained equivalent to 2015. The most common pest management practices included monitoring weather patterns and scouting for pests, with 93% of golf facilities reporting the use of both. The use of written IPM and pesticide application plans increased from 44% to 63% of golf facilities between 2015 and 2021, respectively. Generally, mixing and storage facilities remained unchanged from 2015 to 2021. US golf facilities continue to use nonchemical pest management practices, but reliance on chemical pesticides has increased.

Open access

Chesney McOmber, Christine J. Kirchhoff, Yan Zhuang, and Rosa E. Raudales

Increasing demand on agricultural water resources have caused a greater need for the use of municipal recycled wastewater (MRW) globally. However, in the United States, greenhouse growers have been slow to use it in their greenhouse operations. In this study, we seek to understand the factors that motivate and limit use of MRW among US growers. Using national survey data from 2019 through 2020, we developed a logistic regression model to understand the many factors influencing growers’ willingness to use MRW on food crops. We find that MRW quality is a primary concern and that growers’ willingness to use MRW is shaped by their direct and indirect knowledge of MRW, garnered from their own and others’ experiences using it. Given these findings, improving adoption of MRW requires collective experiential learning opportunities that gather target audiences with educators, policymakers, end users, and local authorities to simultaneously provide hands-on experience tailored to growers’ particular knowledge and concerns with feedback from peers.

Open access

Irvan Prawira Julius Jioe, Ching-Chang Shiesh, and Huey-Ling Lin

Papaya milk, a mixture of papaya pulp and dairy milk, is one of the most popular beverages in Taiwan. However, the enzymes present in papaya can cause accumulation of hydrophobic amino acids, resulting in a bitter taste of papaya milk. Thus, it is important to select papaya cultivars without the potential to form the bitter taste, but it is difficult to select these papaya cultivars using a sensory test. The purpose of this research was to investigate the relationship between the intensity of the bitterness with the contents of proteins and free amino acids. The results indicated that neither milk nor papaya alone tastes bitter. Heating the milk or the papaya before mixing and mixing only papaya latex with milk confirmed that an enzyme in papaya causes the bitter taste in papaya milk. The intensity of bitterness positively correlated with the contents of total soluble protein, free amino acids and the phenylalanine and tyrosine/tryptophan contents. Analyses using different papaya accessions in different seasons showed that tyrosine/tryptophan (r = 0.613***) and phenylalanine (r = 0.612***) correlate more strongly with bitterness intensity than the total soluble protein (r = 0.258*) or free amino acids (r = 0.38**). In this drink, milk provides the substrates to form the bitter substances, but the enzymes in the papaya are needed for the reaction to occur. The levels of the amino acids phenylalanine and tyrosine/tryptophan showed the highest correlation with the intensity of bitterness.