Mechanical stimulation to produce stable and high-quality crops under greenhouse conditions is a promising alternative to chemical growth retardants. However, plant tissue damage and the lack of full automatization have been major constraints for large-scale applications. We demonstrate the potential of automated, touch-less, directed air stream application systems to control the plant height and appearance of bellflower (Campanula ‘Merrybell’), creeping inchplant (Callisia repens), and tomato (Solanum lycopersicum ‘Romello’). Plants were cultivated under greenhouse conditions and exposed to regulated air stream stimuli by three different prototype systems. Air stream stimuli of all three prototype systems significantly reduced plant height of all three plant species. Bellflower plants showed a reduction of 24% and tomato plants showed reductions of 26% to 36% compared with the respective control plants. The degree of height growth inhibition in tomato was shown to be predominantly influenced by the stimulus intensity. An air pressure prototype system was successfully implemented in a horticultural company and the height of creeping inchplant could be sufficiently reduced by 20%, on average, throughout 1 year of the experiment compared with untreated controls. Overall, no plant tissue damage of plants treated with the air stream was visible, and no difference in the number of flowers of the bellflower plants treated with the air stream and of the untreated controls was observed.
Marc-André Sparke, Achim Wegscheider, Patrick Winterhagen, Ute Ruttensperger, Martin Hegele, and Jens Norbert Wünsche
Teresita D. Amore, Peter J. Toves, Joanne L. Imamura, Janice Y. Uchida, and Chris Kadooka
Michele R. Warmund, David H. Trinklein, Mark R. Ellersieck, and Reid J. Smeda
The use of dicamba and 2,4-D products on herbicide-tolerant crops has resulted in numerous cases of off-target movement and injury to sensitive plants, including tomato (Solanum lycopersicon L.). Two greenhouse studies were conducted to determine whether ‘Big Beef’ (‘BB’) or ‘Florida 91’ (‘FL’) tomato plants pretreated with an antitranspirant, including Moisture-Loc (ML) at 100 mL·L−1, TransFilm (TF) at 50 g·L−1, or Wilt-Pruf (WP) at 100 mL·L−1, mitigated injury from synthetic auxin herbicides. Dicamba or 2,4-D was applied at a rate corresponding to 1/200 of the manufacturer’s labeled rate of 0.56 kg ae/ha or 1.06 kg ae/ha, respectively. At 2 weeks after treatment (WAT), plants treated with ML or WP before either herbicide exhibited injury symptoms, but they were always less severe than those treated with the herbicide alone for both cultivars. However, shoot length measurements indicated that none of the antitranspirants consistently provided protection against herbicide injury at 2 WAT. By 12 WAT, ML or WP used before either herbicide increased the number of live reproductive organs compared with dicamba or 2,4-D alone for both cultivars. Floral abortion on tomato plants was also reduced when ML or WP was applied before an herbicide treatment by 12 WAT. Although WP and ML did not provide complete protection against synthetic auxin herbicide injury, the concept of using film-forming barriers may be useful in mitigating some of the short-term effects of drift on plants.
Rachel Leisso, Bridgid Jarrett, Katrina Mendrey, and Zachariah Miller
Codling moth (Cydia pomonella) is a major insect pest of apple (Malus domestica). If unmanaged, then codling moth can infest nearly all apples in an orchard, where the flesh-tunneling larva leave frass-laden tracks in the fruit. Insecticide-based management requires accurate application timing (typically based on adult moth and/or degree-day monitoring) and multiple spray applications. Both the season-long commitment to codling moth monitoring and management and limited familiarity with insecticides, application tools, and proper application procedures can prevent a small-scale or backyard grower from effectively limiting fruit damage. In addition, an increasing segment of growers is interested in nonchemical alternatives. Bagging fruitlets early in the season could be a simple and effective method of codling moth management for this subset of growers. At our research orchard in Corvallis, MT, we tested a method combining fruit thinning and bagging using plastic bags the first season and nylon bags the second season. Plastic bags reduced the incidence of codling moth damage to fruit from 34% to 10%, but european earwig (Forficula auricularia) frass, which was found in more than 50% of plastic-bagged apples, made harvesting the fruit unappealing. We tested nylon fruit bags during the second year of the study. These bags did not significantly reduce the incidence of codling moth. Both the soluble solids content and titratable acidity were higher in unbagged fruit during the second year of the study, whereas color measurements indicated bagged fruit were greener on the shaded side of the fruit. Failure of the nylon bags may have been attributable to eggs laid before bagging, eggs laid or larva burrowing through bagging, or improper bag application methods. Further research could assess whole-tree bags, the addition of rubber bands or twist ties when applying nylon bags, pretreatment of fruit with horticulture oil, and/or dipping nylon bags in kaolin clay before application; however, these steps add time and increase costs, which may discourage the small-scale fruit grower. Overall, results indicate that fruit bagging holds promise for codling moth management; however, further work is needed to optimize the methodology.
Bao-Zhong Yuan, Zhi-Long Bie, and Jie Sun
Muskmelon is a warm season cucurbit species that belongs to family Cucurbitaceae. We analyzed 2955 papers of global research on muskmelon (Cucumis melo L.) based on Web of Science from 1924 to 2021. Papers were mainly written in English (2766, 93.604%), from 7883 authors, 83 countries or regions, 1697 organizations, and published in 585 journals and book series. The top five journals were HortScience (334, 11.303%), Journal of the American Society for Horticultural Science (Proceedings of the American Society for Horticultural Science) (117, 3.959%), Scientia Horticulturae (109, 3.689%), Plant Disease (88, 2.978%), and Phytopathology (84, 2.843%), each of which published more than 84 papers. The top five countries or regions were the United States, PR China, Spain, Brazil, and Japan, which each published more than 168 papers. The top six organizations were U.S. Department of Agriculture Agricultural Research Service, Agricultural Research Organization, Texas A&M University, Universitat Politecnica de Valencia, University of California–Davis and Consejo Superior de Investigaciones Cientificas, each of which published more than 64 papers. The top five authors are G.D. Lester, J.D. McCreight, J. Garcia-Mas, K.M. Crosby, and T.J. Ng, who each published more than 26 papers. On the basis of the analysis of a network map of VOSviewer, there were cooperation among authors, organizations, and countries or regions. All keywords of muskmelon research were separated into eight clusters for different research topics. Visualizations offer exploratory information on the current state and indicate possible developments in the future. This work is also useful for students identifying graduate schools and researchers selecting journals.
Oleg Daugovish, Mark Gaskell, Miguel Ahumada, and Anna D. Howell
Increased productivity of recently developed primocane raspberry (Rubus idaeus) and blackberry (Rubus sp.) cultivars have been accompanied by dramatic improvements in fruit firmness, shape, size, color, and flavor. These traits have contributed to the establishment of these crops throughout California. In this study, we evaluated publically available raspberry and blackberry cultivars for fruit yields, postharvest quality, and production in response to pruning management, at two locations in the central coast of California. Among raspberries, ‘Imara’ and ‘Kweli’ were the highest yielding cultivars at both trial locations while ‘Kwanza’ produced 30% to 50% larger fruit, by weight, with postharvest shelf life superior to that of ‘Vintage’. Among blackberries, ‘Prime-Ark® 45’ was the top-yielding cultivar and had the largest fruit at both locations during both years. ‘Prime-Ark® 45’ and ‘Prime-Ark® Traveler’ had comparable weights after 13 days in cold storage in 2018, while in 2019 ‘Prime-Ark® 45’ and ‘APF 268T’ had comparable fruit weight. Greater and earlier fruit yields of both blackberries and raspberries were obtained with combined production from floricanes and primocanes compared with primocane production alone. However, increase in cane density in combined production can complicate management of pests, fertigation, and fruit harvest efficiency. With increased interest in primocane cultivars, the information generated in this study has provided new resources to guide successful production by small, independent, and direct-sale growers.
Tomohiro Jishi, Ryo Matsuda, and Kazuhiro Fujiwara
Cos lettuce was grown under different spectral photon flux density distribution (SPFD) change patterns with blue- and/or red light-emitting diode (LED) irradiation with a 24-hour cycle. Twelve treatments were designed with a combination of four relative SPFD (RSPFD) change patterns and three photosynthetic photon flux density (PPFD) levels. The RSPFD change patterns were as follows: BR/BR, simultaneous blue- and red-light irradiation (BR) for 24 h; R/BR, red-light monochromatic irradiation (R) for 12 h followed by 12 hours of BR; B/BR, blue-light monochromatic irradiation (B) for 12 hours followed by 12 hours of BR; and B/R, 12 hours of B followed by 12 hours of R. Each RSPFD change pattern was conducted at three daily average photosynthetic photon flux densities (PPFDave) of 50, 100, and 200 µmol·m−2·s−1. The RSPFD change patterns that included B (B/BR and B/R) resulted in elongated leaves. A low ratio of active phytochrome to total phytochrome under B was considered the reason for leaf elongation. Shoot dry weight was significantly greater under the RSPFD change patterns that included B when the PPFDave was 200 µmol·m−2·s−1. The leaf elongation caused by B would have increased the amount of light received and thereby promoted growth. However, excessive leaf elongation caused the plants to fall, and growth was not promoted under the RSPFD change patterns that included B when the PPFDave was 50 µmol·m−2·s−1. Thus, 12-hour B promoted growth under conditions in which leaf elongation leads to increases in the amount of light received.
Ruining Zhang, Hongxing Cao, Chengxu Sun, and Jerome Jeyakumar John Martin
The evaluation and identification of germplasm resources is an indispensable step in the breeding processes and have important roles in the selection and improvement of new varieties. This research intended to characterize coconut germplasm to determine the quantitative, qualitative, and morphological traits of the stem, leaf, and inflorescence and the fruit characteristics. Sixteen morphological and qualitative traits of 17 coconut (Cocos nucifera L.) germplasm resources from Hainan, China, were investigated to determine the characteristics and advantages of multiple germplasm lines to create the foundation for the cultivation and breeding of coconuts. The results of the correlation analysis, principal component analysis (PCA), and cluster analysis indicate a correlation between coconut germplasm factors and their contribution to coconut traits. The results revealed that stem girth at 0.2 m was the most obvious trait, along with the fruit flavor, edible rate, fat content, hole spacing, single fruit weight, and number of female flowers, which reflect most of the information regarding coconut traits and contribute to its value. The PCA and cluster analysis indicated that two high-yield and superior-quality sweet water dwarf coconut germplasms, named ‘15-19’ and ‘15-17’, were suitable for cultivation and production in Hainan, China. The results of this study act a far-reaching influence on the collection and utilization of coconut resources and have an impact on the development and progress of the coconut industry in China.
Derrick R. Stowell, J. Mark Fly, William E. Klingeman, Caula A. Beyl, Angela J. Wozencroft, Douglas L. Airhart, and P.J. Snodgrass
While horticultural therapy (HT) has a long history in the United States, the profession has not had the acceptance and growth that related fields, such as art, music, recreational, occupational, and physical therapies have experienced. The objective of this study was to identify the current challenges and opportunities of HT in the United States. Maximum variation sampling was used to select current and former members of the American Horticultural Therapy Association (AHTA) for interviews. A total of 27 participants were interviewed between Nov. 2019 and Jan. 2020 using semi-structured qualitative interviews by Zoom. The interviews revealed six themes: 1) current state of the profession, 2) AHTA operations/structure, 3) education/credentialing, 4) funding/job opportunities, 5) public awareness/networking, and 6) research. This paper will discuss the challenges and opportunities presented in the six themes and provide recommendations for the future growth of the HT profession.