Browsing by Author "Jarrett, Bridgid"

Now showing 1 - 6 of 6

Bagging Apple Fruit for Codling Moth Control in Western Montana
(American Society for Horticultural Science, 2021-08) Leisso, Rachel S.; Jarrett, Bridgid; Mendrey, Katrina; Miller, Zachariah J.
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.
Fresh haskap berry postharvest quality characteristics and storage life
(Canadian Science Publishing, 2021-11) Leisso, Rachel S.; Jarrett, Bridgid; Richter, Rebecca; Miller, Zachariah J.
Haskap (Lonicera caerulea L.) is a relatively new berry crop in North America, and little research exists regarding its postharvest storage characteristics or storage life. Postharvest changes in berry quality, and principal factors limiting storage life at 1.1 °C and 95% relative humidity, were evaluated up to 14 days for three cultivars in 2019 and up to 28 days for six cultivars in 2020. Containerized berries were periodically assessed for soluble solids content (SSC), skin rupture force (SRF) (both 2019 and 2020) and flesh firmness, titratable acidity (TA), and Brix/acid ratio (B/A) (2020 only). External appearance was also evaluated both years, revealing berry shrivel as the primary factor negatively impacting visual appeal, followed distantly by low incidence of spoilage later in storage. All cultivars exhibited relatively constant postharvest SSC and decreasing SRF, flesh firmness, and TA (resulting in increasing B/A ratio). Postharvest quality differed slightly between years; relative SRF was consistent among cultivars while SSC was not. Some cultivars had a portion of shriveled berries at harvest, pointing to a need for cultivar-specific harvest indices. Mean days to slight shrivel for individual berries varied among cultivars evaluated, ranging from 7.5–21.9 d postharvest, with mean weight loss ranging from 1.2%–1.6% at this stage. Combined with group marketability estimates — set at a threshold of 10% severely shriveled berries — we estimate a storage life of 7–10 d for fresh haskaps. Additional research is needed to delineate maturation physiology and optimize harvest timing.
Haskap maturity stages and their influence on postharvest berry quality
(Canadian Science Publishing, 2022-06) Leisso, Rachel S.; Jarrett, Bridgid; Richter, Rebecca; Miller, Zachariah J.
Limited information is available regarding haskap berry maturity and corresponding postharvest characteristics. We assessed detached berry quality, respiration rate, and ethylene production at five stages of maturity and compared postharvest storage influence on berries harvested at half-blue and softening stages. Ethylene’s increase at successive stages suggests its involvement with berry maturation, but concomitant respiration does not support classifying haskap ripening as climacteric. Results indicate harvesting at the less mature half-blue stage is not recommended, as berries had lower fresh weight and inferior quality relative to those harvested at the softening stage, both at harvest and following 14 d storage.
Haskap Preharvest Fruit Drop and Stop-drop Treatment Testing
(American Society for Horticultural Science, 2021-12) Leisso, Rachel S.; Jarrett, Bridgid; Miller, Zachariah J.
Haskap (Lonicera caerulea), also known as honeyberry, is a relatively new fruit crop in North America. To date, most academic activity and research in North America involving haskap has focused on cultivar development and health benefits, with relatively few field experiments providing information to guide field planning and harvest management for the recently released cultivars. In 2020, we documented preharvest fruit drop (PHFD) rates for 15 haskap cultivars planted in a randomized block design at our research center in western Montana with the aim of preliminarily determining whether certain cultivars may be prone to this phenomenon. Additionally, we evaluated two plant growth regulators (PGRs) to reduce PHFD in two cultivars previously observed to have high rates of PHFD. Results suggest cultivar-specific variations in PHFD near berry maturation. Because haskap harvest indices are not well-defined and may be cultivar-specific, we share our 1-year study results as preliminary information and as a call for further research. Cultivars Aurora, Boreal Blizzard, Borealis, Indigo Gem, Kapu, and Tana all had PHFD rates less than 12% of yield, where yield is the weight of berries lost to PHFD plus marketable yield and marketable yield is fruit remaining on the shrub at harvest. Cultivars Chito, Kawai, and Taka had the highest rates of PHFD, although marketable yields were still relatively high, especially for Kawai. We note that ease of fruit detachment is an important consideration in mechanical harvest, and this characteristic could be advantageous if managed appropriately. The PGRs evaluated (1-napthaleneacetic acid and aminoethoxyvinylglycine) did not influence PHFD rates; however, our study was limited by the sample size and by the lack of information regarding haskap abscission physiology. In summary, the haskap cultivars evaluated exhibited variable PHFD rates in the year of the study, and further research is needed to understand haskap fruit maturation, harvest indices, and abscission.
Postharvest Treatment Effects on ‘Somerset Seedless’ Cold-Hardy Table Grapes
(Informa UK Limited, 2024-05) Wang, Zhuoyu; Svyantek, Andrej; Miller, Zachariah; Jarrett, Bridgid; Green, Stacy; Kapus, Ashely
Limited amount of information is available for cold-hardy table grape postharvest storage and strategies to extend the storage time. ‘Somerset Seedless’ is a cold-hardy table grape with a potential market for the Upper Midwest and Northern Great Plains. Postharvest treatments were assessed as a possible route to increase cold-hardy table grape shelf-life. In this study, a 1.4% chitosan postharvest treatment was tested on ‘Somerset Seedless’ grapes through 7 weeks of storage with temperature 1–4°C, humidity ≥90%. The effects were compared to two controls: one was diH2O, and the other one was acetic acid. The assessment included grape appearance traits (rachis, decay, mold, scattering, and splitting), physiochemical properties (TSS, pH and total acidity), antioxidant activity, as well as total phenolics and flavonoid content. In general, 1.4% chitosan, 1% acetic acid, and diH2O had a large impact on grape appearance during storage with limited impact on chemistry. Throughout 7 weeks of storage, no significant differences were observed in grape physiochemical and phytochemical changes. Chitosan performed the best for ‘Somerset Seedless’ postharvest storage in regard to the low rate of visible damage. Although acetic acid had similarly positive effects on mold control as chitosan treatment, it caused the highest split rate after 1 week and the highest shatter rate after 5 weeks of storage. Chitosan treated ‘Somerset Seedless’ still met the USDA standard of table grapes after 5 weeks. This study suggests chitosan postharvest treatments may have applications for enhancing the shelf-life of cold-hardy table grapes.
Postharvest Treatment Effects on ‘Somerset Seedless’ Cold-Hardy Table Grapes
(Informa UK Limited, 2023-12) Wang, Zhuoyu; Svyantek, Andrej; Miller, Zachariah; Jarrett, Bridgid; Green, Stacy; Kapus, Ashley
Limited amount of information is available for cold-hardy table grape postharvest storage and strategies to extend the storage time. ‘Somerset Seedless’ is a cold-hardy table grape with a potential market for the Upper Midwest and Northern Great Plains. Postharvest treatments were assessed as a possible route to increase cold-hardy table grape shelf-life. In this study, a 1.4% chitosan postharvest treatment was tested on ‘Somerset Seedless’ grapes through 7 weeks of storage with temperature 1–4°C, humidity ≥90%. The effects were compared to two controls: one was diH2O, and the other one was acetic acid. The assessment included grape appearance traits (rachis, decay, mold, scattering, and splitting), physiochemical properties (TSS, pH and total acidity), antioxidant activity, as well as total phenolics and flavonoid content. In general, 1.4% chitosan, 1% acetic acid, and diH2O had a large impact on grape appearance during storage with limited impact on chemistry. Throughout 7 weeks of storage, no significant differences were observed in grape physiochemical and phytochemical changes. Chitosan performed the best for ‘Somerset Seedless’ postharvest storage in regard to the low rate of visible damage. Although acetic acid had similarly positive effects on mold control as chitosan treatment, it caused the highest split rate after 1 week and the highest shatter rate after 5 weeks of storage. Chitosan treated ‘Somerset Seedless’ still met the USDA standard of table grapes after 5 weeks. This study suggests chitosan postharvest treatments may have applications for enhancing the shelf-life of cold-hardy table grapes.