In the midwestern United States, especially Missouri, winegrape (Vitis sp.) growers mostly plant interspecific hybrids, which are well adapted to the climate and pests of the region. ‘Chambourcin’ (an interspecific French-American hybrid) is one of the most widely planted winegrape cultivars in the area. It is usually grown as own-rooted (nongrafted) vines because the economic and horticultural benefits of grafting this cultivar to rootstocks have not been well developed. Further, few significant winegrape rootstock evaluations have been conducted in the midwestern United States, including evaluations of newer rootstocks developed and released by private and public breeding programs. The aim of this study was to assess the potential value of using rootstocks in ‘Chambourcin’ production in southern Missouri, with implications for the midwestern United States. Fruit yield, vine growth, and fruit composition metrics from ‘Chambourcin’ on 10 different root systems [own-rooted, and grafted to rootstocks ‘Couderc 3309’, ‘Couderc 1616’, ‘Paulsen 1103’, ‘Sélection Oppenheim 4’, ‘Millardet et de Grasset 420A’, ‘Millardet et de Grasset 101-14’, ‘Kingfisher’, ‘Matador’ (all Vitis sp.), and ‘Gloire de Montpellier’ riverbank grape (Vitis riparia)] in an experimental vineyard in southwest Missouri were compared. Following three establishment years (2008–10), data were collected across four growing and vintage seasons (2011–14). Yield components evaluated included total fruit production, clusters per vine, cluster weight, berry weight, weight of cane prunings, and crop load. Petiole mineral analysis was conducted in 2011, 2013, and 2014. Grape juice attributes measured were soluble solids concentration, juice pH, titratable acidity (TA), potassium (K), anthocyanins, tannins, phenolics, and organic acids. When simply comparing grafted vs. ungrafted vines, grafting generally induced higher plant vigor and a higher pH in the juice, whereas the other parameters did not differ. When the performances were compared among the 10 root systems, vines grafted to ‘Couderc 3309’ had higher yields compared with vines grafted to six other rootstocks and own-rooted vines. Grafting to ‘Millardet et de Grasset 101-14’ induced higher cluster weight compared with the other rootstocks. The ‘Millardet et de Grasset 420A’ rootstock promoted a higher pH and TA as well as a higher concentration of K in the juice, and ‘Paulsen 1103’ also promoted high pH, TA, and malic acid in the juice, and higher concentrations of phosphorous (P) and K in the petiole compared with most rootstocks. ‘Gloire de Montpellier’ induced a lower P content in the petiole and a higher tartaric/malic acid ratio. Rootstock use can strongly influence some vineyard production metrics as well as nutrient uptake and K levels in the juice (the latter further influencing juice pH). The results of this study provide insights into the complex viticultural and enological interactions resulting from the use of rootstocks in hybrid winegrape production in Missouri, USA.
We compared the performance of Brussels sprout (Brassica oleracea var. gemmifera) cultivars in New Hampshire and evaluated the effects of topping (apical meristem removal) on marketable yields. A total of 23 cultivars were evaluated in the study, with 8 to 16 cultivars evaluated in any given year. We identified several cultivars that produced moderate to high yields of well-spaced, uniform sprouts that had few Alternaria blight (Alternaria sp.) symptoms, and identified many others, including all red cultivars evaluated, that produced very low yields consistently. In 2013, 2014, and 2015, we used a replicated split-plot experimental design with cultivar as the main plot and topping treatment as the subplot, to evaluate the effects of topping plants. Early and midseason cultivars showed increased yields in response to topping, unless topping was performed too early. Cultivars with sprouts that did not reach marketable size within our growing season generally produced low yields, and topping had no effect on yields. To explore the effects of topping at different dates, we evaluated three cultivars on seven different topping dates plus an untopped control in 2015 and 2017. In addition to reducing stalk height by limiting late-season growth, topping affected marketable yields by affecting the number of sprouts that were either undersized or oversized. The ideal topping date window for minimizing defects and maximizing yields varied slightly for each cultivar, ranging from early to late September.
‘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.
Increasing labor and input costs have driven wine grape (Vitis vinifera) growers’ attention to mechanized equipment to assist in vineyard operations. This study evaluates the financial feasibility of investing in vineyard mechanization, in addition to the released intelligent sprayer in hypothetical wine grape vineyards of varying sizes. Our comparative analysis illustrates how mechanization of vineyard practices affects costs and financial metrics. We conducted a cost–benefit analysis for seven investment scenarios and examined the economic performance of four metrics. Our findings suggest that investing in a mechanized trimmer is most effective for growers exposed to labor shortages and high wages. A retrofitted intelligent sprayer is superior for reducing input use and associated costs.
Micropropagation of hemp (Cannabis sativa) is constrained by problems with hyperhydricity and culture decline of microshoots. These problems can be reduced by increasing agar and nutrients in the media during micropropagation stages 1 and 2, respectfully. Performance of microshoots of ‘Abacus’ and ‘Wife’ hemp cultured in Driver and Kuniyuki Walnut medium (DKW) for 15 weeks (6 weeks of stage 1 + 9 weeks of stage 2), with subculturing every 3 weeks during both stages 1 and 2, or in Murashige and Skoog with vitamins medium (MS) for 6 weeks (stage 1) followed by Lubell-Brand Cannabis medium (LBC) for 9 weeks (stage 2), with subculturing every 3 weeks during both stages 1 and 2, was evaluated. In a separate study, microshoot performance of ‘Abacus’ and ‘Wife’ in MS for 3 weeks (stage 1) followed by LBC for 6 weeks (stage 2), with subculturing every 3 weeks, using boxes (Magenta GA-7) with lids featuring a vent with a diameter of 10 mm and a pore size of 0.2 µM or using microboxes (Sac O2 O95/114 + OD95) with lids featuring a filter (Sac O2 #10) were evaluated. Shoot multiplication rate (SMR) and explant height were greater for ‘Abacus’ in LBC than DKW. For ‘Wife’, SMR at 9 weeks was greater in LBC, as LBC provided more nutrients and water than cultures had received in MS initially during stage 1. Culture medium did not influence ex vitro rooting success, which was 75% for ‘Abacus’ and ≥ 90% for ‘Wife’. Microboxes resulted in greater hyperhydricity of shoots and a lower ex vitro rooting percentage than boxes. For cultivars that are highly prone to developing hyperhydricity, like ‘Abacus’, the microboxes were not adequate to control this condition.
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.
This study examined the interaction between constant liquid fertilization (CLF) concentrations and plant growth regulator (PGR) application concentrations on petunia (Petunia ×hybrida) growth and flowering in the production and post-production environments. Paclobutrazol application is a common practice in bedding plant production to achieve a compact plant that increases greenhouse space-use efficiency, shipping density, and tolerance to physical handling stresses in the post-production environment. The objective of this research was to determine the best strategy for balancing CLF and PGR application concentration in the greenhouse environment so that growth and flowering can be maximized in the post-production environment. A two-factorial combination of four CLF concentrations [50, 100, 150, or 200 ppm nitrogen (N)] and four paclobutrazol drench concentrations (0, 5, 10, or 20 ppm) were provided to plants during the production phase, and plant growth and flowering were recorded in the production and post-production environments. From a sustainability perspective, the ideal PGR concentration was 5 ppm paclobutrazol, since this concentration resulted in the best combination of production and post-production characteristics and performance. At this PGR concentration, all plant growth and flowering measures increased as CLF increased from 50 to 200 ppm N; however, all CLF concentrations also produced commercially acceptable plants. Therefore, the ideal CLF concentration depends on the size of plant desired; that is, CLF concentrations as low as 50 to 100 ppm N can be provided depending on the market size requirements of the plants being grown. Based on our results, a combination of 50 ppm N CLF with 0 ppm paclobutrazol or 100 ppm N CLF with 5 ppm paclobutrazol both demonstrated adequate growth control during both production and post-production phases.
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.