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  • Author or Editor: Joseph G. Masabni x
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Experiments were conducted in the last 3 years to evaluate the safety and efficacy of halosulfuron (Sandea 75WG) application under the plastic mulch within 7 days of transplanting tomato. In 2003, tomato plants were transplanted daily from day 0 through 7 after halosulfuron 0.051 kg a.i./ha application. Plant survival and height were collected. Tomato plants survived all dates of transplanting treatments. Plant height indicated that plants transplanted early were taller than those transplanted late, only because they had more time to establish and grow in the field. In 2004, tomatoes were set on a 2-day interval from day 0 through 10 after halosulfuron application. Halosulfuron 0.025 or 0.052 kg a.i./ha had no effect on plant height or yield. In 2005, an experiment was initiated to determine whether addition of trifluralin to halosulfuron under the plastic mulch will improve grass control and remain safe to tomatoes. Halosulfuron at 0.025, 0.052, and 0.1 kg a.i./ha, was applied alone and combined with trifluralin 0.63 kg a.i./ha. All treatments were applied under the plastic mulch. Tomato plants were transplanted at 6 days after application (DBT) and 0 DBT. Halosulfuron 0.1 kg ai/ha resulted in slight stunting and yield reduction of tomato, whether applied at 6 or 0DBT. However, this stunting was not statistically significant. Trifluralin didn't affect tomato yield at 6DBT and significantly increased yields at 0DBT for 0.052 and 0.1 ka a.i./ha halosulfuron rates. Trifluralin reduced grass biomass but resulted in an increase of nightshade biomass. Halosulfuron was determined to be very safe on tomato growth and yield, even if tomato was transplanted on the same day of application. Trifluralin also was found to have little or no effect on tomato growth or yield, and appears to have a potential use as an herbicide for under plastic application in tomato production.

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Halosulfuron (Sandea 75WG) is labeled for pre- or posttransplant use in tomato, cucumber, cantaloupe, among other vegetable crops. For pretransplant usage, the label specifies a 7-day waiting period after halosulfuron application under the plastic mulch before transplanting tomatoes. This period may be too long for growers who are busy in the spring with planting and pesticide sprays while on a race with the constantly changing climate of early spring. Experiments were conducted in the last 2 years to determine whether transplanting tomato within 7 days of halosulfuron application had any deleterious effects on tomato. In 2003, tomatoes were transplanted daily from day 0 through 7. Plant survival and height were collected. Tomato plants survived all dates of transplanting treatments. Plant height indicated that plants transplanted early were taller than those transplanted late, only because they had more time to establish and grow in the field. There was no adverse effect to tomato growth. In 2004, tomatoes were set on a 2-day interval from day 0 through 10 after halosulfuron application under the plastic mulch. Plant height, visual rating, % early blight infection, and yields were collected. A severe early blight infection confounded the results of herbicide applications. Still, it was clear that halosulfuron 0.026 or 0.051 kg a.i./ha had no effect on plant height or visual rating. Yields were not statistically different from those of the control, when the effect of early blight was factored out.

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Flumioxazin (Chateau 51WG) is an herbicide for the preemergence and early postemergence control of broadleaves and grasses. Chateau was recently labeled for use in non-bearing fruit trees and bearing grapes. Long-term weed control in apple, peach, and blueberry was investigated following fall application of herbicides. Treatments consisted of simazine 2.8 kg a.i., norflurazon 2.24 kg a.i., napropamide 2.24 kg a.i., and oryzalin 2.24 kg a.i. were applied on 11 Nov. 2003. Flumioxazin was also applied at 0.1 and 0.43 kg ai on apple and peach. All treatments included glyphosate 1 lb a.i. for burndown control of preexisting weeds. Weed control evaluation in mid-April or 4 months after application showed that flumioxazin-treated plots had no weeds present and no weed regrowth. Plots treated with napropamide, norflurazon, and oryzalin showed significant regrowth of dandelion, common ragweed, and chickweed. Simazine plots had fewer weeds germinating than the other herbicides. By early June or 6 months after application, no differences in residual weed control were observed for all treated plots when compared to the control. All plots were equally weedy and required immediate floor management measures. It appears that flumioxazin weed control benefit was exhausted by 6 months after application, compared to 4 months for all other herbicides. Fall application of flumioxazin can eliminate the need for early spring weed control. This time saved can be spent on other important activities such as pruning and disease and insect control.

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Three onion (Allium cepa L.) cultivar transplants were grown in the greenhouse in 200-cell plastic trays with one, two, or three plants per cell; at 75, 150, or 225 ppm N; and for 8, 10, or 12 weeks. Increasing the number of plants per cell resulted in smaller seedlings at transplanting and reduced time to maturity in the field by 1 week. Two and three plants per cell yielded more bulbs ≥76 mm in diameter, but one plant per cell had the highest percentage of bulbs ≥102 mm in diameter. Older seedlings and higher N applications produced larger plants at transplant and larger bulbs at harvest. Increasing N applications reduced maturation time slightly. Bulb fresh weight at harvest and yield of bulbs ≥76 mm in diameter were highest with 10- and 12-week-old transplants, and at 150 and 225 ppm N.

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A greenhouse experiment was conducted to determine the relative salt tolerance of pomegranate (Punica granatum) cultivars. Twenty-two pomegranate cultivars were irrigated weekly with a saline solution at an electrical conductivity (EC) of 10.0 dS·m–1 for 4 weeks and subsequently with a saline solution at an EC of 15.0 dS·m–1 for another 3 weeks (salt treatment). Another group of uniform plants was watered with a nutrient solution without additional salts at an EC of 1.2 dS·m–1 (control). No visual foliar salt damage (leaf burn, necrosis, or discoloration) was observed during the entire experimental period; however, salt treatment impacted pomegranate growth negatively, with a large variation among cultivars. Salt treatment reduced shoot length by 25% and dry weight (DW) by 32% on average for all cultivars. Cluster analysis classified the 22 tested pomegranate cultivars in two groups. The group consisting of ‘Arturo Ivey’, ‘DeAnda’, ‘Kazake’, ‘Russian 8’, ‘Apseronski’, ‘Purple Heart’, ‘Carolina Vernum’, ‘Chiva’, ‘Kunduzski’, ‘Larry Ceballos 1’, ‘ML’, ‘Salavatski’, ‘Spanish Sweet’, and ‘Wonderful’ was more salt tolerant than the group including ‘Al-Sirin-Nar’, ‘Kandahar’, ‘Surh-Anor’, ‘Early Wonderful’, ‘Angel Red’, ‘Ben Ivey’, ‘Utah Sweet’, and ‘Mollar’. The sodium (Na) concentration in the leaf tissue of all 22 pomegranate cultivars was less than 1 mg·g–1 on a DW basis. All pomegranate cultivars in the salt treatment had an average leaf chloride (Cl) content of 10.03 mg·g–1 DW—an increase of 17% from the control. These results indicate that pomegranate plants have a strong capability to exclude Na and Cl accumulation in leaf tissue. In conclusion, the pomegranate plant is very tolerant to saline water irrigation up to an EC of 15 dS·m–1 with little foliar salt damage and a slight growth reduction. Investigation is needed to determine the effects of saline water on the fruit yield and nutritional quality of pomegranate.

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Consumption of basil (Ocimum basilicum) has been increasing worldwide in recent years because of its unique aromatic flavor and relatively high concentration of phenolics. To achieve a stable and reliable supply of basil, more growers are turning to indoor controlled-environment production with artificial lighting due to its high environmental controllability and sustainability. However, electricity cost for lighting is a major limiting factor to the commercial application of indoor vertical farming, and little information is available on the minimum light requirement to produce uniform and high-quality sweet basil. To determine the optimal daily light integral (DLI) for sweet basil production in indoor vertical farming, this study investigated the effects of five DLIs, namely, 9.3, 11.5, 12.9, 16.5, and 17.8 mol·m−2·d−1 on basil growth and quality. ‘Improved Genovese Compact’ sweet basil was treated with five DLIs provided by white fluorescent lamps (FLs) for 21 d after germination, and gas exchange rate, growth, yield, and nutritional quality of basil plants were measured to evaluate the effects of the different DLIs on basil growth and quality. Results indicated that basil plants grown under higher DLIs of 12.9, 16.5, or 17.8 mol·m−2·d−1 had higher net photosynthesis, transpiration, and stomatal conductance (g S), compared with those under lower DLIs of 9.3 and 11.5 mol·m−2·d−1. High DLIs resulted in lower chlorophyll (Chl) a+b concentration per leaf fresh weight (FW), higher Chl a/b ratios, and larger and thicker leaves of basil plants. The shoot FW under DLIs of 12.9, 16.5, and 17.8 mol·m−2·d−1 was 54.2%, 78.6%, and 77.9%, respectively, higher than that at a DLI of 9.3 mol·m−2·d−1. In addition, higher DLIs led to higher soluble sugar percent and dry matter percent than lower DLIs. The amounts of total anthocyanin, phenolics, and flavonoids per plant of sweet basil were also positively correlated to DLIs, and antioxidant capacity at a DLI of 17.8 mol·m−2·d−1 was 73% higher than that at a DLI of 9.3 mol·m−2·d−1. Combining the results of growth, yield, and nutritional quality of sweet basil, we suggest a DLI of 12.9 mol·m−2·d−1 for sweet basil commercial production in indoor vertical farming to minimize the energy cost while maintaining a high yield and nutritional quality.

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Canopy architecture, yield components, berry composition, pruning weight, Ravaz Index, and midwinter primary bud cold hardiness of own-rooted ‘Vidal blanc’ (Vitis vinifera × Vitis rupestris) were measured in response to balanced pruning formula treatments of 20, 30, or 40 nodes retained for the first 454 g of dormant pruning weight and an additional 10 nodes for each additional 454 g and three cluster thinning levels of one, two, and two+ clusters per shoot in 2006 and 2007. Although the pruning formula affected the distance between shoots along the canopy, and the number of count shoots per hectare, the canopy leaf layer numbers were unaffected in either year. Application of the pruning formula did not affect components of yield in either year. However, the number of clusters and yield per vine were affected by cluster thinning treatments where they increased linearly with the decrease in its severity, explaining 73% and 77% of total variance in yield in 2006 and 2007, respectively. Pruning formula or cluster thinning did not affect berry composition substantially. Cluster thinning improved the percentage of mature nodes on shoots before a killing frost in both years. Cluster thinning to one or two clusters per shoot also improved the lethal temperature killing 50% of the primary buds compared with no cluster thinning in both years of the study. Mature wood weight and total pruning weight displayed a quadratic response to cluster thinning where two clusters per shoot had the greatest weight for both, whereas pruning formula had no effect on pruning weight. Optimum fruit weight–pruning weight ratio was achieved with the 30 + 10 pruning formula and two clusters per shoot cluster thinning treatments in both years of the study. The results of this study provide valuable information for growers of interspecific hybrids such as ‘Vidal blanc’ in the lower midwestern United States as well as in other regions with long, warm growing seasons. Balanced pruning to 30 nodes per 454 g of dormant prunings and cluster thinning to two clusters per shoots optimized yield, maintained fruit composition, improved primary bud cold hardiness, and achieved an optimum fruit weight-to-pruning weight ratio of 10.0 kg·kg–1. Thus, this approach should be used for ’Vidal blanc’ in the lower midwestern United States to sustain production.

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The pawpaw [Asimina triloba (L.) Dunal] has great potential as a new fruit crop. A pawpaw variety trial was established in Fall 1995 in Princeton, Ky. as a joint Kentucky State Univ.-Univ. of Kentucky research effort with the objective to identify superior varieties for Kentucky. A randomized block experimental design was used with 8 replicates of 28 grafted scion selections on seedling rootstock. Cultivars being tested included Middletown, Mitchell, NC-1, Overleese, PA-Golden, Rappahannock, Shenandoah, Sunflower, Susquehanna, Taylor, Tay-two, Wells, and Wilson. The other 15 clones were selections from the PawPaw Foundation. In 2002 and 2003, the following parameters were examined: tree survival, trunk cross-sectional area (TCSA), average fruit weight, total fruit harvested per tree, average fruit per cluster, total yield per tree, and yield efficiency. In 2003, 54% of the trees had survived, with `Susquehanna' (13%) showing the poorest survival. Based on TCSA, most selections displayed excellent vigor, with the exception of the selections: 5-5 and `Overleese'. Average fruit weight was greatest in 1-7-2 (194 g), 1-68 (167g), 4-2 (321 g), 5-5 (225 g), 7-90 (166g), 9-58 (176 g), 10-35 (167 g), NC-1 (180 g), `Sunflower' (204 g), and `Shenandoah' (168g), with the smallest fruit in `Middletown' (70 g), `Wells' (78 g), and `Wilson' (88 g). The selections `Wilson' (81), `Middletown' (75), and `Wells' (70) had the greatest average number of fruit per tree, whereas 4-2 (9), 5-5 (17) and 8-20 (15) the fewest. Yield efficiency and average fruit per cluster also varied greatly among selections. Several pawpaw selections in the trial show promise for production in Kentucky.

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