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The future of agricultural water availability is threatened by climate change, population growth, and environmental regulations. Most of the global water is being used for crop irrigation. The objective of this research was to determine optimum timer-based controller settings and controlled-released fertilizer rates for ‘American Red’ (Pelargoium ×hortorum) potted geranium plants. Fertilizer was top-dressed at 3, 6, or 9 g. Plants were irrigated by a timer-based controller set to water at 11:00 AM every other day for 2 minutes, 9:00 AM and 2:00 PM for 1 minute per day, 11:00 AM for 1 minute per day, 11:00 AM for 2 minutes per day, and a control of manual hand watering. Data regarding plant growth, soil and leaf nutrients, and water use were collected. For geranium growth factors, the total flowers per plant was greatest for irrigation at 11:00 AM for 1 minute with 6 g fertilizer. Plant height and shoot dry weight were greatest for 6 and 9 g fertilizer. The number of umbels and soil plant analysis development (SPAD) chlorophyll meter readings were greatest for 9 g fertilizer. For geranium soil nutrient content, the pH was greatest for 3 g fertilizer, whereas the electrical conductivity, potassium, nitrate, sulfate, and boron were greatest for 6 and 9 g fertilizer. Regarding the nutrient content of the leaves, total nitrogen, boron, iron, and copper were greatest for 9 g fertilizer. Water use efficiency was greatest with 6 and 9 g fertilizer and irrigation 1 minute per day at 11:00 AM. The findings indicated that using timer-based controlled irrigation systems programmed to water for 1 minute during the morning with 6 g fertilizer resulted in plants that not only reduced water consumption but also enhanced water use efficiency and overall plant quality.
Pawpaw (Asimina triloba) is a fruit-bearing tree native to North America, and nurseries have a strong public demand for grafted trees. Most nurseries currently propagate pawpaw cultivars clonally through chip budding and whip-and-tongue grafting, both onto pawpaw seedling rootstock. Flexibility in successful grafting and budding techniques can optimize the type and quality of available scionwood while using the available labor. In an initial experiment, a range of pawpaw selections were subjected to grafting and budding techniques that indicated candidate cultivars and advanced selections for further examination. Therefore, the objective of this study was to determine the optimal method of propagating the pawpaw cultivars, KSU-Atwood™, KSU-Chappell™, and the advanced selection Hi7-1 using chip budding, whip and tongue, T-budding, and a cleft grafting tool. Additional trees, each of KSU-Atwood™ and KSU-Chappell™, were also subjected to green budding in the summer with the current season’s scionwood. Whip and tongue grafting was the most successful method, with a scion survival rate (SSR) of 95.8%, followed by the cleft grafting tool (SSR = 66.7%) and chip budding (SSR = 50.0%), then T-bud grafting (SSR = 25.0%), and lastly green bud grafting (SSR = 0.0%). There were no cultivar differences for the grafting techniques used. The whip-and-tongue method had the highest scion survival rate; however, cleft grafting and chip budding can be effective propagation methods for nurseries if scionwood quality does not support the whip-and-tongue grafting technique. In addition to whip-and-tongue grafting, the cleft grafting tool is a viable option for grafting pawpaw for use by personnel with less grafting experience or skill.
‘Marquette’ is a cold-hardy hybrid grape cultivar that has received increased attention for its use in wine production in the upper midwestern and northeastern United States since it was released in 2006. However, ‘Marquette’ is an early budburst cultivar susceptible to spring freeze damage. We examined the influence of high wire bilateral flat cane (HWC) and four-arm Kniffin (4AK) training systems on young ‘Marquette’ performance during a year with spring freeze damage (2017) and the subsequent season without frost events (2018). In 2017, there were two consecutive spring frost events at the experimental site approximately 2 weeks after the vines reached 50% budburst, which damaged more than 70% of the shoots. The percentage of freeze-damaged shoots and the severity of freeze damage to green tissues did not differ between training systems, but 4AK vines had higher yield at harvest (5.16 kg/vine or 3.12 tons/acre) than HWC vines (3.45 kg/vine or 2.10 tons/acre) because of the greater number of buds retained at winter pruning. There was no freeze damage close to budburst in 2018, and the yield of 4AK vines was still higher (11.74 kg/vine or 7.08 tons/acre) than that of HWC vines (8.20 kg/vine or 4.98 tons/acre). In 2018, the Ravaz index (yield-to-pruning weight) values were lower for HWC vines (3.41) than for 4AK vines (5.39), but the training system did not consistently affect fruit composition in either vintage. Within the 4AK system, shoots that emerged from the lower cane had more freeze damage than those of the upper cane and produced lower crop yield and fruit with lower soluble sugars in both vintages. Our results suggest that ‘Marquette’ vines can be grown on a training system with high cropping potential, such as a divided canopy system or a single canopy, with a higher number of buds and shoots than that of our study. Among divided canopy systems, 4AK might not be the best option for vigorous ‘Marquette’ vines because, in addition to greater susceptibility to freeze damage, the lower cane of 4AK was highly shaded by the upper highly vegetative canopy, which might have caused its lower productivity and soluble sugars at harvest compared with those of the upper cane.
Fresh eucalyptus stems can be preserved via systemic absorption of glycerin, but the optimal rate of glycerin and its effect on foliage color and stem pliability during holding have not been well-described. We harvested stems of Eucalyptus pulverulenta ‘Baby Blue’ and treated them in solutions of 0% (control), 25%, 50%, and 75% glycerin:reverse-osmosis water for 2 weeks. Leaf greenness was measured nine times during this period; the change in stem weights and solution uptake were measured as well. Stem pliability was evaluated after 2 weeks in solution as well as 1 week after holding the stems dry. The 25% and 50% glycerin treatments increased stem weight, whereas the control and 75% treatments decreased stem weight. The glycerin treatments absorbed less than 50 mL solution per three stems during 2 weeks, whereas those in the control absorbed >270 mL water. The color of foliage was similar during the first 5 days in treatment solutions, but stems in 25% and 50% glycerin treatments were less green than those in the control and 75% treatments by day 6, and this trend continued. No difference occurred in stem pliability among treatments after 2 weeks in glycerin solutions; however, after 1 week of holding, the top 9 cm of stems in glycerin treatments were more pliable than those in the control. Based on these results, we recommend a rate of 25% glycerin to preserve eucalyptus foliage for use in botanical artistry.
Fresh market vegetables are an essential component of the human diet. Maximizing yield is critical, and to achieve this goal, fields must be weed-free when vegetable crops are planted. Historically, removing emerged weeds just before planting has been accomplished using the herbicide glyphosate. However, recent research has indicated that glyphosate applied to sandy, low-organic-matter soils just before transplanting vegetables can be injurious. Two field experiments investigated 1) the response of transplanted squash to the residual activity of glyphosate, and 2) the effects of implementing tillage, irrigation, or extending the plant-back interval after application and before planting to mitigate injury from glyphosate. Glyphosate applied at 1.3, 2.5, or 3.8 kg ae/ha 1 day before transplanting injured squash 13%, 29%, and 53%, respectively; extending the interval between application and planting to 7 days reduced injury to 1%, 11%, and 28% at the same rates. An interaction between application rate and planting interval was also observed on squash plant widths and biomass, as well as early-season and total marketable fruit numbers and weights. Total marketable fruit number was reduced 29% and 52% by glyphosate at 2.5 or 3.8 kg ae/ha, respectively, and a reduction in fruit production of 36%, 28%, and 23% was observed when glyphosate was applied 1, 4, or 7 days before transplanting, respectively. In a separate study, light tillage (5 cm deep) was the most effective cultural practice evaluated because it eliminated damage by glyphosate. Overhead irrigation of 0.6 cm was not beneficial in mitigating injury by glyphosate. Recommendations from this research will help vegetable growers avoid injury from the residual activity of glyphosate through a FIFRA 2(ee) recommendation label.
It has been documented that sweetpotato (Ipomoea batatas L.) cultivars vary in morphological and physiological adaptations to low phosphorus (P) availability but knowledge of the underlying molecular mechanisms is largely unknown. The objective of this research was to generate cultivar-specific information about phosphate starvation response (PSR) genes to variations in inorganic phosphate (Pi) availability at the onset of storage root formation among sweetpotato cultivars. Cultivars Bayou Belle (BB), Evangeline (EV), and Orleans (OR) were grown under varying Pi levels: 0 mg·L−1 (low Pi), 15 mg·L−1 (Pi-sufficient), and 31 mg·L−1 (high Pi). Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) analysis of PSR genes IbPHR1, IbSPX1, IbSPX3, IbPHT1;4, IbPHT1;5, and IbNLA was performed at 5 and 10 days after planting (DAP), corresponding to adventitious root system establishment and the onset of storage root formation, respectively. The cultivar BB grown under low Pi showed significantly higher expression of all genes except IbPHR1. The cultivar OR grown in both low and high Pi exhibited upregulation of IbPHR1. On the other hand, EV grown under low Pi revealed no response for all genes investigated. Exposure of BB to high Pi resulted in a decrease in expression for all genes except IbNLA. The cultivar EV grown in high Pi conditions showed increase in expression for IbSPX1, IbPHT1;5, and IbNLA. Expression pattern difference among cultivars relative to Pi levels corroborates field observations showing that BB, EV, and OR have different Pi requirements. The increased activity of BB PSR genes grown under low Pi supports the hypothesis that BB requires low P fertilizer input relative to OR and EV. Results from this study corroborate findings from well-characterized crop species and model systems and pave the way for the development of tools and practices to increase phosphorus use efficiency in sweetpotato.
Open-field-grown tomatoes in Saudi Arabia are stressed by poor soil fertility because of the low organic matter content, low nutrient availability, and high pH. Thus, high chemical fertilizer inputs are crucial for commercial production; however, they cause economic loss as well as negatively affect environmental sustainability. The use of efficient organic fertilizers would be useful for developing more cost-effective, environmentally friendly, and sustainable agriculture. The current study evaluated the impact of Black soldier fly (Hermetia illucens L.) frass (BSFF) fertilizer applications as organic fertilizer on postharvest fruit quality and shelf life of open-field-grown F1 hybrid ‘Sinag Tala’ tomatoes compared with those grown under control treatment (received recommended doses of chemical fertilizers for tomato production under open field conditions). The experiment was conducted using a randomized complete block design with four replicates. The results showed that the application of BSFF fertilizer, especially at the higher rate (5 ton/ha; BSFF3), improved the overall quality of tomato fruit. The BSFF fertilizer treatments reduced weight loss, maintained higher firmness, antioxidants [vitamin C, total phenol content (TPC) and total flavinoid (TFC)], total soluble solids (TSS), and titratable acidity (TA) contents, and lowered the TSS/TA ratio of fruits during shelf life compared with those of the control. The decay incidence was only detected after 9 days of shelf life and was significantly lower in all the BSFF fertilizer treatments (range, 8.40%-12.05%) than in the control (15.9%). In addition, BSFF fertilizer treatments reduced both disease incidence and severity of gray mold following pathogen inoculation during shelf life compared with those of the control. These results might be attributable to the higher antioxidants content (vitamin C, TPC, and TFC) and higher polyphenol oxidase activity in BSFF-fertilized tomatoes. In conclusion, BSFF fertilizer could be used as a potential eco-friendly alternative to chemical fertilizers to improve tomato fruit quality during shelf life.