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Previous work has shown that container grown landscape plants use, and likely need, much less water than is typically applied. Therefore, studies were conducted to quantify the relationships between water loss and water stress responses using several drought tolerant (Cassia corymbosa, Leucophyllum frutescens, Salvia greggii) and traditional landscape plants (Euonymus japonicus, Pyracantha coccinea). Water stress was induced by withholding water and water loss measured gravimetrically. The shape of the water loss curve was similar for all species being, Y = a + bx + cx2 (r2 > 0.95). The rate of ethylene production began to increase 24 hr after irrigation, reaching a maximum 36-48 hr after irrigation and then decreasing. Maximum ethylene production occured at 35-47% water loss irrespective of species or rate of water loss. Stress symptoms (wilting leaf discoloration and abscission) followed a similar pattern. The potential for monitoring gravimetric water loss to schedule container irrigation will be discussed.

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Previous work has shown that container grown landscape plants use, and likely need, much less water than is typically applied. Therefore, studies were conducted to quantify the relationships between water loss and water stress responses using several drought tolerant (Cassia corymbosa, Leucophyllum frutescens, Salvia greggii) and traditional landscape plants (Euonymus japonicus, Pyracantha coccinea). Water stress was induced by withholding water and water loss measured gravimetrically. The shape of the water loss curve was similar for all species being, Y = a + bx + cx2 (r2 > 0.95). The rate of ethylene production began to increase 24 hr after irrigation, reaching a maximum 36-48 hr after irrigation and then decreasing. Maximum ethylene production occured at 35-47% water loss irrespective of species or rate of water loss. Stress symptoms (wilting leaf discoloration and abscission) followed a similar pattern. The potential for monitoring gravimetric water loss to schedule container irrigation will be discussed.

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The US landscape industry consists of 632,000 businesses with >1 million persons employed in 2022. The most common service that landscape service providers (LSPs) perform is pest management. Over the past 25 years, LSPs have been challenged to adopt more holistic approaches to pest management via the use of nonchemical and less toxic chemical controls. Integrated pest management (IPM), specifically scouting, may be a useful approach for LSPs to manage pests more sustainably and market new services, such as biological control releases. Scant literature is available on LSP scouting practices or consumer acceptance of scouting services. The goal of this study was to determine if IPM-aware consumers were more likely to purchase a scouting program offered by an LSP. An online survey was distributed across the United States through a third-party panel service. The final sample included 928 usable responses. Data were analyzed using a binary logistic regression model. Fifty-seven percent of respondents reported having some knowledge or were very knowledgeable of IPM. Respondents 65 years of age and older were 13.1% points less likely to purchase a scouting service. Education level did not influence purchase likelihood. Consumer knowledge of IPM had a positive influence on the purchase likelihood, respondents with “some knowledge” (5.6%) and “very knowledgeable” (8.6%) were more likely to buy IPM services. Further, if the consumer was open to purchasing the scouting program, it is plausible that they might be more willing to allow an LSP to use a combination of chemical and nonchemical methods to manage pests.

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ReTain™ is a plant bioregulator containing the active ingredient aminoethoxyvinylglycine (AVG), which inhibits the ethylene biosynthesis pathway. In 1997, the first efficacy studies on `Royal Gala' apple with ReTain™ were conducted under New Zealand conditions in Hawkes Bay. ReTain™ was applied 4 weeks before the anticipated start of harvest on `Royal Gala' at 850 and 1700 g·ha–1 with or without adjuvants. ReTain™ application delayed the onset of `Royal Gala' fruit maturation between 1 and 2 weeks, resulting in enhanced fruit size and fruit flesh firmness at harvest. The optimum response for delaying the onset of fruit maturation was achieved using ReTain™ at 850 g·ha–1 if applied in combination with a wetter. Fruit were also graded for fruit quality and air-stored at 0.5 °C. Fruit after 10 weeks of storage showed no difference in fruit flesh firmness, but all ReTain™ treatments had fruit with less yellow background colour compared with untreated fruit. In 1998, efficacy studies were undertaken in three geographical locations on `Royal Gala'. ReTain™ was applied at a rate of 830 g·ha–1 in combination with Silwet L-77 at 0.1%. All trees with the exception of `Royal Gala' grown in the Hawkes Bay had not received any ReTain™ previously. In all regions, seasonal changes in background color and starch pattern index were delayed by ReTain™ treatment. A concurrent delay of an increase in soluble solids concentration and retention of higher flesh firmness were also induced by ReTain™ treatment.

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During the past several years, watermelon trials have been performed in the state, but not as a coordinated effort. Extensive planning in 1997 led to the establishment of a statewide watermelon trial during the 1998 growing season. The trial was performed in five major production areas of the state including: The Winter Garden (Carrizo Springs); South Plains (Lubbock); East Texas (Overton); Cross Timbers (Stephenville); and the Lower Rio Grande Valley (Weslaco). Twenty seedless and 25 seeded hybrids were evaluated at each location. Drip irrigation with black plastic mulch on free-standing soil beds was used to grow entries in each area trial and yield data was recorded in a similar manner for each site. Results were reported in a statewide extension newsletter. Future plans include a continuation of the trial in the hope that multiple-year data will provide a basis for valid variety recommendations for watermelon producers in all areas of the state.

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Potato (Solanum tuberosum) is an important agricultural crop for Florida. From 1996 to 2000, the winter and spring potato crop was grown on an average of 15,782.7 ha (39,000 acres) and valued at $117 million. Variety evaluation and selection is an important tool to improve production efficiency and increase the competitiveness of Florida growers. A red-skinned potato variety evaluation was conducted in northeastern Florida in 2002. The experimental design was a 4 (site) × 5 (variety) factorial with four replications at each site. The four sites were the University of Florida's Plant Science Research and Extension Unit and three local commercial farms. Potato varieties in the trial were `Red LaSoda', `LaRouge', B0984-1, B1145-2, and B1758-3. Marketable tuber yields were 36.3, 35.6, 30.2, 20.3, and 21.4 t·ha-1 (324, 318, 269, 181, and 191 cwt/acre) respectively, with tuber yields of the two named varieties significantly higher than the numbered entries. Specific gravity ranged from 1.060 (`Red LaSoda') to 1.070 (B0984-1). There were no significant differences among entries for total cull weight or the incidence of hollow heart, brown rot, or corky ringspot. However, a higher percentage of B0984-1 tubers showed symptoms of internal heat necrosis than all other varieties. Potato varieties ranked from lowest to highest in overall appearance were `LaRouge', `Red LaSoda', B1758-3, B0984-1, and B1145-2. Higher appearance ratings in the numbered entries were attributed to darkerred skin color, rounder tuber shape, and shallower eyes compared to `Red LaSoda' and `LaRouge'. `Red LaSoda' and `LaRouge' will continue to be recommended as the standard redskinned potato varieties for Florida. However, B0984-1 and B1145-2 had desirable characteristics and should be planted in larger plantings to further evaluate quality and production characteristics.

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Potato (Solanum tuberosum) is a high value crop in Florida. It consistently ranks in the top five valued vegetable crops produced in the state. The identification of new potato varieties that improve production efficiency is an imperative because of constantly evolving market and production demands. A chip potato variety evaluation experiment was conducted in northeast Florida in 2002 to compare the production characteristics of industry standards to advanced selections. The potato varieties evaluated in this experiment were bred specifically for processing by the potato chip industry. The experimental design was a four (site) by five (variety) factorial with four replications at each site. The sites were the University of Florida's research farm in Hastings, FL and three commercial farms in the surrounding area. Potato varieties were two seed sources of `Atlantic', as well as, `Snowden', B0564-8, and B0766-3. Marketable yield for each variety was 39.4, 33.4, 38.4, 33.6, and 33.6 t·ha-1 (351, 298, 343, 300, and 300 cwt/acre), respectively. Total yield of B0564-8 was statistically equivalent to an `Atlantic' standard at all four locations and similar to `Snowden' at three of four locations. Specific gravity of B0564-8 and B0766-3 was significantly lower than that of `Atlantic' from both sources but within acceptable range for chip potatoes. B0564-8 tubers had the highest overall appearance ratings and the most consistent size and shape. B0564-8 and B0766-3 tubers had a significantly lower percentage of hollow heart and internal heat necrosis than `Atlantic' tubers. This resulted in overall better chip ratings for the numbered entries compared to `Atlantic' tubers. A potential fit for B0564-8 and B0766-3 in northeastern Florida production may be as a late season chip variety when the potential for the development of internal heat necrosis increases.

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Papaya seedlings segregate for sex expression as females or hermaphrodites. Typically only hermaphrodite fruit are marketed in Hawaii. The agronomic practice of growing multiple seedlings that are later thinned to a single hermaphrodite tree is wasteful of seed, labor, and resources, especially when seed is costly. We compared growth of plants propagated by the clonal methods of micropropagation or rooting vegetative cuttings versus plants initiated as seedlings and transplanted. The seedlings were either single-planted hermaphrodites as identified by the polymerase chain reaction (PCR) or multiple-planted, thinned seedlings. The experiments were carried out in three different locations on two islands in Hawaii. Clonally propagated plants were significantly shorter than seedlings and bore flowers earlier and lower on the trunk at all locations. Stem diameter differences were not significant even though plant size was different at planting time. Percentage of trees in bud varied significantly in the third month after transplanting when about 90% of the rooted cuttings and large micropropagated plants had formed flower buds while only one multiple-planted seedling developed a bud. Overall, the clonally propagated plants were more vigorous and earlier bearing than were the seedling plants. There is good potential for adoption of clonal propagation when production becomes efficient enough to compete in price with the current practice of over planting and thinning.

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Gynodioecious papaya (Carica papaya L.) seedlings in commercial cropping systems in Hawaii are typically multiple-planted and thinned upon flowering to a single hermaphrodite because seedlings segregate for sex expression. Use of clonally propagated hermaphrodites would eliminate the over-planting practice and may provide other advantages. Yields of clonally propagated hermaphrodites were compared with single- and multiple-planted seedlings in three fields on two islands in Hawaii. Cloned hermaphrodites were either rooted cuttings or in vitro micropropagated plants. Clonally propagated plants bore ripe fruit 1 to 3 months earlier than thinned seedlings and had significantly higher early and cumulative yields. At each site, cumulative yields of thinned seedlings never reached the same level as those of clonally propagated plants. The yield benefit from clonally propagated plants was greatest at Keaau, the lowest sunlight and least productive test site.

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