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Maria P. Paz*, Jeff S. Kuehny, Gloria B. McClure, Richard Criley, and Charles J. Graham

Ornamental gingers are popular cut flowers and have been promoted as a promising potted flower crop because of unique foliage, long-lasting colorful bracts, and few pest problems. Rhizomes are the primary means of propagation in late spring followed by shoot growth and flowering, and plants enter dormancy under short days in the fall. Termination of dormancy is important for greenhouse forcing and extending the growing season. Manipulation of rhizome storage to satisfy dormancy requires investigation into the storage environment. It appears that controlling growth, development and flowering in geophytic plants is dependent on reserve accumulation, mobilization, and redistribution. Rhizomes of four ginger species (Curcuma alismatifolia Gagnep., C. roscoeana Wallich, Globba winittii C.H. Wright, and Kaempferia galanga L.) were stored for 0 to 16 weeks at 15, 20, or 25 °C to determine the effect on growth, flowering, respiration rates, and carbohydrate content. Upon completion of treatment application, rhizomes were planted in a peat moss:bark:perlite mix and placed in a greenhouse with 25 °C day/21 °C night temperatures with 40% shade. The production time, days to emergence (DTE) and days to flower (DTF), was reduced with an increase in storage temperature and duration for all species. DTE and DTF for Globba and Kaempferia were hastened when rhizomes were stored for 16 weeks at 25 °C. For C. alismatifolia, DTE and DTF were hastened when rhizomes were stored at 25 °C for at least 10 weeks. For C. roscoeana, storage at 25 °C for 14 or 16 weeks was found to hasten emergence. The response of respiration and carbohydrate concentration was not consistent with rhizome and plant growth responses.

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Kitren Glozer, Joseph A. Grant, and William W. Coates

Moderate California winters often result in delayed, erratic or extended bloom, inadequate overlap with pollenizers, poor leafing-out, low fruit set, and irregular fruit maturity. In recent years, use of rest-breaking agents has become commonplace in California sweet cherry (Prunus avium L.) culture, mainly to promote earlier bloom and fruit maturity, but also to promote uniform flowering and overcome lack of marginal chilling. Variable responses by different cultivars and in different seasons may be due to different chilling requirements, despite little variation in genetic background for chill requirement in California's commercial cultivars. Other sources of variation include the activity of the rest-breaking agent used, concentration and carrier volume. A minimum amount of effective chill appears to be required for a given cultivar before rest-breaking agents can be effectively applied. This threshold, as exhibited by degree of response to treatment, can be an important indicator of when to spray. Method of measuring chill accumulation, and thus, timing of applications, varies by region and historic acceptance. California's tree fruit industry typically uses the 45 °F “chill hour” model. The Utah Chill Unit Model and the Modified 45 °F Chill Hours Model had not been thoroughly tested under California conditions nor with the rest-breaking chemicals that are in use today in California. We tested our research results against these models and the Dynamic Model developed in Israel and concluded that the Dynamic Model provided the best explanation of responses in our experimental trials. We have been developing recommendations for application of rest-breaking chemicals based on Dynamic Model chill portion accumulation.

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Monte L. Nesbitt, Robert C. Ebel, and William A. Dozier Jr

recommended per tree at planting is 45 L·hr, which is adequate for freeze protection for the first 4 years of growth and production. After the fourth growing season, a second sprinkler is added for each tree and placed within the established canopy having a

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Larry Parsons and Brian Boman

Best management practices (BMPs) started in Florida citrus (Citrus spp.) in the 1990s and have evolved to play a major role in production practices today. One of the earliest BMPs in Florida arose from concerns over nitrate-nitrogen concentrations in some surficial groundwater aquifers exceeding the 10 mg·L-1 drinking water standard. This occurred in an area of well-drained sandy soils known as the Central Florida Ridge that extends north and south through the central part of the Florida peninsula. State agencies could have used a strictly regulatory approach and restricted how much nitrogen growers could apply. Instead of setting arbitrary regulations, the agencies promoted a scientific-based BMP approach. A nitrogen BMP for Central Florida Ridge citrus was established, and research is now validating the earlier groundwater work on more grower field sites. The purpose of this BMP was to minimize the risk of leaching nitrates from fertilizer into the groundwater. Several important aspects of the BMP involve: 1) limiting the amount of nitrogen fertilizer applied at any one time, 2) increasing the frequency of fertilizer applications, 3) reducing fertilizer applications during the summer rainy season, and 4) managing irrigation to reduce leaching below the root zone. Since this Central Florida Ridge nitrogen BMP was established, major BMP actions to improve water quality and reduce the quantity of runoff water have taken place in the Indian River production area of Florida's east coast. BMPs continue to be set up in other parts of the state for a variety of plant and animal agricultural practices. In some cases, cost-share funds have been provided to help implement BMPs. With voluntary BMPs, growers have scientifically based guidelines, a waiver of liability, and an avoidance of arbitrary regulations.

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Brian K. Maynard and Nina L. Bassuk

In a study of stock plant etiolation and stem banding, stem cuttings of upright European hornbeam (Carpinus betulus L. `Fastigiata') were taken at 2-week intervals over 4 months following budbreak and rooted under intermittent mist for 30 days. Percent rooting and root counts declined with increasing cutting age. Stock plant etiolation and stem banding increased percent rooting and root counts throughout the study, with the combination of both treatments yielding the best rooting. In nontreated stems, > 75% rooting was achieved only within 4 weeks of budbreak. Etiolation and stem banding resulted in rooting ≥ 75% up to 3 months after budbreak. In two shading studies, stock plants were grown in a glass greenhouse under 0%, 50%, 75%, or 95% shade, or initially etiolated (100% shade) for 1.5 days. Cuttings were taken after 2.5 and 60 days and treated with IBA concentrations ranging from 0 to 4.9 mm before rooting under intermittent mist for 30 days. Percent rooting increased proportionally to the degree of shading, with a maximum response at 95% shade. Cuttings taken at 60 days were less responsive to etiolation and shading than those harvested at 25 days. Auxin concentration interacted with shading to yield, at 95% shade and 3.7 mm IBA, the highest rooting percentage and the greatest root counts and lengths. Light exclusion by etiolation, stem banding, or shading can extend the cutting propagation season by increasing rooting responses and increasing the sensitivity of stem cuttings to exogenously applied auxin. Chemical name used: 1H-indole-3-butyric acid (IBA).

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Michael W. Smith and William D. Goff

.e., when the nut is fully ripe) while trees are foliated and shucks are green, followed by a second harvest after a killing frost. Early season, top-quality pecans are in demand for direct market retailers that sell to customers before the Thanksgiving and

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Dinesh Phuyal, Thiago Assis Rodrigues Nogueira, Arun D. Jani, Davie M. Kadyampakeni, Kelly T. Morgan, and Rhuanito Soranz Ferrarezi

study was conducted for two seasons (2017–18 and 2018–19). Experimental design and treatments. The experiment was conducted in a split-plot design with four replications ( Table 1 ). We tested three planting densities {single row low-density (SR/LD) (4

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Brent L. Black, Tiffany Maughan, Christina Nolasco, and Blake Christensen

Intermountain West. High tunnels covered during the fall extend the production season beyond the first fall freezes and have been successfully used in New York ( Pritts, 2006 ), Pennsylvania ( Demchak et al., 2003 ), and Minnesota ( Yao and Rosen, 2011

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Tiffany L. Maughan, Kynda R. Curtis, Brent L. Black, and Daniel T. Drost

, combined with year-round consumer demand, create the need for extended fruit production into the off season. The climatic conditions in the Intermountain West require the use of season extension technologies so that growers may successfully supply markets

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Aaron Heinrich, Richard Smith, and Michael Cahn

, Partial-season, and Full-season treatments, respectively ( Table 2 ). Nitrate transported below 60 cm for the Full-season cover crop may be an overestimation of leaching for this treatment because cover crop roots may have extended below 60 cm and may have