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Summary Goals: Bunch grape production in the southeastern United States is limited by the endemic bacterium Xylella fastidiosa, causal agent of Pierce’s disease (PD). University of California, Davis-bred PD-resistant 87.5% Vitis vinifera L. winegrape selections represent a new technology that can help sustain the viticulture industry in the southeastern U.S. by reducing pesticide inputs and diversifying grape production. PD-resistant vines were planted to determine viticultural performance and survival in central Alabama. We anticipated our results would indicate whether regional growers could feasibly grow PD-resistant, predominantly V. vinifera winegrapes under humid southeastern U.S. viticulture conditions. Key Findings: All evaluated selections grew vigorously under humid southeastern conditions. U0501-12 produced the highest pruning weight during the 2015 to 2016 period of study. U0502-10 was the most productive selection, as measured by total yield per vine, and had the largest clusters. Harvest soluble solids content was highest for selection U0501-12, while titratable acidity was lowest for U0502-01. All selections broke bud prior to historical late-spring frost-risk dates, although no injury was experienced in the years evaluated. U0502-10 began veraison between one and two months earlier compared to the other selections in both years. U0502-10 was also harvested 70 and 22 days prior to the next selection in 2015 and 2016, respectively. The experimental vines neither exhibited symptoms nor tested positive for PD during vine establishment. Under regional commercial management practices, no vine losses resulted from other pathogens. However, an aggressive disease management strategy will be mandatory to produce consistently clean fruit in the humid southeastern U.S. Impact and Significance: These results indicate grapevines with predominantly V. vinifera background can survive under humid viticulture conditions in central Alabama with the incorporation of alleles for PD resistance. Further research is necessary to refine management practices enabling sustainable production in the southeastern U.S. as PD-resistant grapevine cultivars become commercially available to regional producers.

Commercial kiwifruit production often requires substantial inputs for successful pollination. Determining the length of time that female flowers can be successfully pollinated can aid management decisions concerning pollination enhancement. The purpose of this research was to determine the effective pollination period (EPP) for ‘AU Golden Sunshine’ and ‘AU Fitzgerald’. Either 30 (2013) or 32 (2014, 2015) flowers of ‘AU Golden Sunshine’ were hand pollinated each day for 1 to 5 (2013) days after anthesis (DAA) or 1 to 7 DAA (2014, 2015), and then isolated to prevent open pollination. Anthesis was considered the day the flower opened. Similarly, ‘AU Fitzgerald’ flowers were pollinated and then isolated 1 to 6 DAA in 2013 and 1 to 7 DAA in 2015. For ‘AU Golden Sunshine’ in 2013, fruit set was consistent over the 5-day period, but fruit weight, fruit size index, and seed number decreased between 1 and 3 and 4 and 5 DAA. In 2014, fruit set decreased between 1 and 6 and 7 DAA, whereas fruit weight, fruit size index, and seed number each decreased in a linear trend. In 2015, fruit set also decreased between 1 and 6 and 7 DAA, whereas all other responses decreased linearly. Based on fruit set in 2014 and 2015, the EPP for ‘AU Golden Sunshine’ was 6 DAA. The EPP for ‘AU Fitzgerald’, however, was more variable. In 2013, fruit weight, fruit size index and seed number decreased between 1 and 4 and 5 and 6 DAA, suggesting that the EPP was 4 DAA. In 2015, fruit set remained consistent over the 7-day period with fruit weight, fruit size index, and seed number decreasing linearly. Differences in temperature and the alternate bearing tendency of kiwifruit species likely contributed to the discrepancies between the years for the EPP. For each cultivar, reductions in fruit weight, size, and seed number were observed before an observed decrease in fruit set. Greater fruit weight, size, and seed number were observed when flowers were pollinated within the first few DAA, with results varying thereafter.

The purpose of this research was to investigate the length of time that flowers of Actinidia chinensis ‘AU Golden Sunshine’ and Actinidia deliciosa ‘AU Fitzgerald’ can be successfully pollinated. This study consisted of isolating flowers 1 d prior to anthesis and hand-pollinating approximately 30 different flowers each day for 5-6 d following anthesis. Fruit set of ‘AU Golden Sunshine’ was similar for flowers pollinated up to 5 d following anthesis. Fruit set of ‘AU Fitzgerald’ was similar for flowers pollinated up to 5 d following anthesis, with reduced fruit set realized for flowers pollinated on day 6. Fruit weight and seed number of harvested fruit tended to decrease as flowers were pollinated later with respect to anthesis.

Alabama, Louisiana, and Mississippi are not often thought of as citrus-producing states. However, citrus has been grown in the coastal regions of these states since the late 19th century. With a climate cool enough for a suitable amount of acid to remain in the fruit for optimum flavor and for adequate peel color development, the northern coastal fringe of the Gulf of Mexico from Louisiana to northwestern Florida is particularly well suited for production of the satsuma mandarin (Citrus unshiu Marc.), one of the most cold-hardy commercial citrus species. There were once thousands of hectares of satsumas planted in this region. Although satsumas typically reach optimum eating quality before fall freezes along the Gulf Coast, periodic severe freezes, as well as the occasional hurricane, prevented a citrus industry of this magnitude from remaining viable. Though freeze injury remains the primary limiting factor for citrus production in this region, there is great local interest, and a small industry focused on local markets has endured. Satsuma remains the primary citrus grown along the Gulf Coast region, though sweet oranges account for a large portion of citrus sales in Louisiana. This paper reviews the history of satsumas on the Gulf Coast, covering past and present production, cultivation, freeze protection strategies, pest issues, and marketing.

Commercial blueberries, particularly Vaccinium corymbosum, have very specific needs for optimum growth; hence, growing sites are limited. Plants require acidic soil (pH 4.0–5.5), good drainage, thorough aeration, and a constant moderate amount of moisture. To overcome these restrictions, cultivars could be grafted onto a plant adapted to less desirable growing conditions. One potential rootstock is V. arboreum (sparkleberry), which has the ability to grow in many areas that could not be used for commercial blueberries. In the past, propagation of V. arboreum has been difficult, but there has not been much research on the subject. Currently, V. arboreum plants are commercially propagated from seeds. Asexual propagation techniques will be necessary for rapid clonal propagation of selected cultivars of V. arboreum. The current study evaluated the rooting percentage and growth characteristics of juvenile V. arboreum softwood, semi-hardwood, and hardwood cuttings subjected to a 10-second basal quick-dip in 0, 1000, 2500, 5000, or 7500 ppm IBA. Rooting percentage was not affected by IBA concentration. The factors that influenced rooting were the source of the cutting and the cutting type (softwood, semi-hardwood, or hardwood). Greatest rooting percentages were observed when softwood cuttings were used. There was also success using semi-hardwood cuttings from plants that had been cut back and allowed to sprout new shoots. The results of this experiment can be used to determine the feasibility of using stem cuttings to commercially propagate selected varieties of V. arboreum.

Satsuma growers in Alabama have used various orchard designs to minimize freeze damage. These designs include interplanting between pecan and pine trees, and planting behind windbreaks. Interplanting satsuma trees with pine trees resulted in warmer temperatures within the orchard, while the other orchard designs did not moderate orchard temperature during severe freeze events. Satsuma fruit harvested from plots shaded by pine tree canopies had higher soluble solids content and reduced fruit weight. Dense pine tree canopies can provide an insulating effect that reduces freeze damage and yield losses when severe freezes occur, but heavy shading can result in lower yields when damaging freezes do not occur.

Stilbene, ellagic acid, flavonol, and phenolic compounds were analyzed in 19 muscadine cultivars and 2 mus- cadine selections. Analysis was carried out on muscadine fruit skin, pulp and juice partitions. The major phenolics in muscadine juice, pulp and skins were identified by their retention times and characteristic spectra. Quantification was made by calibration curves of external standards for each of the analyzed compounds: trans and cis resveratrol, trans and cis piceid, ellagic acid, myricetin, quercetin and kaempferol. Free and total ellagic acid was observed in muscadine juice of eight cultivars, in amounts up to 54.0 � g/g in 'Ison' and 56.0 � g/g in 'Janet'. In the pulp, free ellagic acid was only ob- served in 3 cultivars, and total ellagic acid was observed in 8 cultivars in amounts up to 57.0 � g/g for 'Janet' and 77.0 � g/g for 'Southland'. Also in pulp, trans-resveratrol was observed in two cultivars, 'Eudora' and 'Janet' in amounts of 0.9 � g/g and 4.3 � g/g respectively. In muscadine skin, free and total ellagic acid, myricetin, quercetin and kaempferol were observed in all 21 cultivars analyzed and trans resveratrol was observed in all cultivars except 'Alachua'. Ellagic acid was the most abundant phenolic compound in muscadine grape skins. Total ellagic acid ranged from a low of 779.0 � g/g in 'Tara' to a high of 5,554.0 � g/g in 'Southland'. The presence of ellagic acid and other nutraceutical compounds in mus- cadine grape could add value and marketability to the crop due to the possible health benefits. This southern specialty crop could fast become the next "super fruit".

The total phenolic content and jasmonic acid (JA) content of foliage from gerbera (Gerbera jamesonii ‘Festival Salmon’) subjected to low and high fertilization rates were measured to determine effects of fertilization on phytochemicals implicated in defense of insect pests. Gerbera seedlings were fertilized with low (only supplied with initial fertilizer charge present in professional growing media) or high (200 mg·liter−1 N; recommended rate) fertilization rates. Since JA is induced in response to wounding, treatments consisted of ± mechanical wounding with a hemostat to one physiologically mature leaf and the subsequent harvest of that leaf at specified time intervals (0, 0.5, 1, 3, and 10 h) for JA quantification. Total phenolic content was measured in mature and newly formed leaves. Plants receiving low fertility had reduced aboveground dry mass, were deficient in nitrogen and phosphorous, and had approximately a 9-fold higher concentration of total phenolics in mature leaf tissue compared to high fertility plants. Newly formed leaves had greater concentrations of phenolics than mature leaves in low fertility plants. In response to wounding, JA accumulation was more rapid and higher concentrations of JA were sustained longer in low fertility plants than in high fertility plants. These results show that altering fertilization does affect phytochemicals implicated in defense against insect pests, and these chemical defenses are increased in the foliage of low fertility gerberas.

The oriental persimmon is native to China and is best adapted to areas with moderate winters and relatively mild summers. However, because of its low chilling requirement, persimmons will break dormancy during early warm periods only to be damaged by spring frosts later. This study was initiated to determine suitable cultivars for the gulf coast region. ‘Hana Fuyu’ was greatly affected by a freeze event. ‘Fuyu Imoto’ and ‘Matsumoto’ had numerous smaller fruit and were less affected by freeze events. Results indicated that persimmon cultivars are available that would be a good addition to growers who would like to diversify their fruit selection in the southern U.S.

This study evaluated the influence of insecticides on gas exchange, chlorophyll content, vegetative and floral development, and plant quality of gerbera (Gerbera jamesonii Bolus `Festival Salmon'). Insecticides from five chemical classes were applied weekly at 1× or 4× their respective recommended concentration. The insecticides used were abamectin (Avid), acephate (Orthene), bifenthrin (Talstar), clarified hydrophobic extract of neem oil (Triact), and spinosad (Conserve). Photosynthesis and stomatal conductance were reduced in plants treated with neem oil. Plants treated with neem oil flowered later—and at 4× the recommended label concentration had reduced growth, based on lower vegetative dry mass (DM) and total aboveground DM, reduced leaf area, thicker leaves (lower specific leaf area), higher chlorophyll content (basal leaves), and reduced flower production. Plants treated with acephate at 4× the recommended label concentration were of the lowest quality due to extensive phytotoxicity (leaf chlorosis). Plants treated with 1× or 4× abamectin or spinosad were of the highest quality due to no phytotoxicity and no thrips damage (thrips naturally migrated into the greenhouse). The control plants and plants treated with 1× bifenthrin had reduced quality because of thrips feeding damage; however gas exchange was not negatively affected.

Three separate studies were conducted to report the effects of kaolin applications (Surround WP) on southern highbush blueberries (Vaccinium corymbosum L.) and rabbiteye (V. ashei Reade) blueberries. When applied to mature blueberry plants, kaolin clay emulsion dried to form a white reflective film that affected bud development, fruit set and development, plant growth, and fruit yield, but had no effect on fruit quality parameters. When kaolin was applied before fruit set, yield was increased with no significant residue left on the fruit. Surround WP consistently reduced the number of flower thrips (Frankliniella spp.) within the canopy of rabbiteye blueberry plants by approximately 50%. Kaolin applications were not phytotoxic to blueberry buds, flowers, leaves, or fruit and were harmless to foraging bees.

This research focused on the influence of insecticides on gas exchange, chlorophyll content, vegetative and floral development, and overall plant quality of gerbera (Gerbera jamesonii var. `Festival Salmon'). Insecticides from five chemical classes were applied weekly at 1× and 4× the recommended concentrations. Insecticides used were: abamectin (Avid® 0.15 EC), acephate (Orthene® Turf, Tree & Ornamental Spray 97), bifenthrin (Talstar® Nursery Flowable), clarified hydrophobic extract of neem oil (Triact® 70), and spinosad (Conserve® SC). Phytotoxicity occurred in the form of leaf chlorosis on all acephate treatments, with the greatest damage occurring at the 4× concentration. Photosynthesis and stomatal conductance were significantly reduced in plants treated with neem oil extract. Plants treated with the neem oil extract (1× and 4×) flowered later and had reduced growth [lower shoot dry mass (DM) and total DM]. Plants that received 4× the recommended concentration of neem oil extract had reduced leaf area, thicker leaves (lower specific leaf area), higher leaf chlorophyll content, and reduced flower production, as determined by flower number and flower DM. Plants treated with acephate 4× concentration were the lowest quality plants due to extensive phytotoxicity (leaf burn), which also reduced photosynthesis. The highest quality plants were treated with spinosad and abamectin due to zero phytotoxicity and/or no thrips damage (thrips naturally migrated into the greenhouse). The control plants and plants treated with bifenthrin 1× were not marketable due to thrips damage; however, plant growth characteristics and gas exchange were not statistically different.

This research focused on the effects of nitrogen fertilization on jasmonic acid accumulation and total phenolic concentrations in gerbera. The phytohormone jasmonic acid is known to regulate many plant responses, including inducible defenses against insect herbivory. Phenolics are constitutive secondary metabolites that have been shown to negatively affect insect feeding. Gerbera jamesonii `Festival Salmon Rose' plants were grown in a growth chamber and subjected to either low fertilization (only supplied with initial fertilizer charge present in professional growing media) or high fertilization (recommended rate = 200 mg·L-1 N). Plants were fertilized with 200 mL of a 15N–7P–14K fertilizer at 0 or 200 mg·L-1 N at each watering (as needed). Treatments consisted of ±mechanical wounding with a hemostat to one physiologically mature leaf and the subsequent harvest of that leaf at specified time intervals for jasmonic acid quantification. Total phenolics were measured in physiologically mature and young leaves harvested 0 and 10 hours after ±mechanical wounding. Low-fertility plants had reduced aboveground dry mass, were deficient in nitrogen and phosphorus, and had about a 10× higher concentration of total phenolics when compared to high fertility plants. In low-fertility plants, young leaves had greater concentrations of phenolics compared to physiologically mature leaves. There were no differences in total phenolics due to wounding. The effect of nitrogen fertilization on jasmonic acid accumulation will also be discussed.

This research focused on the influence of insecticides on plant growth, gas exchange, rate of flowering, and chlorophyll content of chrysanthemum (Dendranthema grandiflora Tzvelev cv. Charm) grown according to recommended procedures for pot plant production. Five insecticides were applied at recommended concentrations at three different frequencies: weekly (7 days), bi-weekly (14 days), or monthly (28 days). A separate treatment was applied weekly at 4× the recommended concentration. Insecticides used were: acephate (Orthene®) Turf, Tree & Ornamental Spray 97), bifenthrin (Talstar®) Flowable), endosulfan (Thiodan®) 50 WP), imidacloprid (Marathon®) II), and spinosad (Conserve®) SC). Phytotoxicity occurred in the form of leaf burn on all acephate treatments, with the greatest damage occurring at the 4× concentration. Photosynthesis and stomatal conductance were influenced primarily by the degree of aphid and/or spider mite infestation—except for acephate and endosulfan treatments (weekly and 4×), which had reduced photosynthesis with minimal insect infestations. Plants receiving imadacloprid monthly had the greatest leaf dry mass (DM). Plants treated with acephate had lower leaf and stem DM with bi-weekly and 4× treatments. Spinosad treatments at recommended concentrations had reduced stem DM, in part due to aphid infestations. The flower DM was not significantly different among treatments. There were treatment differences in chlorophyll content as measured with a SPAD-502 portable chlorophyll meter.