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Systemic acquired resistance (SAR) is a physiological defense response in plants conferring broad spectrum resistance to pathogens. SAR is inducible through infection by necrotizing pathogens or chemical inducers and involves the systemic activation of defense related genes. Our objectives were to evaluate resistance expression to phytophthora soft rot fruit in cucumber in response to increasing concentrations of 2,6 dichloroisonicotinic acid (INA) and benzo (1,2,3)thiadiazole-7-carbothioc acid S-methyl ester (BTH) by foliar applications. Excised leaves exhibited a resistance response to foliar applications of all concentrations of INA and BTH tested when challenge inoculated with Colletotrichum lagenarium. There was increasing benefit with increasing concentration of each chemical applied. Harvested cucumber fruit, 3.4 to 4.5 cm in diameter, were challenge inoculated with Phytophthora capsici; there were no significant chemical and rate interactions in terms of internal lesion measurements. Overall, INA consistently reduced lesion size in cucumber fruit. A bioassay conducted on fruit of different maturity levels, as defined by fruit diameter, revealed that larger sized fruit (4 to 5 cm) were more resistant to fruit rot. Fruit with diameters of 3 to 4 cm from plots treated with BTH showed little resistance as compared to the control and fruit from the same treatment with diameters of 2 to 3 cm. Fruit from plots treated with INA had at least 50% reduction in lesion size than the control. It is unclear if these differences were attributable to changes in physiological or anatomical factors. The true importance of these results should be interpreted with caution. Yield studies have not been conducted, and thus, with the experienced stunting, treatment with 100 ppm INA would be expected to lower yield and perhaps fruit quality. Determination of the optimal application regime and other cultural factors will provide broad control of plant diseases.

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Phytophthora capsici. Resistance in these germplasm lines is expressed as significantly reduced to practically no lesion development, rot, or pathogen sporulation on the fruit compared with large lesions, severe rot, and heavy sporulation on commercial

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Increasing disposal problems with polyethylene (PL) mulch and greater availability of compost prompted an investigation into the effects of using compost as a mulch on horizontal raised bed surfaces with living mulches (LMs) on vertical surfaces. Wood chips (WC), sewage sludge-yard trimming (SY) compost, and municipal solid waste (MW) compost were applied at 224 t·ha-1 on bed surfaces. Sod strips of `Jade' (JD) or `Floratam' (FT) St. Augustinegrass (Stenotaphrum secundatum Kuntze) or perennial peanut (Arachis glabrata Benth.) (PP) or seeds of a small, seed-propagated forage peanut (Arachis sp.) (SP) were established on the vertical sides of the raised beds before transplanting bell pepper (Capsicum annuum L.) into the beds. Phytophthora capsici reduced pepper plant stand in PL-mulched plots compared with organic mulch (OM) and LM. Despite the stand reduction, total pepper yields were highest in PL plots and, in the OM plots, decreased in the order SY > MW > WC. Early fruit yields and yield per plant were highest from plants in PL plots followed by SY. Among LMs, plants in SP plots produced highest early yields and FT produced the lowest. Plants in PL plots produced the largest fruit. When the same plots were seeded with winter (butternut) squash (Cucurbita pepo L.), plant stands were higher in MW than WC and SY. Squash yields were similar between PL and OM plots.

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Michigan is the national leader for pickling cucumber production. However, over the last few years growers have witnessed a considerable decline in marketable yield, mainly attributed to fruit rot caused by Phytophthora capsici. Phytophtora develops rapidly under high relative humidity, a situation commonly found with narrow rows. Growers are interested in using wider rows but would like to know if there are any associated yield reductions. This study was conducted in 2003 to measure the effects of cucumber plant populations on canopy dynamics and fruit yield. Cucumbers were grown with between-row spacing of 30.5, 45.7, 61.0, and 76.2 cm, and in-row spacing of 10.2, 12.7, and 15.2 cm. A split-plot design with four replications was used. Row spacing was the main plot factor, and in-row spacing the subplot factor. Soil covered by plant canopy was monitored throughout the growing season using digital image analysis techniques. At harvest, the number of fruits per plant and marketable yield for the different grades were measured. Cucumber canopy remained open during the major part of the growing season when wide rows (61.0 and 76.2 cm) were used. The number of fruits per plant increased from an average of 1.5 fruits at 30.5 cm to 2.0 fruits per plant at 61.0 cm. Further widening of row spacing to 76.2 cm slightly reduced the number of fruits per plant. Therefore, the optimum row spacing would be 61.0 cm if the number of fruits per plant was the only parameter being measured. Cucumber marketable yield was similar with 30.5, 45.7, and 61.0 cm spacing between the rows. With 76.2-cm rows, yield reduced slightly. These results suggest that cucumber plant density can be reduced substantial with limited yield penalty.

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The impact of pesticide application technology and crop stand density on bell pepper production was evaluated in a series of field trials, during 2004 and 2005, at the North Central Agricultural Research Station, Fremont, Ohio. In 2004, one trial tested three sprayers, at a speed of 8 and 4 mph, using insecticides at half the recommended rate and one treatment at full rate. Sprayers evaluated included an air-assisted electrostatic sprayer, a Cagle sprayer equipped with AI-11005 or AI-110025 nozzles, and an air-blast sprayer with XR-1003-VS or XR-110015-VS nozzles. In 2005, one experiment tested the interaction of two application technologies, three planting distances within row, and single vs. twin rows. Another experiment compared the Cagle sprayer (with TJ60-11003 or AI-110025 nozzles) and the airblast sprayer (with XR-110015-VS nozzles), at a speed of 4 mph, and insecticides at half the recommended rate. In 2004, the Cagle sprayer with air-induction nozzle, half rate, at 8 mph obtained the highest fruit yield. There was not significant improvement in European corn borer control by applying insecticides at full rate with the Cagle sprayer and all treatments achieved significantly better bacterial soft rot control than the untreated control. In 2005, the trials were terminated early due to crop destruction by Phytophthora capsici. Red fruit weighed less at high than at medium or low plant stand densities. Clean yield of red fruit was significantly greater in single rows than in twin rows. Marketable yield of green fruit was greater using the TJ60-11003 than using the AI-110025 nozzles.

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At the Vegetable and Fruit Improvement Center, plant breeding has produced pepper lines with enhanced beneficial phytochemical levels. TAM `Dulcito' is a new jalapeño cultivar with no detectable levels of capsaicin, but increased levels of lutein. In greenhouse cultivation, it contained 122 ppm of this important human health-related compound, which aids in prevention of macular degeneration. This is a significant improvement over popular cultivars, such as `Grande', which contained 25 ppm or less. In addition to improved lutein levels, `Dulcito' also possesses resistance to three important potyviruses: TEV, PepMoV, and PVY. In field trials at Weslaco, Texas, `Dulcito' outyielded both TAM `Mild Jalapeño 2', and `Mitla'. This new cultivar produces a concentrated set of large, thick-fleshed fruit with few cuticular cracks. Because of its lack of pungency, it should be useful for the processing industry. TAM `Tropic Bell' is a medium-sized, blocky bell with enhanced levels of both ascorbic acid and lutein compared to other cultivars. Grown under greenhouse conditions, it contained 100 ppm lutein compared to 6 ppm in `Jupiter'. It also contained 660 ppm ascorbic acid at the green stage, compared to less than 100 ppm for three commercial bell cultivars tested. `Tropic Bell' produced yields equal to both `Valiant' and `Summer Sweet' commercial hybrids at Weslaco. Fruit of `Tropic Bell' were slightly smaller than the hybrid cultivars. TAM `Tropic Bell' possesses resistance to the same three potyviruses as `Dulcito' and demonstrated excellent tolerance to Phytophthora capsici in a controlled inoculation. These two new cultivars will be useful for production in locations with high potyvirus pressure or as specialty market items for health-conscious consumers.

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Cornus florida L. ( Brown et al., 2019 ) and Persea americana Mill. ( Belisle et al., 2019 ), Phytophthora capsici Leonian on Capsicum annuum L. ( Ji and Csinos, 2015 ; Miao et al., 2016 ), Phytophthora infestans (Mont.) De Barry on S

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( Podosphaera xanthii ) and Phytophthora capsica that cause Phytophthora fruit rot. In comparison, the watermelon cultivar Mickey Lee and watermelon germplasm line USVL677-PMS are highly susceptible to P. xanthii and P. capsici . The hypocotyls, cotyledons

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Pennsylvania Department of Agriculture 2009 Fungicides for common PA diseases in conifer nurseries. Pennsylvania Dept. Agr., Harrisburg, PA Quesada-Ocampo, L.M. Fulbright, D.W. Hausbeck, M.K. 2009 Susceptibility of fraser fir to Phytophthora capsici Plant Dis

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The experiment was conducted at the Cunningham Research Station in Kinston, N.C. (coordinates: N35 18.372; W77 34.937), on Goldsboro loamy sand. Three cultural systems (bare ground + overhead irrigation bare ground + drip irrigation, black plastic + drip irrigation) and seven fungicide treatments were evaluated in a split-plot design with cultural system as the main plot and fungicide treatments as subplots. The cultivar used was `Mickey Lee'. The trial was installed 18 July. Soil moisture was monitored in each of the cultural regimes using soil moisture sensors (Spectrum Technologies, Inc, Plainfield, IL) and rain gauges. The cultural systems using drip irrigation were irrigated to 10 cb starting when soil moisture reached 40 cb. Overhead irrigation was used to maintain at least 2 inches per week total precipitation beginning 12 Aug. Cultural systems and fungicide treatments were replicated 4 times. To prevent gummy stem blight and powdery mildew, Pristine (14.5 oz/acre) and Quintec (6 oz/acre) were alternated with Bravo Weather Stik (2 pt/acre) and Flint (4 oz/acre) on a 7-day interval, beginning 16 Aug. Experimental fungicide treatments were applied using a CO2 backpack sprayer equipped with a 3-nozzle (19-inch spacing) handheld boom with hollow cone nozzles (TXVS-26) delivering 40 gal/acre at 45 psi. Treatments were initiated when the largest fruit were about 6 inches in diameter. All treatments were applied on a 7-day interval with applications on 25 Aug. and 2, 9, 16, and 23 Sept. Plots were inoculated on 12 and 19 Sept. by hand-scattering 0.5 lb of 1-cm cubes of naturally P. capcisi-infected acorn squash fruit per plot. Disease severity was evaluated on 26 Sept. as fruit rot incidence and percent foliar necrosis. Captan was most effective in suppressing fruit rot regardless of cultural regime. Captan and NOA-446510 were both effective in reducing vine collapse across all cultural regimes. Incidence of fruit decay was significantly greater in the bare ground + overhead irrigation (overhead) cultural regime while plasticulture (plastic) and bare ground + drip irrigation (drip) resulted in similar levels of fruit decay and vine collapse. No interaction of cultural regime with treatment was detected. Watermelon stems and foliage are typically very resistant to Phytophthora blight, but significant vine collapse occurred in many plots. P. capsici was consistently isolated from diseased foliage and stems and is considered the primary cause of vine collapse.

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