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Twenty-eight bell pepper cultivars and breeding lines were evaluated for resistance to the crown and stem rot phase of Phytophthora blight (Phytophthora capsici) and for silvering of fruit at two sites in southern New Jersey in 2005. A randomized complete block design with four replications was setup at Rutgers Agricultural Research and Extension Center (RAREC), Bridgeton, New Jersey and at an on-farm site in Vineland, NJ. Number and weight of fruit with silvering varied significantly depending on pepper line, harvest date, and location. Percentage of phytophthora-infected plants ranged from 0% to 26% at RAREC and 0% to 78% at the on-farm site depending on pepper line. In some cases, new breeding lines exhibited levels of Phytophthora-resistance comparable to the resistant cultivar Paladin. Depending on pepper line, percentage of harvested fruit with silvering decreased with later harvest dates. The percentage of fruit with silvering ranged from 0% to 92% during first harvest, 1% to 56% during second harvest and from 5% to 35% during third harvest at RAREC, and from 0% to 22% during second and 0% to 15% during third harvest at the on-farm site depending on pepper line. Less fruit silvering developed in lines with no resistance or tolerance to P. capsici. Reports have suggested that phytophthora-resistance is linked to increased silvering in fruit. Silvering in Paladin was 66%, 56%, and 35% compared to only 0%, 1%, and 5% in Camelot (susceptible cultivar) during each harvest at RAREC and was 22% and 15% in Paladin compared to 0% in Camelot at the on-farm site. Interestingly, silvering was lower when pepper lines were grown on high-ridged bare soil beds with overhead irrigation (on-farm site) compared to same pepper lines grown on black plastic mulch with drip irrigation (RAREC).

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A study was conducted in the greenhouse to investigate the effects of red light (600-700 nm) on the subsequent occurrence of seedling infection of bell pepper, pumpkin, and tomato caused by Phytophthora capsici. Three- or 4-week-old seedlings were inoculated with zoospores or transplanted into pots filled with artificially infested soil mix. Red light treatment of seedlings reduced Phytophthora damping-off by up to 79%. Only 21% to 36% of red light-treated seedlings became infected, whereas 78% to 100% of the control seedlings, grown either in natural daylight (NDL) or under white light (WL), became infected and died. The height, and fresh and dry weight of seedlings treated with red light were significantly higher than those grown under NDL or WL.

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Watermelon (Citrullus lanatus [Thunb.] Matsum & Nakai) fruit are affected by a number of preharvest disorders that may limit their marketability and thereby restrict economic returns to growers. Pathogenic diseases discussed include bacterial rind necrosis (Erwinia sp.), bacterial fruit blotch [Acidovorax avenae subsp. citrulli (Schaad et al.) Willems et al.], anthracnose [Colletotrichum orbiculare (Berk & Mont.) Arx. syn. C. legenarium (Pass.) Ellis & Halst], gummy stem blight/black rot [Didymella bryoniae (Auersw.) Rehm], and phytophthora fruit rot (Phytophthora capsici Leonian). One insect-mediated disorder, rindworm damage is discussed. Physiological disorders considered are blossom-end rot, bottleneck, and sunburn. Additionally, cross stitch, greasy spot, and target cluster, disorders of unknown origin are discussed. Each defect is shown in color for easy identification.

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The inheritance of resistance to Phytophthora capsici Leonian root rot and foliar blight was compared in two different Capsicum annuum L. var. annuum pod types. The seedling was screened for phytophthora root rot, while a genetically identical stem cutting was screened for phytophthora foliar blight to determine if the same gene(s) confer resistance to both disease syndromes. The susceptible parents were `Keystone Resistant Giant #3' (`Keystone'), a bell pepper type, and `Early Jalapeño', while `Criollo de Morelos-334' was the resistant parent. Resistance was observed in both F1 populations screened for phytophthora root and foliar infection indicating dominance for resistance. Reciprocal effects were not detected. To determine if the same gene(s) conferred root rot and foliar resistance, root rot screening results were matched to the corresponding foliar blight stem cutting reaction. The segregation of resistance in the F2 generations was dependent on the susceptible parent. In the F2 generation derived from `Early Jalapeño', root rot resistance and foliar blight resistance segregated in a 9:3:3:1 (root resistant/foliar resistant: root resistant/foliar susceptible: root susceptible/foliar resistant: root susceptible/foliar susceptible) ratio. One independent, dominant gene was necessary for root rot resistance, and a different independent, dominant gene was needed for foliar blight resistance. In the F2 generation derived from `Keystone', root rot and foliar blight resistance segregated in a 7:2:2:5 (root resistant/foliar resistant: root resistant/foliar susceptible: root susceptible/foliar resistant: root susceptible/foliar susceptible) ratio. This segregation ratio is expected when one dominant gene is required for root resistance, and a different dominant gene is required for foliar resistance. In addition to these two genes, at least one dominant allele of a third gene must be present for expression of root rot and foliar blight resistance.

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An inexpensive, rapid, and reliable seedling screening technique was developed to identify sources of resistance to foliar blight of Capsicum annuum L. caused by the fungal pathogen Phytophthora capsici Leon. Leaf surfaces of test plants were inoculated with 500 to 1000 zoospores prepared in distilled water. Seedlings were incubated for 5 days in an easy-to-construct dew chamber and observed for symptom development. `Criollo de Morelos 334' chile seedlings, a Mexican land race resistant to root rot caused by the same fungal pathogen, were highly resistant to foliar blight. All commercial cultivars tested in this study, however, were highly susceptible. No root rot symptoms were observed in any of the foliar-inoculated plants.

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Long green/red peppers (chile), one of about 20 different domesticated Capsicum annuum L. types, has for many years been associated with the green fresh market, processing and dehydrated red chile Industry in the southwest. Increased demand for green chile and for high red color chile powder, high vitamin C, and low caloric pepper product has stimulated production in Texas and other areas throughout the world. All known commercial long green/red chile are susceptible to viral, fungal and bacterial diseases. These pathogens are limiting factors in most pepper production areas throughout the world. The Texas Agricultural Experiment Station at Weslaco has developed several hundred mildly pungent, high red color inbred lines with resistance to tobacco etch virus, pepper mottle virus, potato virus Y, tobacco mosaic virus, tobacco ringspot virus, cucumber mosaic virus and Phytophthora capsici. Disease resistant lines of mildly pungent long fruited, medium thick wall chile are being advanced to cultivar status.

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Phytophthora capsici fruit rot is an increasingly serious disease affecting cucumber production throughout the Eastern U.S. The absence of genetically resistant cultivars and rapid development of fungicide resistance makes it imperative to develop integrated disease management strategies. Cucumber fruits which come in direct contact with the soil-borne pathogen are usually located under the canopy where moist, warm conditions favor disease development. We sought to examine whether variations in plant architecture traits that influence canopy structure or fruit contact with the soil make conditions less favorable for disease development. As a `proof of concept' to test whether an altered canopy could facilitate P. capsici control, we tested the effect of increased row spacing and trellis culture on disease occurrence in the pickling cucumber `Vlaspik.' Trellis plots indicated that removal of fruit contact from soil reduced disease occurrence. Currently available variation in plant architecture was tested using nearly-isogenic genotypes varying for indeterminate (De), determinate (de), standard leaf (LL), and little leaf (ll) traits. Although differences were observed in peak mid-day temperatures under the different canopies, there were not differences in disease occurrence among the genotypes. A collection of 150 diverse cucumber accessions identified to serve as a representative sample of the germplasm, was observed for possible variation in plant architecture. Variation was observed for an array of traits including main stem length, internode length, leaf length and width, and number of branches. Interesting types that may allow for more open canopies include reduced branching habit and compact/bushy growth.

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The oomycete fungus Phytophthora capsici Leon. is known to be a limiting factor of chile pepper (Capsicum spp.) production around the world. The genetics of the resistance is becoming better understood due to the specific nature of the host–pathogen interaction; i.e., all plant organs are subject to infection. This study determined whether stem blight was the same disease syndrome as root rot or foliar blight. Stem cuttings of a segregating F2 population and testcross progeny facilitated the ability to screen for two disease syndromes concurrently. When the three disease syndromes were compared separately, the F2 populations fit a 3R:1S ratio and the testcross progeny fit a 1R:1S ratio. When comparative studies were performed (stem vs. foliar and stem vs. root), the F2 populations fit a 9R/R:3R/S:3S/R:1S/S ratio and the testcross fit a 1R/R:1R/S:1S/R:1S/S ratio. These ratios are consistent of a single gene controlling the resistance of each system. Therefore, Phytophthora stem blight, root rot, and foliar blight are three separate disease syndromes.

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garden are used fresh in salsa, sliced into rings for use with nachos, or pickled for later use. Soilborne diseases, like phytophthora blight ( Phytophthora capsici Leon.), continue to threaten the jalapeño crop in the United States and globally. The use

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production was induced by culturing isolates on V8A plates under ambient lighting. Heterothallic species were paired with Phytophthora capsici tester isolates CBS 121656 (A1) or CBS 121657(A2) and incubated in the dark for 7 to 14 d. Oospore production and

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