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Four greenhouse leaf inoculation methods for screening Japanese plum (Prunus salicina L. and hybrids) for resistance to Xanthomonas campestris pv. pruni (Smith) Dye were compared for repeatability, ability to differentiate among plant genotype responses, and correlations with field ratings. Clonally propagated trees were inoculated artificially in a greenhouse by immersing leaves in 2.5 × 108 cfu/ml inoculum (DIP), rubbing the adaxial side of leaves with a slurry of 2.5 × 108 cfu/ml inoculum and Carborundum powder (CARB), infiltrating leaves with 5 × 105 cfu/ml inoculum using a needle-less syringe (INFS), and infiltrating with 5 × 106 cfu/ml inoculum (INF6). No greenhouse method was superior in all assessment categories. The CARB method was most repeatable (t = 0.78) but had a low Spearman's correlation (rs = 0.29), indicating that greenhouse rankings did not correspond closely with field rankings. The INF6 method was unsuitable because it did not differentiate between plant genotypes. The DIP method appeared most suitable, having moderate repeatability (t = 0.46) for four observations per leaf and moderate Spearman's correlation with field performance (rs = 0.56). The INF5 method may be appropriate for identifying bacterial spot resistance that is associated with resistance in the leaf mesophyll.

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Ammonium lignosulfonate (ALS) is a liquid waste by-product of pulp and paper industry that may be a source of organic fertilizer. Four plots each of tomato, pepper, broccoli, and corn were set up in a randomized block design on the AAFC-SCPFRC farm in the Spring 1998. Treatments were untreated control, 0.5% (v/w) ALS, and 1% (v/w) ALS. Soil samples were taken at 0, 2, 4, 8, and 22 weeks after amendment incorporation and analyzed for pH, microbial population, and water soluble ions. Soil temperature was measured at 8-cm depth. Leaf chlorophyll content was measured at four sampling dates. Tomato and pepper fruit were evaluated for symptoms of diseases. Soil temperature in 0.5% and 1.% ALS treatments were 2 and 7 °C warmer, respectively, than the control. Soil pH was lower in ALS-treated plots. 1% ALS caused more than 10-fold increase in bacterial population. Fungal populations in both 0.5% and 1% ALS treatments were 10- to 100-fold higher than control soil and continued to be higher to the last sampling date. Weeds were reduced by more than 50% by 0.5% or 1% ALS treatments. Both ALS rates caused an initial increase in NH4, NO3, NO2, K, Na, Cl, PO4, Ca, and SO4. NH4 and SO4 remained elevated for 22 weeks in both ALS treatments. ALS slightly increased chlorophyll content in tomato, pepper, and corn, but not in broccoli plants. The number of diseased tomato fruit in ALS plots were reduced by 50% to 70%. Bacterial spot decreased by more than 50% in both ALS-treated plots, while anthracnose declined by 50% to 75%. There were no significant differences in early and total yield of tomato, peppers, and corn. Early broccoli yield decreased in ALS treatments, while total yield increased over that of control in both ALS treatments.

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IPM teams from Alabama, North Florida, Georgia, Kentucky, North Carolina, South Carolina, and Tennessee composed of growers, private consultants, and faculty defined IPM on fresh-market tomatoes and created a survey from this definition to evaluate the level of IPM used by growers in the southeastern U.S. The survey included three sections: cultural practices, pesticide application techniques, and specific pest management practices, and was distributed to tomato growers in the region by mail, at county meetings, and through other relevant venues. Additionally, growers were asked to identify problems (insect, disease, and nonpest, i.e., cultural) and beneficial technology or research developments. Results of the survey revealed that in North Florida, Georgia, Kentucky, North Carolina, and South Carolina more than 75% of the tomato acreage is in the medium or high IPM category. These states have met or exceeded the State IPM teams' criteria for practicing IPM and have met the Federal mandate of IPM implementation on 75% of the fresh-market tomato cropland. Tomato producers listed early blight, late blight and bacterial spot as their main disease problems; tomato fruit worm, thrips, and aphids as their primary insect problems; and poor weather conditions, government regulation, and labor issues as their primary nonpest problems. Producers throughout the region felt that the development of resistant varieties would help them increase production the most. The State IPM teams outlined a clear definition of IPM in fresh-market tomato production and the survey results established a baseline that can be used to measure the success of programs to increase IPM adoption. The results will aid in focusing the Extension/research agenda in the universities in the Southeast.

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Production of red bell peppers (Capsicum annuum L. cv. King Arthur) is relatively new to Quebec, and management techniques need to be further developed in terms of insect and disease control as well as fertigation techniques. The purpose of the experiment was to compare the fertigation of peppers using either the conventional method (weekly fertigation) or fertigation based on the readings of the SPAD 502 chlorophyll meter. The experiment compared the effects of these fertigation treatments, with respect to insects and diseases, on either a silver or black mulch. The study done in 1995, demonstrated that using the chlorophyll meter saved 28 kg N/ha compared to the weekly fertigated plants. However, this decrease did not affect the population of insects or the disease incidence on the plants. The main differences occurred between the black and silver mulch treatments for aphid populations. Plants on silver mulch had significantly lower numbers of aphids than the other treatments. Plants on black mulch also had low aphid population compared to plants grown on bare soil. The relationship between silver mulch and viruses or tarnished plant bug were not as apparent. However, the viral infections and tarnished plant bug populations on the plants tended to be lower than those on most of the black mulch treatments. Sunscald was not influenced by mulch or fertigation treatments. This may be partly attributed to the amount of leaf area. The number of fruit invaded by European corn borer was too low to draw any conclusions. Blossom end rot, sclerotinia, and bacterial spot were not present in the field in the 1995 season. The results from the 1996 season should further elucidate these results.

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these trials. When averaged over the four trials in 2 years, ‘Plum Regal’ was higher than ‘Plum Crimson’ in total and marketable grade yields, percent marketable grade, and fruit size ( Table 1 ). Bacterial spot was a problem in these trials, and ‘Plum

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hang on the tree for an extended period. The freestone fruit develops excellent melting texture and rich flavor as it ripens. Trees appear to be highly resistant to bacterial spot disease based on little visualized symptoms on fruit and leaves

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be moderately resistant to bacterial spot disease. Blossoms have large, showy pink petals and are self-fertile. Trees bloom slightly after ‘Sunprince’ and before ‘Cresthaven’, requiring ≈800 to 850 h of chilling below 7 °C (45 °F) to break the bud

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. All three cultivars were field grown and evaluated for 9 years and showed tolerance to common crape myrtle diseases such as bacterial spot, powdery mildew, Cercospora leaf spot, and “Rabbit Tracks” disorder. Origin ‘Miss Gail’ resulted from a cross

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://extension.uga.edu/publications/detail.html?number=B1171 ), primarily to manage pests and fungal diseases on fruit or control weeds. No bactericides were used on any test trees or at any locations, to maximize bacterial spot expression. Trees appeared to be highly resistant to bacterial spot disease

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. Trees showed little bacterial spot symptoms on fruit or leaves throughout the evaluation years, suggesting ‘Crimson Joy’ is highly resistant to the disease. No virus symptoms have been observed. Trees have not been tested extensively in northern climates

Open Access