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Melinda A. Miller-Butler, Barbara J. Smith, Kenneth J. Curry, and Eugene K. Blythe

anthracnose-resistant germplasm by Miller-Butler et al. (2018) . Disease severity refers to the amount of plant tissue that is diseased (necrotic) and may be expressed as the percentage of plant area destroyed by a pathogen. Percentage or numerical disease

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Christopher S. Cramer, Neel Kamal, and Narinder Singh

plant. Materials and Methods Eighteen commercial cultivars, three NMSU cultivars, and 17 NMSU experimental breeding lines were evaluated for IYS disease symptom severity and incidence, thrips number per plant, and leaf color and glossiness when they were

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Craig J. Frey, Xin Zhao, Jeffrey K. Brecht, Dustin M. Huff, and Zachary E. Black

in prolonged insect and disease incidence and greater severity. These challenges require growers to use production practices that maximize plant health and productivity. Low-cost high tunnel and grafting technologies may be used as integrative tools

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Rodulfo O. Pacumbaba Jr. and Caula A. Beyl

CD-ROM technology, scanners, and image capture software have enabled an alternate approach to determining disease severity. When estimating disease damage, information on disease severity may be as important as information on disease incidence. Disease incidence is the proportion of leaves infected on each tree; disease severity is the number of lesions or amount of tissue damage per tree. The Mielke and Langdon scale was used to determine the incidence of dogwood anthracnose on dogwoods under physiological stress; the CD-ROM system was used to determine the severity of the disease. Dogwood seedlings were exposed to four shade and three water levels for 12 weeks. Leaf images were stored on a photo-CD for image analysis. Water availability at 100% water-holding capacity significantly increased disease severity on dogwood leaves inoculated in vitro. The system allowed detection of a significant effect of water availability on susceptibility of the leaf to dogwood anthracnose that was not detected when incidence of infection was evaluated on a whole-plant basis

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A.D. Brede

A field study was conducted to evaluate the effect of tall fescue (Festuca arundinacea Schreb.) cultivar, seeding rate, N fertilization rate, and cutting height on the severity of dollar spot (Lanzia and Moellerodiscus spp.) disease incidence. All possible two-factor interactions among these four management factors were statistically significant when averaged over the 2 years of study. Disease severity tended to be lowest at low fescue seeding rate (2100 pure-live seeds/m*) at the lower (19 mm) height of cut. `Mustang', the turf-type cultivar with improved density, was more susceptible to dollar spot than `Kentucky-31', the common-type cultivar.

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Neel Kamal, Ashish Saxena, Robert L. Steiner, and Christopher S. Cramer

scales. Bulbs displaying symptoms of other fungal and bacterial diseases were discarded. Bulbs were examined visually and rated for black mold severity based on the area covered and bulb softness or degree of disease progression ( Kamal, 2007 ). Absence

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Sharon M. Tusiime, Gail R. Nonnecke, Dorothy M. Masinde, and Helen H. Jensen

, staking, and mulching and their impact on yield, disease severity, and gross margin. Evaluating horticultural practices for sustainable tomato production will enable small-landholder farmers to benefit from increased farm income and personal consumption

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Beiquan Mou, Steven T. Koike, and Lindsey J. du Toit

differences in disease severity among the cultivars. An additional series of spinach cultivars, including some with resistance to race 5 and race 6 of the downy mildew pathogen, were also susceptible to Stemphylium leaf spot ( Koike et al., 2001b ). In lettuce

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Catarina Saude, Mary Ruth McDonald, and Sean Westerveld

between CLS and foliar N concentrations in the field in another study, but this study did not examine the direct effect of N application rate on disease severity ( Tremblay and Charbonneau, 1993 ). Because excessive rates of fertilizers can be harmful to

Open access

Fulya Baysal-Gurel and Ravi Bika

mildew ( Lubell et al., 2011 ). The presence of powdery mildew in container-grown ‘Mindia Coppertina ® ’ ninebark was confirmed in a commercial nursery in Dekalb county, TN in 2016 ( Baysal-Gurel et al., 2020 ). The disease severity was 40%, and the