Investigation of TOM-CAST, Staking, and Mulch for Managing Tomato Diseases

NYS IPM Type: Project ReportThe objective of one experiment conducted in 1997 was to compare two versions of TOM-CAST, a weather-based disease forecasting system, to a weekly spray program for managing early blight in fresh-market tomatoes. Bravo Ultrex and Bravo C/M were used

Evaluation of Harpin for the Control of Insect-Vectored Bacterial Wilt of Pumpkin and Testing of PMR-Pumpkin and Squash Varieties for Their Reaction to Beetle Feeding Activity and Bacterial Wilt Inoculations

NYS IPM Type: Project ReportThe goals of this project were 1) to determine if harpin can suppress the transmission of bacterial wilt (BW) vectored by cucumber beetles and 2) to compare cucurbit crops and varieties for their attractiveness to cucumber beetles and susceptibility to bacterial wilt

Investigation of TOM-CAST, Staking, and Mulch for Managing Tomato Diseases

NYS IPM Type: Project ReportThe objective of one experiment conducted in 1998 was to compare two versions of TOM-CAST, a weather-based disease forecasting system, to a weekly spray program for managing early blight in fresh-market tomatoes. Bravo Ultrex alone or in alternation with Quadris were used. All three spray programs were started on 14 July after 37 disease severity values (DSVs) had accumulated from transplanting, which was 5 weeks before the first harvest

Evaluation of Pepper Cultivars for Tolerance to Phytophthora capsici and Impact of Messenger on Tolerance and Yield

ReportThe goal of this project was to demonstrate and evaluate commercially available pepper cultivars for tolerance to Phytophthora capsici crown and fruit rot. Some of the cultivars were treated with a compound designed to enhance the ability of plants to resist diseases, to see if disease tolerance or yield could be improved. Of the tested cultivars, Paladin and Aristotle showed good tolerance to this disease, but disease pressure this year was light. Yields and earliness were generally similar across the 4 locations of testing, indicating that these varieties were fairly stable in their performance and may be good candidates for use in fields where the disease is problematic. Using Messenger, one crop stimulant, did not enhance yield or disease resistance of these peppers. The added labor and expense for application of this material could not be justified through these experiments

Evaluation of Two Commercially Available Composts for Managing Phytophthora Fruit Rot of Pumpkin

ReportThe goal of this project was to evaluate commercially available composts for managing Phytophthora fruit rot of pumpkin. Five composts were screened for disease suppressiveness against common soil borne disease organisms in the greenhouse. One product stood out as highly suppressive. This compost (Nutribrew) was then applied to two fields with a history of Phytophthora capsici. In one field, no disease occurred. Pumpkin growth and yield was significantly improved where compost was applied, and 20 tons/a was adequate to achieve this improvement. The compost contributed to both nutrients as well as moisture conservation. In the other field, the disease pressure was high, and compost applications did not reduce the disease level. These results may suggest the need for several years of application before diseases may be reduced

Improving the Management of Powdery Mildew of Cucurbits

NYS IPM Type: Project ReportThe primary goals of this project were to evaluate powdery mildew resistant (PMR) pumpkins and to determine if there is a benefit of applying fungicides to PMR pumpkins. Through this project, resistant varieties of pumpkin were shown to be an effective way to manage powdery mildew; however, challenges were also revealed. Two powdery mildew resistant (PMR) varieties were commercially available when this study was conducted. Magic Lantern was shown to be less resistant than an experimental pumpkin line being developed by Harris Moran (HMX 6687) or a Cornell line (98-714). There was a benefit to applying fungicides to Magic Lantern. An integrated program was highly effective: there was significantly less powdery mildew on PMR Magic Lantern receiving a 14-day fungicide program than on susceptible Wizard receiving a 7-day fungicide program. The other PMR variety, Merlin, was found to be very susceptible to bacterial wilt. A range in susceptibility was also detected among PMR muskmelons. Both race 1 and 2, but not race 3, were present based on powdery mildew occurrence on differential genotypes. Some PMR muskmelons with resistance to both race 1 and 2 (Starfire and HMX 7607) had significantly less powdery mildew than PMR muskmelons with resistance only to race 1 (Eclipse and HMX 7606). Apollo, which has resistance to both races, had a similar amount of mildew as Eclipse. Applying fungicides to Eclipse and to Apollo improved control. The 7-day program was more effective than the 14-day program when compared using Eclipse. Other diseases, which are controlled by fungicides used for powdery mildew, can become a problem when resistant varieties are used alone to control powdery mildew. Anthracnose was a much greater problem in nontreated than fungicide-treated plots in the muskmelon experiment. Also, PMR varieties may be more susceptible to other diseases than other varieties. PMR pumpkin Merlin had a higher incidence of bacterial wilt than susceptible pumpkin Harvest Moon (90% vs 3% on 25 Aug) in another IPM-funded project. It was not possible to investigate the possibility that PMR pumpkins and squashes, like PMR muskmelons, respond differentially to the races of the powdery mildew fungus. Phytophthora blight developed in this research field

Evaluation of Harpin for the Control of Insect-Vectored Bacterial Wilt of Pumpkin and Comparison of Cucurbit Crop Types and Cultivars for their Attractiveness to Cucumber Beetles and Susceptibility to Bacterial Wilt

ReportRecently there has been a dramatic increase in the occurrence of bacterial wilt, especially in pumpkin and squash, not only in New York, but also elsewhere in the U.S. The bacterium causing this disease (Erwinia tracheiphila) cannot be controlled directly with pesticides, therefore, management practices have targeted the insects that harbor and vector the pathogen, which are the striped and spotted cucumber beetles. Application of insecticides is the main management practice being used. The goals of this project, which was started in 1999, were 1) to determine if harpin can reduce beetle infestations and/or the occurrence of wilt and 2) to compare cucurbit crop types and cultivars for their attractiveness to cucumber beetles and susceptibility to wilt. Unfortunately, harpin does not appear to an effective tool for managing beetles or wilt in a highly wilt-susceptible pumpkin cultivar. It may be effective with other cucurbit crops

Further Additions to the Vegetable MD Online Web Page on Identifying and Managing Diseases of Vegetable Crops in New York

ReportVegetable MD Online web page was expanded during 2001 to serve as a valuable resource for the identification and management of diseases of vegetable crops occurring in New York and in the Northeast. The site has received attention by extension specialists, growers, and homeowners in New York and literally throughout the world. Numerous requests were received to use material and photographs used throughout the site. The site has added over 100 new images, has been listed by several web search engines, and has been added to several University sites as a major resource

Evaluation of Composts for Managing Phytophthora capsici

The goal of this long-term project is to evaluate commercially available composts for managing Phytophthora capsici on vegetables. This disease is very persistent in soils, and causes severe losses of both plants and harvestable fruit, under warm, moist conditions. Fungicides have only been moderately successful at providing control. A combination of good cultural practices and enhancing soil quality and disease suppressiveness is one strategy for management. In this project, we are trying to reduce the levels of disease in a research field that has a long history of Phytophthora

Evaluating New Nozzles and an Air Assist Sprayer for Improving Spray Coverage and Powdery Mildew Control on Underleaf Surfaces

ReportThe goals of this project were to identify equipment that maximizes spray coverage on the underside of leaves of cucurbits and to determine if powdery mildew can be controlled effectively with nonsystemic fungicides when coverage is maximized. Conventional nozzles and sprayers deliver little spray material to the underside of leaves. Therefore, growers presently rely on systemic fungicides to control powdery mildew in cucurbits. Fungicide resistance is a major concern because systemic fungicides are at risk for resistance development due to their single-site mode of action and because the powdery mildew fungus has demonstrated high potential for developing resistance. For this project, unfortunately, it was only possible to examine spray coverage because of technical problems with the sprayer. Greater coverage on both leaf surfaces was achieved with the air induction and twin jet nozzles, two novel types for a conventional hydraulic spray boom, than with the traditional flat fan, hollow cone, and cone jet nozzles. Better coverage was obtained on upper leaf surfaces with these novel nozzles than with the air assist boom; similar coverage was obtained on the underside of leaves. The differences between the novel and traditional nozzle types were not great, however, this was a limited study because it could not be started until late in the growing season. Additional research is needed to further these preliminary results and to obtain a true measure of spray coverage by examining disease control