National Elm Trial

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

On-farm Cooperator Trials: Effect of Extended-duration Row Covers on Muskmelon and Winter Squash on Bacterial Wilt and Yield

Susceptible cucurbit crops are difficult to grow in Iowa because of bacterial wilt, caused by Erwinia tracheiphila. Striped and spotted cucumber beetles transmit bacterial wilt. Other insect pests such assquash vine borer and squash bugs may also have an economic impact on yield, particularly in squash

Evaluating the Impact of Spray Volume and Pruning on Effectiveness of the Sooty Blotch/flyspeck Warning System

A sooty blotch flyspeck (SBFS) warning system, developed in North Carolina and modified in Kentucky, extends the period between first-cover and second-cover fungicide sprays until a total of 175 hours of wetness has been measured in the orchard canopy. After the second cover, sprays are made at 2-week intervals until harvest

National Elm Trial for Iowa

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

National Elm Trial Update for Iowa, 2007

The graceful American elm that once dominated urban forests across the United States has essentially disappeared from urban landscapes after the introduction of Dutch elm disease. This tragedy illustrates why it is essential to maximize genetic diversity within the nation’s urban forests. Exotic pathogens and insects continue to threaten the health of our shade trees. Dutch elm disease-resistant elm cultivars could enhance the diversity as well as the beauty of urban forests. Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

Controlling Bacterial Wilt in Muskmelon with Perimeter Trap Cropping

Perimeter trap cropping (PTC) involves planting one or more rows of a cucurbit crop that is highly attractive to cucumber beetles around the border of a main cucurbit cash crop that is less attractive to the beetles. Cucumber beetles attempting to migrate into the field are concentrated in the relatively more attractive border crop, where they can be controlled by insecticides

Organic Practices for the Production of Muskmelon

Cucurbit crops, especially muskmelon and cucumber, attract cucumber beetles, which vector Erwinia tracheiphila, the causal agent of bacterial wilt. High numbers of overwintering beetles, which often lead to high bacterial wilt incidence, usually occur during the first stages of plant establishment. Growers of organic muskmelon need effective ways to manage the cucumber beetle/bacterial wilt complex, particularly during the highestrisk period early in the season

Organic Practices for the Production of Butternut Squash

Growers of organic squash need effective ways to manage insect and disease problems. The squash bug (Anasa tristis) sucks sap, causing leaves to wilt and turn black. The squash vine borer (Melittia cucurbitae) can devastate winter squash plantings. Burrowing by larvae into the base of the stem causes yellowing and wilting. Organic insecticides are expensive, have limited efficacy, require many applications, and some kill beneficial as well as target insects

Koch’s Postulatesfor New Species of Sooty Blotch and Flyspeck

Sooty blotch and flyspeck fungi(SBFS) infect the cuticles of the apples resulting in dark blemishes on the surface. The number of species identified in the SBFS has increased with the help of molecular techniques. The following report summarizes the progress of confirming the identity of additional SBFS species using a modified Koch’s postulates. Molecular techniques of DNA extraction and amplification were applied to fungi isolated from signs on apples