Evaluation of Hosta Cultivarsfor Resistance to Petiole Rot

Petiole rot of hosta, caused by the soilborne fungi Sclerotium rolfsii and S. rolfsii var. delphinii, appeared first in the southern United States. The rapid spread of petiole rot in the Midwest U.S. during the past decade has caused increasing concern among wholesale producers, retailers, and buyers

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

Floral Provisioning for Wild Bee Pollinators in Winter Squash and Muskmelon

When we talk about pollination, the image that comes to mind most frequently is the honeybee. Honeybees do provide the majority of pollination services in our current agricultural system. However, there are wild bees pollinating flowering crops at the same time and these bees are capable of providing a significant portion of the pollination services required of many crops. In fact, in some instances, wild bees may be better pollinators than managed honeybees

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

Trapping and Other Strategies for Control of Cucumber Beetle in Muskmelon

Spotted and striped cucumber beetles (Diabrotica undecimpunctata howardi and Acalymma vittata) that vector a bacteria that causes bacterial wilt in cucurbits are the major pest in Iowa muskmelon fields. Growers currently spray insecticides to control these insects on a one- to two-week preventive schedule. Use of large amounts of chemical can be expensive and damaging to beneficial pollinators and the environment. We investigated the success of the prototype Trece trap-and-bait system—soon to be Organic Materials Review Institute approved— in controlling these beetles. The traps chemically lure beetles to insecticide-treated baits inside the traps, placed some distance away from the muskmelon crop. We also tested three other management methods in combination with the traps: Reemay® row covers, slitted row covers, and transplants treated with BioYield® (rhizobacterial) potting soil

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