September 16, 1994

Harvesting, Cracking, and Storing Black Walnuts

The black walnut (Juglans nigra) is one of the most valuable  timber trees in Iowa. It is also a valuable nut tree.

Captan Label Changes for Strawberries

The fungicide Captan has long been a mainstay of disease-control programs for growers of apples, small fruits, and berries. Sevral years ago, EPA put Captan went through its Special Reviewprocess to better assess its health risks as well as its benefits. Captan emerged from Special Review with a new restriction on itslabel: a 4-day reentry interval. The reentry interval meant thatworkers could no reenter a Captan-sprayed field for 4 days unlessthey wore protective clothing (long-sleeved shirt, long pants, andnonabsorbent boots and gloves).

EPA Report on U.S. Pesticide Use

A new report released by the EPA indicates that pesticide usein the U.S. equaled about 8.8 pounds per capita, relatively stableat about 2.2 billion pounds of pesticide active ingredients. Thetitle of this new report is "Pesticide Industry Sales and Usage,1992 and 1993 Market Estimates," and was assembled by EPA's ArnoldAspelin. Conventional pesticide use remained at about 1.1 billionpounds of active ingredient. Wood preservatives and disinfectants(non-conventional pesticides), pushed total U. S. pesticide use toabout 2.2 billion pounds of active ingredient.

Larger Yellow Ants Active Again

This is the time of year we begin to notice activity by one ofour most common ant species, the larger yellow ant (LYA). LYA isfound throughout Iowa and because of its prevalence next to housesis also called the "foundation ant." Normally, these ants liveoutdoors in old logs and stumps and under stones. During the latesummer and fall, however, entire colonies may move toward buildingsand try to enter through cracks or gaps in the foundation. Swarmsmay be seen either outdoors or inside the house.

Powdery Mildew on Ornamentals

The presence of a white, dusty mildew on infected plant partsmakes powdery mildew easy to diagnose. Late in the season, tinyblack fungal fruiting bodies may appear on the mildewed surface. Powdery mildew can occur on leaves, stems, buds, and flowers. Ornamental plants that commonly show signs of powdery mildewinclude lilac, viburnum, crabapple, phlox, rose, zinnia, begonia,and turf.

Powdery mildew is favored by cool nights followed by warmdays. The disease is most common in shaded areas and in siteswhere plants are crowded and air circulation is poor.

Species Tulips

Are you tired of replacing your hybrid tulips every few years? Would you like a tulip that naturalizes well? The answer lies in the selection of species tulips.

Species tulips are different than hybrid tulips. They perform best in rock garden-like locations. They require full sun,and well-drained, almost gravelly soils that drain quickly betweenrains. When preparing the site, amend the area several incheswider and deeper than the bulbs will occupy with sand or gravel. Planting on a gentle slope or in a raised bed assures gooddrainage. Plant the bulbs 5 to 8 inches deep.