Henderson Co. Agriview: "Leaves of three, let it be!"
by Rick Hirsch

Regardless of the plant, follow the old adage - "leaves of three, let it be!"

Poison oak usually does not climb as a vine, but occurs as a low growing shrub. Stems generally grow upright. The shrubs have rather slender branches, often covered with a fine pubescence that gives the plant a kind of downy appearance. Leaflets occur in threes, as in other ivy, but are lobed, somewhat as the leaves of some kinds of oak. The middle leaflet usually is lobed alike on both margins and resembles a small oak leaf, while the two lateral leaflets are often irregularly lobed. The lighter color on the under side of one of the leaves is caused by the pubescence, or fine hairs, on the surface. The range in size of leaves varies considerably, even on the same plant.

Many people know through experience that they are susceptible to poisoning by poison ivy, poison oak or poison sumac. Others, however, either have escaped contamination or have a certain degree of immunity. The extent of immunity appears to be only relative. In repeated contact with the plants, persons who have shown a degree of immunity may develop poisoning.

The skin irritant of poison ivy, poison oak and poison sumac is a non-volatile phenolic substance called urushiol, found in all parts of the plant. The danger of poisoning is greatest in spring and summer and least in late fall and winter.

Poisoning usually is caused by contact with some part of the bruised plant, as actual contact with the poison is necessary to produce dermatitis. A very small amount of the poisonous substance can produce severe inflammation of the skin. The poison is easily transferred from one object to another.

Clothing may become contaminated and is often a source of prolonged infection. Dogs and cats frequently contact the plants and carry the poison to children or other unsuspecting persons. The poison may remain on the fur of the animals for a considerable period after they have walked or run through poison ivy plants.

Children who have eaten the fruit have been poisoned although the fruit when fully ripe is reported as nonpoisonous. A local belief that eating a few leaves of the plant will develop immunity in the individual is unfounded. Never taste or eat any part of the plant.

HORTICULTURE FIELD DAY:

On June 28th, nursery growers, greenhouse managers and gardening enthusiasts can view field tests of flowering bedding plant varieties at the annual Overton Horticultural Field Day.

There are over 800 varieties this year and that includes 180 varieties in the container trials.

The field day will begin at 8:30 a.m. at the Texas A&M University System's Agricultural and Research Center's North Farm site. The tour will continue at the North Farm site until about 10:30 a.m., then move to the Overton Center's headquarters building where a demonstration garden is located. Lunch will be served at about 11:30 a.m.

Trials of bedding plants at the Overton center serve the commercial greenhouse and bedding plant industry. In recent years, the industry has had a $500 million annual economic impact on the region, according to the Texas Agricultural Statistics Service.

Since the first field day with less than 100 varieties, the event has grown to include vinca, ornamental peppers, trailing petunias, verbenas, begonias, portulaca, zinnias, geraniums and ageratum. This year, there will be an emphasis on impatiens, including regular impatiens, New Guinea varieties and some miniature types.

The field performance trials are now replicated at the Texas A&M University Dallas Center and the trial results are coordinated with the Dallas Arboretum. Over 5 million consumers now have the opportunity to see how promising new plants from all over the world perform in our climate.

Though begun primarily to serve the bedding plant industry, with the trial's thousands of square feet of plots planted in purple, pink, red and white flowers, they have become popular with regional gardeners. Because it is such a colorful event, Texas Highways magazine featured the field day in its March 2007 issue.

Registration is free and will include a lunch. The Overton center is located 1 mile north of downtown Overton on State Highway 3053.

The North Farm site is about 4 miles north of the center on State Highway 3053. For an online map, go to http:/ /overton.tamu.edu/flowers/ fieldday.htm.

CORN PRICES ON THE RISE:

In its May agricultural prices report, USDA offered no summary explanation for a 60 percent jump in corn prices over the same period a year ago. It seemingly goes without saying.

Confirming expectations, the price of corn continues to rise alongside swelling demand for ethanol. May's price for corn was $3.48 per bushel, a 9-cent increase from April alone. In May last year, corn cost only $2.17.

Kevin Barnes, chief of USDA's Environmental, Economics and Demographics branch, points out that the report reflects mid-month prices, and that prices tend to fluctuate through the end of the month. Whether prices will stabilize is harder to predict, he told Meatingplace.com.

In April, USDA released a report indicating that farmers intended to plant 90.5 million acres of corn this spring, the largest such sowing in 63 years. Experts predicted that volume would translate into 12.5 million bushels of corn.

Soaring corn prices also are pushing up prices for other commodities, as farmers devote fewer acres to crops like soybeans. As of mid-May, the price for soybeans was $7.15 per bushel, up from $6.88 in April and nearly 26 percent higher than the May 2006 price of $5.58.

USDA reported that the average price for all crops in May was 3 percent higher than April and 24 percent higher than the same period a year ago.

IMPORTANT DATES:

June 18 & 19 - District 5, 4-H Horse Show, Henderson County Fair Park Complex

June 28 - Horticultural Field Day, 8:30 a.m., Overton

Rick Hirsch is the Henderson County Extension Agent-Agriculture for Texas Cooperative Extension. Visit his web page at http:// henderson-co.tamu.edu.