The wet weather in many parts of southern Illinois has certainly been good for grass growth. But wet, humid weather is also good for plant diseases. As a result, some plant diseases are quite common this year.

Anyone who has not been regularly treating their apple tree probably has numerous rust and scab lesions on the leaves. The same is true for peach leaf curl infections on untreated peach trees as well as leaf spots on strawberries. While a few lesions on an occasional leaf is not a big deal, infections on numerous leaves will cause premature defoliation and a reduced crop.

Wet weather diseases are common on many plant species. Examples include powdery mildew on many plants; tip dieback (diplodia) on pine trees; black spot on roses; leaf spots on many plants (flowers, trees, strawberries, tomatoes, etc.); and anthracnose leaf disease on many plants.

In some cases, these diseases will not harm plant growth; but, severe infections can cause irreparable damage. The level of damage depends upon many factors—including the age of the plant, the plant's overall health, the infection level, and the severity of disease.

If the problem is severe, treatment may be necessary. But, remember that an accurate diagnosis is key. If you need help diagnosing a problem for a client, your local Extension office can connect you with an educator or specialist for assistance.

Also, remind clients that they need to help plants remain as healthy as possible. Improving air circulation, mulching, and providing nutrients will go a long way toward keeping plants healthy. And, of course, planting disease-resistant varieties is always a good idea.

University of Illinois Extension is offering two informative tours in the region this month. Spread the word to interested clients . . .

Organic Farming
Friday, June 12
12:30 – 4 p.m.
Farmer Browns Produce, Pomona
Clear Creek Farm, Cobden

The focus of this tour is on organic food production and choosing whether to certify. You'll see a
diversified organic operation and niches such as garlic varieties valued by area chefs. You'll also learn about the community supported agriculture model of direct marketing.

Cost for the tour is $10 per person. For registration and details, visit http://asap.sustainability.uiuc.edu/ and click on Organics in the topics column, or contact Dan Anderson at 217-333-1588.

Growing Strawberries Naturally
Friday, June 19
9 a.m. – 1 p.m.
Jed's Farm, Thompsonville

Judy and Ernie Duckworth will showcase their way of growing strawberries, which includes fewer chemicals and a longer growing season. They use black plastic with compost that is made from the manure in their cow/calf operation, rather than the methyl bromide that many other fruit growers use.

Only three acres of the 80-acre farm are devoted to a fruit and vegetable operation. But, the Duckworths say that the strawberries are more lucrative than their cows.

During the lunch that follows the tour, John Pike, U of I Extension community and economic development educator, will discuss marketing specialty crops.

Advance registration by June 12 is needed. The fee is $20, which includes lunch. You can register online or by phone:

For credit card payment, visit http://web.extension.uiuc.edu/smallfarm/ag_tours.cfm.

To pay by cash or check, call the Franklin County Extension Office, 618-439-3178.

Bagworms feed on the leaves of evergreens such as white pine, blue spruce, and red cedar. They can also be found on cypress and other deciduous trees.

As bagworm caterpillars mature, they hang like ornaments. Damage is most severe on evergreens, where leaf loss can cause branch death. The trouble is often we don't notice the bags and the damage until late in the season when hand picking the bags is the only option.

The female produces 500 to 1,000 eggs in one bag, which can result in large populations on a single plant.

The bag is made of silk and bits of twigs and leaves of the host plant. Active bags will have green leaves or needles on the top. The bag enlarges as the caterpillar grows.

In southern Illinois, bagworm egg hatch occurs in June. Pesticides are most effective if applied two weeks after egg hatch. Control should begin in mid-June. An additional application is advised one to two weeks later to control caterpillars that emerge later.

U of I Extension suggests these options for bagworm control: Bacillus thuringiensis kurstaki (sold as Dipel or Thuricide), and insecticides with cyfluthin.

Insecticide sprays are effective against the young larvae, but bags that are 3/4 inch long or longer are difficult to control. The bacterium Bacillus thuringiensis is effective on young caterpillars, but the material must be ingested—so thorough plant coverage is essential.

Cyfluthrin is recommended for larger larvae, but again, thorough coverage is necessary.

If you've seen a purple contraption that resembles a box kite hanging from a tree, it's likely an Emerald Ash Bore (EAB) trap. The Illinois Department of Agriculture has placed approximately 5,000 EAB traps throughout the state.

The traps primarily are concentrated in a 50-mile buffer zone that runs along the state's western border from northern to central Illinois and then cuts a swath across the south-central part of the state to the Indiana border in southeast Illinois. The Ag Department asks that these traps be left alone.

EAB is an invasive beetle that has devastated tens of thousands of ash trees in Illinois since it was first discovered in the state in 2006.

The Emerald Ash Borer is a small metallic-green insect, about one-third to one-half the size of a penny. Adults can fly but not for long distances. The borer will tunnel under the bark and start feeding on the sapwood of the tree, causing leaves to thin and yellow.

Besides the color, D-shaped holes on the bark are another clue. No other insect creates the BB-size, D-shaped holes on ashes. Also, trees may produce shoots around the trunk at ground level.

There are other metallic-green insects, including many beetles, which can make identification of EAB more difficult. The false June bug is a common metallic-green beetle, though it is almost the size of a quarter. Japanese beetles are metallic green as well, but with a coppery overtone.

Compounding the problem, ashes are plagued by other insects including another ash borer and sapsuckers, all of which can cause holes in the trunk of the tree and lead to a decline in the overall health of the tree, including the yellowing and thinning of the leaves. Homeowners need to look carefully to determine the cause.

Sapsuckers (a type of woodpecker) create uniform rows of round holes up and down the tree's trunk. The sapsucker is a protected migratory bird, so control is limited.

Lilac/Ash Borer is a moth that looks almost wasp-like. The caterpillar tunnels beneath the bark on both lilacs and ashes. Females lay eggs on the bark, and the larvae tunnel beneath and start feeding during late May and early June. The presence of fine sawdust material called frass is an indication of tunneling. The holes made by this insect are round instead of D-shaped.

Several diseases and environmental factors can also create problems. Anthracnose, a common spring fungal disease, causes leaves to become twisted, water-soaked, and turn olive-green; then, the leaves fall off. Usually, the tree will produce more leaves, so the long-term effect is minimal.

Ash Decline is a name for a group of symptoms. The term is used to describe the overall decline of the tree, starting with dieback of branches and limited new growth. Leaves may be sparse, giving the tree a sickly appearance. Trees generally don't die abruptly. Instead, they may decline over five to 10 years. Trees seldom produce any shoots at ground level next to the trunk.

Horticulturists and plant pathologists haven't been able to isolate a causal agent, though some suspect a microorganism. Ash Decline could also be confused with the effects of Ash Yellows or fungal Verticillium Wilt.

A multi-step approach is needed to protect ash trees:

· Maintain the health and vigor of ash trees. Like most plants, trees under stress are more likely to be infested by insects or infected with diseases. Water during droughts and maintain proper nutrient levels. Mulch the tree out to the drip line to avoid mower injury and grass competition.

· Avoid planting ash trees. While ashes are fast-growing, strong wood shade trees, they suffer several problems. If the Emerald Ash Borer moves further through the state, expect damage to occur. Work with your local nursery or garden center on alternatives to ash trees.

· Be vigilant. Look for D-shaped holes and the small emerald-green adult borer. Check trees regularly, particularly in the spring and early summer.

· Be open-minded. Remember, not every problem with the ash tree is caused by the EAB. It's wise to be concerned, but don't get to the point of crying wolf.

· If you do suspect Emerald Ash Borers, contact your local U of I Extension office.

To learn more, log on to SI Gardening, http://web.extension.uiuc.edu/regions/hort and click Pests and Diseases.

You're at a local farmer's market eyeing a bushel of vegetables or fruits, and you start to wonder if it truly is a bushel.

A bushel of produce is a bushel when it meets the legal standard of volume of dry measurement containing four pecks, 32 quarts, or 2,150.42 cubic inches. Anything less than this volume is not a bushel, and consumers should be aware of small containers or amounts advertised as bushels.

In other words, a bushel is an amount based on volume and not weight. It's what the box or basket will hold rather than how much it weighs—a big difference!

Years ago, laws included legal weights for bushels of commodities. As varieties and grade sizes changed, so did the density and weight of the produce. Many of the legal weights became outdated. Today produce may be sold by volume in open containers and net weight in closed containers.

The bushel container is a carryover from days of yesteryear, when the bushel was a convenient volume of packing and use. Now it is less common because of the demand for smaller containers and improved quality control. But, many farm markets, roadside stands, and terminal markets still sell by the bushel— using baskets, boxes, and hampers.

In Illinois, commonly accepted weights in pounds per bushel for fruits and vegetables are as follows: apples, 42–48; grapes, 44–50; peaches, 48–52; pears, 48–50; green beans, 28–30; cucumbers, 4–50; greens, 18–20; and tomatoes, 50–60. Consumers buying by the pound can convert to bushel prices by using these weights.

Other common produce containers for volume sales are pecks, quarts, and pints. Most of the pecks of fruit should weigh 10 to 12 pounds, whereas pecks of vegetables are quite variable due to differences in texture and weight of the crop. Quarts of small fruits such as strawberries, raspberries, and blueberries weigh 1.4 to 1.5 pounds