Extension Notes: Apple pests can be controlled with bags
Spraying fruit trees is a regular chore for anyone trying to produce edible fruit here in our area of the country. In many cases we’re trying to prevent adult insects from laying eggs on or near apples or other fruit and therefore keep the babies or larvae from boring into and damaging the fruit. Chemical sprays are often our only choice. However there is an alternative that has captured the attention of some Kentucky researchers.
University of Kentucky researchers have found that some apple defects can be reduced by bagging the fruit as it grows. Home fruit growers who have been discouraged by wormy, deformed or unsightly apples may want to try the technique.
Fruit problems reduced by bagging included sooty blotch and flyspeck, which are dark smudges and black specks caused by fungi. Other fruit problems reduced included codling moth worms and cork spot, a dark depression with corky tissue underneath it.
The bags reduce these problems by physically blocking access to the fruit by the pests. But scientists are puzzled by the reduction in cork spot, which is caused by a calcium deficiency, not by a pest. To bag apples, buy some 3-pound, white-paper, grocery bags. The bags must be white to allow some light to enter and color the fruit. Don’t use plastic bags. They’ll become too hot inside. Place a bag over an apple when it’s about 1 inch in diameter, and secure it with a twist-tie. Leave the bags on the fruit until harvest. For late-maturing varieties, the researchers found you can remove the bags in late August, with no harm done afterwards by pests. Removal of bags at this time can enhance fruit coloration.
Bagging won’t control early-season pests such as scab, rust, plum curculio or catfacing insects. Bagging may take some time, but certainly no more than a spray program would. Soil Acidity Can Affect Your Lawn
So what if your lawn’s soil is acidic? Here’s the “so what.” Acidic soil influences the uptake of mineral nutrients by lawn grasses.. Lawn grasses growing in strongly acid soils may be low or deficient in phosphorus, calcium, magnesium or molybdenum. The micronutrients boron, copper, iron, manganese and zinc are less available for lawn grasses in alkaline soils. Overall nutrient availability is highest in slightly acid soils.
Lawn grasses growing in strongly acid soils are often poorly rooted and slow-growing. Roots may be shallow, sparse and brown. Aluminum, soluble under strongly acid soil conditions, can reach toxic concentrations.
Soil acidity influences the activity of microorganisms that decompose organic matter. Excessive thatch may quickly develop in lawn grasses maintained in strongly acid soils. Bacteria, the smallest and most numerous microorganisms in soils, are most active at pH 6-8, fungi at pH 4-8 and actinomycetes at pH 7-7.5. (Pure water has a pH of 7.0.)
Earthworm activity is reduced as soils become more acidic. As earthworms channel, they mix plant residues with soil and improve the movement of air and water in soils.
Lawn grasses growing in soils with near neutral pH are reported to be less susceptible to certain fungal diseases, including red thread, Rhizoctonia brown patch and Pythium.
Simple “home test” kits, including those that use a reagent to develop a color in liquid, are available for determining the soil’s acidity. But how much lime would it take to neutralize soil acidity and raise the pH?
A test conducted in a qualified soil-testing laboratory is the most reliable way to determine the need for lime. For example, at some pH levels soils high in clay or organic matter require more lime to neutralize soil acidity than light, sandy soils.
Give us a call here at the Extension office for more information on soil testing. It’ll pay big dividends for your lawn.
CARPENTER BEES SEEN PATROLLING STRUCTURES
Carpenter bees have been very active this last week or so and residents have been alarmed by these large bees flying near eaves. Quite often it is the male carpenter bee that is seen patrolling the area and they are unable to sting. The females are not aggressive, but may bite and sting if handled. Males are easily distinguished from females by their white marking on their “face. Carpenter bees are large bees and are similar in appearance to bumble bees, except the dorsal (top) surface of the abdomen is almost devoid of hairs and appears to be entirely black in the carpenter bee. Also, don’t confuse the white-faced male carpenter bee with a bald-faced hornet which also has a white face. You’re most likely to encounter a female bald-faced hornet, and she is not forgiving.
Carpenter bees bore an oval shaped tunnel opening into their wood target. The tunnel goes straight from the opening, but soon makes a right angle turn to go with the grain of the wood. In the gallery the female lays an egg, provisions it with nectar and pollen and seals the cell with chewed wood pulp. Galleries may contain six cells and are four to six inches long on average. However, because the galleries are reused and may be used by more than one bee, lengths of up to 10 feet have been reported. The new adults will appear in late summer.
Nonchemical or preventive controls include painting or varnishing wood surfaces. Individual bees can be caught with a net and killed or swatted with a badminton racket. Also, a flexible wire can be inserted into the hole to kill adult and larval bees, but the wire needs to be strong enough to break the wooden cells and flexible enough to make the right angle turn.
Insecticidal dusts can be puffed into nest holes in the evening when the carpenter bees are at rest. Insecticidal dust fills the void very well and will not soak into the wood as a liquid might. The bees should have access to the nest for 24 hours to allow them to spread the dust through the galleries. Then seal the hole with putty, dowel or cork to prevent re-infestation.. Carpenter bees overwinter in previously used galleries, so the structure should also be inspected in the fall and any holes that may have formed should be treated and sealed. We’ve got a fact sheet on Carpenter Bees available here at the Extension office.