About Me

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As an Agriculture Extension Agent for Texas AgriLife Extension Service I have had an opportunity to be involved in just about every aspect of agriculture. From the 5,000 cow dairy to the types of trees to use in a home landscape I have had a chance to learn how the different parts of an agriculture systems work together. Seedless watermelons, drip irrigation, pecan orchard management, fruit crop development, dairy nutrient management, environmental issues confronting agriculture, producer tours, field days, research projects and more have been a part of my life for over 30 years as I lived and breathed agriculture. Since 2004 I have been actively involved in consulting internationally working in Honduras, Guatemala, Egypt, Jordan, Iraq, India, and China. I have worked with missionaries and other groups dedicated to alleviating poverty among third world farmers. I lived in the Middle East in 2007-2008 working on a project for the Borlaug Institute of International Agriculture at Texas A&M University. In this project I was the Chief of Party and Team Leader for a $5.7 Million dollar effort to train Iraqi Extension agents and specialists in all aspects of agriculture.

Monday, April 6, 2009

Fruit Tree Insect and Diseases

I think we can blame the drought for causing another problem, terrible insect pressure especially on our fruit trees. Most if not all fruit trees have made it through the winter, and most have survived the drought, if you watered. They have made it through freezes and most have small fruit, no small miracle for Texas fruit production! Now after making it through all these problems we have one more to add to the list, stink bugs!
Both the brown stink bug and the green stink bug overwinter in grassy areas and under brush or wood. They wait for warm weather to come out and begin looking for energy sources to replace lost body reserves and the plant of choice is fruit. The brown stink bug causes the fruit to deform and the green stink bug causes the fruit to exude a resin or gummy mess that can accumulate on the fruit especially on peaches. Both insects have long snouts that they use to pierce the skin and suck out juices. In the case of the green stink bug this resin attracts wasps and bees so that they get the blame instead of the stink bug. Stink bugs are hard to control especially since they have piercing/sucking mouthparts. Carbaryl or permethrins are two of the most effective inorganic chemicals but for organic growers your only choice is neem oil and its effectiveness is not good
There is one major peach insect that everyone wants to get rid of, the Plum Curculio. This small worm or grub feeds inside the peach mostly near the seed and can cause anyone who has found one a real heartache. This worm or larva is laid by an adult snout beetle, similar in looks to the oak, pecan or cotton weevil. This adult overwinters in the soil at the base of the fruit tree and comes out early with the plums and moves to peaches as plums mature early. The adult female will chew a small hole in the fruit skin and lay eggs just under the surface. The eggs hatch into small larva that feed in the fruit for 2 to 4 weeks and of course this is what causes the problems.
To control this insect sprays have to be made from shucksplit (about the time the fruit is formed) and for two applications at two week intervals and then 30 days before fruit harvest. This last spray is probably the most important since the eggs laid hatch out and the larva are still in the fruit at harvest. Recommended sprays are malathion, carbaryl or permethrin and organic is garlic and citrus oil, and neem oil to repel the adults. There is no insecticide to treat the soil with but keeping old fruit off the ground helps prevent next year’s problems.
Another problem some homeowners have complained about is the gummy mess coming out of fruit tree limbs. This gum or resin is caused by a bacterial canker that has infected the limb. This canker develops in the fall and as the trees break dormancy in the spring, gum is formed by the infection and can break through the bark and flow down the tree limb. Stress in trees is the main culprit and treatments are not effective. Keep damaged wood trimmed out and supply water and nutrients to promote tree health.

1 comment:

Anonymous said...

I sprayed my treeswith zinc and notice 5he leaves with black spots and leaves shrink. Help!!! Worried.