Insects, disease love hot, humid weather

Published 12:00 am Friday, June 6, 2014

SALISBURY — High humidity from afternoon showers creates the perfect environment for insect and disease problems. Home gardeners are experiencing both in landscape and vegetable gardens. Below are a few problems gleaned from home garden inquiries.
Question: The squash in my garden are beginning to bear but the ends of the fruit are beginning to rot. What is the problem and what can I do to help?
Answer: The problem is most likely blossom end rot, which is a common problem we often associate with tomatoes. But it also is a problem with squash and other vegetables. Blossom end rot is not a disease but a physiological disorder in the plant spurred by lack of calcium. Cool night time temperatures, low soil pH and plant stress can exacerbate this problem. Go to http://www.clemson.edu/extension/hgic/plants/vegetables/crops/hgic1321.html for more detailed information.
Question: I have a very large pecan tree and the leaves are covered with bumps. I’ve never seen anything like this on my tree. What is this? Will it hurt the tree?
Answer: The bumps you’re seeing on the leaves are insect galls. It’s caused by a minute insect, pecan phylloxera, that is similar in appearance to an aphid. The bumps will eventually turn brown and may cause some of the infested leaves to fall. The insect is more of a curiosity than a serious problem. There is no recommended control for the insect on large pecan trees. Go to http://entoplp.okstate.edu/ddd/insects/phylloxera.htm
Question: We have crepe myrtles that have new growth emerging from the base of the tree. Is now a good time to prune them out? Is there any way to keep them from coming back?
Answer: The new growth or water sprouts often referred to as suckers. These can be pruned out from around the tree now. Be sure to prune them as close to the trunk as possible and do not leave a stub. If you leave a stub, the water sprouts will quickly reappear. There are a few products on the market that claim to control the water sprouts.
Question: My tomato plants were doing well one day only to become wilted and appear to be dying the next. It does not kill all the plants, just a few. What could be causing this problem?
Answer: What you have described sounds much like southern bacterial wilt. It is a common soil-borne disease in Rowan County on tomato and pepper that kills the plant after the plant reaches a certain size. There is no adequate control for the bacteria. Try to rotate your tomato plants to another area in the garden. Go to http://www.cals.ncsu.edu/plantpath/extension/clinic/fact_sheets/index.php?do=disease&id=21 for more detailed information on this tomato disease.

Darrell Blackwelder is the county Extension director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. Learn more about Cooperative Extension events and activities by calling 704-216-8970 Facebook or online at www.rowanextension.com