No. 10/June 25, 2010
Malcolm C. Shurtleff
Malcolm C. Shurtleff, former author of this newsletter and many University of Illinois Extension publications, died on May 29, 2010 in Pearland Texas. He was almost 88 years of age at the time of death.
Japanese beetle, pine spittlebug, and magnolia scale are the subject this week.
Pythium Root Rot of Garden Plants
Root rot problems are often difficult to diagnose and can be confused with environmental stress. Above-ground root rot symptoms might include stunted growth, smaller than normal leaves, poor foliar color, dieback of stems, or sudden wilt and death of plants. Plants with Pythium root rot will have blackened root tips or soft, dark rot of the outer (cortex layer) of the roots.
Watch for Oak Wilt
As the season progresses, we see many oaks that look stressed. How do we know the cause of the stress? Some possible causes include Armillaria root rot, root compaction or injury, severe oak anthracnose, bacterial leaf scorch, and oak wilt.
Pine Wilt is the only vascular disease of pines. It is much like Verticillium wilt on deciduous trees except the pathogen is a nematode rather than a fungus. Pinewood nematode is the cause of Pine Wilt. It moves from tree to tree by way of sawyer beetles.
Transporting Invasive Species--What's hiding in your tree?
The recent storms that have swept across the state have left destruction in their wake--including downed trees and limbs. We've received numerous calls about what can be done with this green waste. Many cities have organized storm pick up or maybe even a green waste recycling center. But are you aware of the dangers associated with invasive species and moving this debris and firewood?
Saltcedar: Watch Out for This Weed!
Saltcedar (Tamarix ramosissima) is an invasive weed that poses a large threat to native ecosystems and local water tables. This plant is a native of Asia and Europe and was originally brought over in the early 1800's to be used as an ornamental and later for erosion control and wind breaks.
Aquatic Invasives: Brazilian Elodea and Hydrilla
There are two invasive species threatening America's waterways- Brazilian elodea (Egeria densa) and hydrilla (Hydrilla verticillata). Hydrilla is a persistent problem throughout North America while Brazilian elodea only survives in the north.