Sawflies
Sawflies are small insects that can cause great damage to ornamental plants. Sawflies resemble caterpillars. Caterpillars have 2-5 pairs of prolegs (fleshy leg-like growths), sawflies have more than 5 pairs. The difference is important when considering control options. Bt products are not effective on sawflies.

Birch trees and pines are much more likely to suffer from sawflies than the callery pear shown in this image. Two clusters per tree is the action threshold for pine sawflies on pine. This threshold could be modified for other sawflies. The one cluster found on this plant doesn't warrant the cost and labor to spray. A cheaper and faster solution when few sawflies are found is to remove and destroy by hand.

Source: Developing an Integrated Pest Management Program for Nurseries Purdue Pub. E-213, Buckeye Yard and Garden Line 2003-13. Pine Sawflies. U.K. Entfact 410.

Irrigation
As warm days continue it is important to check irrigation emitters, daily is not too often. Emitters become plugged and need to be cleaned or replaced. Rodents chew on tubing. The emitter can be dislodged by foot traffic or by equipment catching on the tubing.

As plants grow their water use increases, yet an increasing trunk or stem size can block water (see photo). In addition, the second season in production for pot-in-pot plants may mean roots and decomposing substrate are reducing the pore space available to hold water.

Use of Cyclic Irrigation in PNP Production
Cyclic irrigation scheduling, dividing the daily water allocation into multiple applications, can save water and fertilizer and increase plant growth. Cyclic scheduled, micro-irrigation has been found to reduce water consumption during production of live oaks by 1/4 to 1/16 of that applied in overhead irrigation. Cyclic irrigation reduces nutrient leaching by as much as 41% and irrigation runoff by 30%. Red Sunset® maple grown in a pot-in-pot system with cyclic irrigation 3 or 6 times a day had approximately 20% more shoot growth, 25% greater caliper, and 16% greater height than those grown with a single irrigation application.

Birch Exudate
Some birches exude a resin from the stems called papyriferic acid. In appearance it can resemble a scale infestation. Some have linked the tendency to produce this exudate with a plant population evolving under heavy feeding pressure from mammals. The photo at right shows probable resin exudate on Betula papyrifera Renaissance Reflection™.

A bibliography of birch articles can be found at:
http://www.atkinsonm.demon.co.uk/birchbib/bibr.htm

Announcement

The KNLA Summer Outing will be held September 4, 2003 at the University of Kentucky Arboretum. Dan Heims is the featured speaker. Dan is the president of Terra Nova Nursery, Canby, Oregon. He will be speaking on New Perennials and New Plants from Around the World. Dan will repeat his presentation after lunch so that everyone has a chance to hear him and enjoy the pigroast, tour the arboretum, and see vendor exhibits. Commissioner of Agriculture candidates are invited to attend.

Cost to attend $25 per person (bring 4 people and the 5th person is free). Registration begins at 8:30am Eastern time and activities conclude at 4:30pm.

Booths are still available for vendors, $175 per booth. Platinum ($250), gold ($150) and silver ($100) sponsorship opportunties exist.

Contact KNLA Executive Director, Betsie Taylor, at (502) 848-0055, (800) 735-9791, or by email at knla@mis.net.