Lexington, Kentucky 40546
      
Nursery Update - A University of Kentucky Cooperative Extension Service update for the Kentucky Nursery Industry
    
By Amy Fulcher, Extension Associate - Nursery Crops
University of Kentucky Department of Horticulture
Update #27
September 21, 2004

Insect
 Eriopheyes pyri is an eriophyid mite that overwinters under bud scales of callery pears. In the spring, mites begin feeding on the undersides of leaves. Mites then lay eggs in the damaged leaf. On the upper leaf surface a pimple-like swelling develops into a blister. These blisters run together and form large brownish areas.

Serious injury was common in the 1800's and early 1900's and may be a problem again as more pesticides become pest-specific meaning sprays applied for other pests will not also control this pest. Eriophyid mites are small, hindering scouting.
Source: Insects that Feed on Trees and Shrubs. Cornell University Press.
 

Broad Mites
Polyhagotarsonemus latus can be a pest of nursery crops when the plants are overwintered in greenhouses. Leaves curl downward and turn purplish. Internodes shorten and many lateral buds break. This new growth may also be stunted or killed, which forces additional shoots. Flowers are distorted. Broad mites attack many plants. They are small; scout carefully with a 15-20x hand lens.

Talstar, Scimitar, and Sanmite are all labeled for control of broad mite. Talstar is a contact pesticide, so it is important to cover thoroughly all plant parts. Talstar provides between 7 and 21 days of residual activity. Scimitar is a contact and stomach poison (when ingested) providing up to 14 days of residual activity. Scimitar and Talstar have the same mode of action, so avoid using these two products in succession. Sanmite is a contact miticide so thorough coverage of all plant parts is important. Sanmite has activity on all mite life stages, including eggs. Sanmite is fast-acting on the mobile stages and provides up to 45 days of residual activity. The predatory mite Neoseiulus barkeri has successfully controlled broad mite on edible crops in greenhouses at the EPCOT Center.

Source: Fan, Y. and F. L. Petitt. 1994. University of Illinois Extension; Texas Coop. Ext. Service; Biological control of broad mite, Polyphagotarsonemus latus (Banks), by Neoseiulus barkeri Hughes on pepper. Biological Control 4: 390-395.

Left: Inkberry holly infested with broad mites, grown in shaded house.

 Right: Inkberry holly infested with broad mites, grown in sun.

Pruning Container liners
Recently planted container liners can be staked and lightly pruned to get a good start on developing a desirable shape. Some growers use a section of bamboo to measure the length of trunk that should be pruned free of branches. This guide eliminates any guesswork, which allows the employees to move faster through the field and make fewer mistakes.

 
 

Training Leaders in Container Liners

The central leaders on liners planted this fall may need some pruning and training in order for them to get off to a good start next season and to prevent injury during unfavorable weather.

Tape on far side of trunk is used to pull trunk in to the stake.

Wrap masking tape 2-4 times.
Finished leader.
      

Phenology Fact: Spruce spider mites are active again. Scout spruce (especially Alberta spruce), pine, juniper, fir, arborvitae, hemlock, taxus and false cypress. The mites are green to deep olive to brownish red in color. Close inspection of the needles will reveal tiny white flecks where the mites have fed. Ovewintering eggs are laid from Sept.- November. See Spider Mites on Landscape Plants for recently updated control options.

 

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