Greenhouse Update - June 12, 2006
Leanne Pundt, Extension Educator, University of Connecticut
Daylily thrips – have been found feeding on Hemerocallis. Look for the small, dark brown adult thrips deep within the daylily foliage. The small larvae are light yellow in color. On fully expanded foliage, leaves become stippled. Newly emerged foliage may be distorted. Leaves, flowers or stems may have white to silver speckles. Small, dark fecal droppings can also be seen. Daylily thrips may overwinter in the pupal stage in the soil.
Thorough coverage with a fine mist is needed to contact the thrips deep within the foliage. A number of insecticides are labeled for thrips control including Conserve, Avid, and Tristar may be applied. Ornazin, Botanigard, Ultra fine oil and insecticidal soap may also be used. Repeat applications are often needed.
Powdery mildew – humid conditions have lead to powdery mildew on various crops including verbena, torenia, begonia, veronica, peony, etc. Most growers are familiar with the white, talcum powder like growth on the upper leaf surface that is characteristic of powdery mildew. Regular scouting is needed for detection because infections can begin on the lower leaf surfaces that are easily overlooked.
On some plants, infected leaves turn a purplish color. On sedum, brown scab-like lesions develop with little powdery growth. From a distance, powdery mildew could be easily confused with a leaf spot disease. Look closely for the fine, white fungal threads and chains of powdery mildew spores. See photos below.
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Powdery Mildew on Sedum |
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Leanne Pundt photos -- click for a larger image |
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3-lined potato beetles have been feeding on Chinese lanterns (Physalis alkekengi). (This is also a common pest on potatoes, tomato, tomatillo and eggplant in the home garden). Both adults and larvae chew holes in the leaves. The 3-lined potato beetle overwinters as an adult. Adults lay clusters of yellow eggs on the underside of leaves that hatch in about two weeks into larvae. See photos below.
If infestations are small, handpicking may be an option, however, adults are quite active. Insecticides labeled for control of beetles such as Conserve, Orthene, Duraguard, or Talstar N may be options for management.
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3-Lined Potato Beetles |
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Leanne Pundt photos -- click for a larger image |
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Aphids, mites and thrips continue to be active on various greenhouse crops. See previous updates for more information.
Botrytis blight can still be seen on crowded crops. Continue to space plants as crops are sold.
If you would like to receive an email notice when new greenhouse updates are posted on the website, please email me at: leanne.pundt@uconn.edu . This will be an undisclosed list, and your email address will remain private.
| New England Greenhouse Update now online. University Extension Specialists in New England, in conjunction with USDA's Northeast Sustainable Agriculture Research and Education, contribute information to this new website. Timely updates are provided for commercial growers of greenhouse crops and flowers in Massachusetts, Connecticut and Rhode Island. You can use this additional resource for more information about current observations and recommendations on environmentally safe production practices. |
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GREENHOUSE IPM COORDINATOR (commercial interests and growers) |
LEANNE PUNDT | 860-626-6240 |
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