in living host cells. Its vegetative phase consists of a multinucleate mass of protoplasm lacking a cell wall (plasmodium or slime mold). Although the organism primarily attacks members of the Cruciferae, the intensity of disease caused on different crops...
(see "Host Range") varies. The organism also exists as many specialized forms or races, the variation in plant resistance and ability to survive in different areas being explained thereby. Symptoms Clubroot may develop extensively on plant roots before...

, including insecticides that may be approved for organic production: veg-guidelines.cce.cornell.edu. 5 Boivin, G. and D. L. Benoit. 1987. Predicting onion maggot (Diptera: Anthomyiidae) flights in southwestern Québec using degree-days and common weeds...
entry points for bacterial pathogens that can cause bulbs to rot. Feeding by third-generation larvae on mature onion bulbs can result in an unmarketable product (Fig. 4). Even after onions are undercut, windrowed, and left to dry in the field, bulbs may...

hardens and takes on a reddish brown color. Photo: M. Frye �Biology American cockroaches live in humid areas such as bathrooms and basements, and can occupy air gaps or broken sewer lines where they feed on decaying organic matter. Although adults have...
of an infestation or show the direction of movement for trapped cockroaches. In general, baiting systems have several advantages over traditional pesticides. Baits are typically semi-solid or solid products that confine active ingredients to small placements...

Fire blight, caused by the bacterium Erwinia amylovora, is one of the most destructive diseases in apple and pear production. Fire blight can infect other members of the rose family including quince, juneberry, hawthorne, mountain...

success in recruiting children to organize a no-feeding campaign. Exclusion Exclusion is most effective on small ponds and along shorelines of larger water bodies when geese are flightless during the summer molting period. Geese prefer to be able to easily...
must be humanely euthanized. Sometime the geese are sent to a poultry processor, and the meat is donated to local food banks. Reproductive control Until recently, there was a product for the temporary sterilization of geese. The active ingredient...

) , Colletotrichum can cause severe rotting of below-ground plant parts and early plant decline leading to discolored tubers and reduce~ yields. The same black dot organism causes anthracnose or npe-fru1t disease of tomato, and can occur on other solanaceous crops...
, the organism does not penetrate intact tuber skin, but can grow and sporulate on damaged tissue. This limited growth, however, does not appear to provide entry sites for secondary fungal or bacterial invaders in stored tubers. In a three-month greenhouse test...

or other organic debris adjacent to the home. Increasing ventilation and using thick plastic in basements and crawl spaces can help remediate moisture problems. Outdoors, a vegetation free zone of two feet around the building with no plants, mulch...
or organic debris (such as leaves, wood, or compost) can be used to reduce moisture around the foundation and deter pest populations. Cracks and crevices in the foundation or gaps around windows and doors are common entry points for earwigs and other pests...

-CSREES. Production team: Karen English and Mary Woodsen. Photographs: Lang Elliot, Joe Ogrodnick, Robert McNiel, Bird Barrier America, Inc., Cornell University Photography, Jim Kalisch (Dep’t. of Entomology, Univ. of Nebraska-Lincoln). Cornell Cooperative Extension...
organic land care ❏ Test, don’t guess: How to submit plant and insect samples for diagnosis ❏ IPM for Homes: How to use IPM to uninvite residential pests ❏ What’s all the buzz about mosquitoes? ❏ Evict and exile mice from your home ❏ The year...

rot develops slowly and may not be severe until quite late into the storage period. This decay may allow the entry of secondary organisms such as Fusarium fungi and soft rot bacteria. �CONTROL The following measures will help prevent the occurrence...
. Surface tubers infected by conidia washed from leaves. ~,'~'~:~~"~:,~~:~~,-'".~"~~~~"'~",~",~~~ ~~~~~' ~~"~ "Target" spots Early Blight Disease Cycle Adapted in part from North Dakota State University Extension Bulletin 26, 1976, 'Potato Production...

-green, yellowish to brownish areas of irregular size and shape (oval tocylindrical) on infected leaves or seed stalks (Fig. 1). These areas may consist of alternating yellow and green layers of tissue. The causal organism of DM produces fruiting bodies and spores...
the night and morning hours. Secondary Spread The mycelium of DM in leaves of infected onion plants in commercial bulb production fields produces a new crop of spores called conidia in cycles of approximately 11-15 days. As the upper portions of a leaf...