Some issues that come up in the greenhouse are not necessarily first on the priority list, but can have significant implications for crop production and Integrated Pest Management (IPM).
by Jim Mussoni, Private IPM Scout, and Jason Lanier, UMass Extension
As benches begin to fill up and conditions get warmer, weed germination has been observed to be well underway in some facilities. When working in the greenhouse, be sure to a look under benches and in those tucked-away corners to assess the weed situation. Uncontrolled weeds can be great reservoirs for insect infestations and disease inoculum. Tough pests such as aphids, mites, thrips and whiteflies can become established on weeds in the greenhouse. If weeds are not managed properly and in a timely fashion, it is also likely that such insect populations will go unnoticed and untreated. Now is a great time to do some scouting and develop a plan to get on top of any weeds that may be present… these efforts will pay dividends in the form of a cleaner and healthier crop later. Remember that when using herbicides in the greenhouse it is critical to follow all label directions and to take the utmost care for application due to the risk of damaging crop plants.
Weeds under a greenhouse bench (photo by Jim Mussoni)
Check out recent research by Bryan Brown and Brian Eshenaur at Cornell that investigated the use of rice hull much and solarization for greenhouse and nursery weed control: https://hdl.handle.net/1813/64540
Another problem that may be overlooked is rodents, such as mice and rats. Impacts from rodents can range from a nuisance, such as chewing on plastic pots, to a significant concern in the case of feeding on seeds or seedlings, to even a potential food safety matter in the case of edible crops. Baits and traps are effective means of control when executed properly, as well as physical barriers to prevent entry, especially into sensitive areas.
A baited mouse trap placed in a seedling tray (photo by Jim Mussoni)
Finally, the importance of keeping growing areas clean and using good common sense cannot be overemphasized. This means regular cleaning of benches and floors, pots and trays, and potting areas. Specific tools should be designated for cleaning of the floor, and others reserved for bench tops. This goes a long way to preventing the spread of disease and contaminants. Keeping the hose end off the floor is particularly important too, for the same reasons.
An irrigation wand hung properly off of the floor (photo by Jim Mussoni)