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Home  > Question of the Week

Question of the Week

Permalink How can I organically control darkling beetles/lesser mealworms in my poultry house?

Answer: Lesser mealworms, also known as darkling beetles, are associated with poultry litter and manure accumulations. They can cause significant damage by boring into structural materials, and they also serve as a vector for several poultry diseases. The adults are half-inch long, dark brown to black beetles, and the larvae are light yellow to brown colored and about a half to a quarter inch long. Both adults and larvae live in the poultry litter, where they feed on poultry feed and dried bird droppings. Moisture from waterers or other sources is necessary for their survival. They are usually found where there is moisture and/or where the litter is looser and deeper. The larvae and adults tend to accumulate under anything lying on or just under the surface of the litter. Floor feeders provide excellent places for them to hide. If nothing is available, they will stay around the edges of caked litter.

Good litter management can greatly reduce numbers of these beetles. Keep the litter as dry as possible, pack down loose litter, and where possible use feeders and waterers that do not sit on the litter but attach to the sides of the coop. Regular complete cleanout and disposal of litter, especially in freezing temperatures that will kill the beetles, is advised.

It is virtually impossible to eliminate these insects from a house with insecticides. They are protected down in the litter and the litter itself may bind the products and reduce their effectiveness. However, diatomaceous earth (DE) may help. The poultry house and litter, nest boxes, and areas where birds take dust baths may all be dusted with DE. Non-heated forms of DE are allowed without restrictions in an organic system. Be sure to use food-grade quality DE (not the DE sold for use in pool and other filters) with crystalline silica content at or below 1%. DE with crystalline silica content of 3% or higher is dangerous and should be strictly avoided.

When these methods are insufficient, pyrethrum may be used in an organic production system. Pyrethrum is an effective, though expensive, means of external parasite control. Both pure pyrethrum and pyrethrum/DE combinations are available. Pyrethrum dust may be used in poultry housing and can be applied to the birds themselves. The annotation in the Organic Materials Review Institute's Generic Materials list specifies that pyrethrum may be used as an external parasiticide. Synthetic pyrethrins and pyrethrum products formulated with piperonyl butoxide are not allowed. Producers must comply with all label instructions for administration of pyrethrum-based parasiticides to livestock, in addition to complying with the specific regulations pertaining to organic production systems. Producers need to document previous attempts to control parasites using alternative means, such as those described above.

For more information, see:

Poultry House Management for Alternative Production, by ATTRA

Pest Management on Poultry Farms, by Connecticut Cooperative Extension

Poultry Pest Management, by from Alabama Cooperative Extension

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Permalink What advice do you have for designing a vegetable cooler utilizing an insulated truck and a CoolBot system?

Answer: There are several important issues with designing and using a small cooler like the one you describe. First is the shelving, which should not be constructed of wood or fiber materials such as plywood or other compressed-wood products. The best shelving would be metal with an epoxy coating. This type of shelving may seem expensive but will likely be required under the new Food Safety Modernization Act that will begin implementation sometime next year.

Regarding the design of your cooler, you want to make sure that no containers are stored on the ground. You should always keep the accumulation of water spots to a minimum, but it is easy for standing water to develop in produce coolers and you want to keep all stored produce out of that water at all times.

In order to maximize the amount of product you can store in the cooler, avoid having the bottom shelf too high off the ground or you will limit the amount of containers you can stack. A cooler that is 8’x12’x8’ will have a maximum of 768 cubic feet of storage. You probably will have a 3-foot door and you will need to leave a 4-foot hallway into the cooler, leaving only 672 cubic feet of storage. If the bottom shelf is one foot off the ground, you will lose another 96 cubic feet of storage. Instead, consider raising the bottom shelf only two to three inches off the ground.

You should also understand the cooling requirements of the different products you are going to harvest on your farm, and also which products should not be stored with each other. For example, onions give off odors that can easily be absorbed by fruit being stored in the same cooler. Other products such as tomatoes give off ethylene gas, which can speed up the ripening of other products and shorten their shelf life.

If these considerations are properly addressed, you should be on your way to an efficient and organized produce cooler.

To learn more about appropriate production practices, careful harvesting, and proper packaging, storage, and transport of fresh farm products, see the ATTRA publication Postharvest Handling of Fruits and Vegetables, available at

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Permalink When experimenting with till versus no-till, what constitutes tillage?

Answer: A good definition of tillage is the preparation of soil by mechanical agitation for planting crops. Any disturbance, small or large, that prepares the soil for planting constitutes tillage.

One type of tillage is primary tillage, which is the breaking up of sod ground or other ground that has not been worked for planting for a long time. This consists of plowing deeply and turning sod and residue into the ground. This was traditionally done with a moldboard plow and can leave the soil vulnerable to erosion. Chisel plows and heavy disc harrows can also be used for primary tillage and will leave residue closer to the soil surface.

Secondary tillage is not as deep and is used to prepare a finer seedbed for planting. A disc harrow, spike tooth harrow or a rototiller would be examples of secondary tillage equipment.

Cultivation for weed control with mechanical cultivators or a hoe can also be considered tillage of the soil, even though it only works the top few inches of soil.

There are many advantages to no-till and reduced tillage, including better soil health, reduced erosion, reduced energy use, and water conservation. Organic no-till systems are really reduced tillage systems because some form of primary tillage is needed to control weeds. Herbicides are used for this in conventional no-till so the ground doesn’t need to be tilled prior to planting. Once weed control is achieved in an organic system, and a cover crop is established, then a cash crop can be planted without additional tillage. No tillage is needed for about five seasons, after which weeds may once again become a problem.

The ATTRA publication Pursuing Conservation Tillage for Organic Crop Production describes the methods and strategies used to reduce tillage in an organic system. Conservation tillage refers to a number of strategies and techniques for establishing crops in the previous crop's residues, which are purposely left on the soil surface. The principal benefits of conservation tillage are improved water conservation and reduced soil erosion. Additional potential benefits include reduced fuel consumption, flexibility in planting and harvesting, reduced labor requirements, and improved soil tilth. Two of the most common conservation tillage systems, ridge tillage and no-till, are discussed in this ATTRA publication.

Rodale Institute has been researching and practicing organic no-till techniques. You can read about their equipment and systems at

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Permalink Do the allelopathic characteristics of sweet potatoes influence subsequent crops? I want to plant carrots following my sweet potatoes and I’m concerned about decreased yield and increased pest pressure.

Answer: Your concerns for planting carrots after sweet potatoes are valid. Allelopathy is a chemical process that many plant species use to prevent other types of plants from growing too close. These chemicals are called allelochemicals. Depending on the plant, allelopathic substances can be released from a plant's flowers, leaves, leaf debris and leaf mulch, stems, bark, roots, or soil surrounding the roots. Sweet potatoes release these defensive chemicals into the soil through their roots in a process called exudation. Those chemicals are absorbed by the roots of other nearby plants, which are damaged. While some of the chemicals biodegrade over time, others can persist in the soil.

Research shows two tuber crops should not be planted in the same rotation because of disease and pest purposes. Planning a crop rotation scheme that allows a few years between potato crops on the same land is recommended. For organic production, a lengthy rotation from four to seven years generally assures good plant and soil health. A lengthy rotation also reduces long-term reliance on expensive inputs and increases the percentage of marketable potatoes. A good rotation includes crops that are not hosts to common potato pests. A good rotation also includes green manures that add nutrients and organic matter to the soil. Additionally, planting a legume crop after a tuber crop will add nitrogen and other essential minerals to the soil.

Early research suggests that allelopaths can be used as effective herbicides for organic weed control. For example, an allelopathic crop might be beneficial in controlling weeds by planting it in rotation with other crops.

For more information, consult the ATTRA publication Potatoes: Organic Production and Marketing at

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