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Getting Ready for Transplanting- February 12, 2009

Jane Hoehaver and her staff are busy preparing for the summer planting season.  They are planting seeds for peppers, tomatoes, Mexican sunflower, licorice mint, alyssum, calendula, and bronze fennel among other farmscaping plants.  A lesson they learned from last year is to seed all the licorice mint early because it grows slowly.  Planted in January, the licorice mint has had extra lighting, which has made all the difference in growth.  The staff is on target to plant the rest of the farmscaping plants by the February 22.  On March 1 peppers will be seeded and then on March 30 all the tomatoes seeds will be planted.

We are growing Amelia tomatoes, which are tomato spotted wilt resistant.  Organic seed is not available so we are using untreated seed purchased from Seedway.  The pepper that we are planting is Hungarian hot wax, which is organically grown and can be purchased from Park’s Seed or Seeds of Change.

Beneficial Insects an Update (see "Beneficial Insects" below to read how Jane established these and the challenges she faced back in 2007)

To aid with insect pests, Jane has trays of banker plants, specifically barley. She will inoculate the barley with cereal aphids. The cereal aphids only feed on monocots, or grasses, so they will not bother the tomato and pepper; they will serve as a food source for beneficial insects. When the cereal aphid populations have built up, usually in about 3 weeks, she releases beneficial insects.  These insects, aphid parasites, Aphidius colemanii, and minute pirate bugs, are released directly on the banker plants where they will feed on the cereal aphids. Aphidius attack aphids and the minute pirate bugs go after aphids, thrips, and some mites. Later, when the tomato- and pepper-eating aphids and other insect pests come, the beneficials will be plentiful enough to protect the plants.

Worm castings

The greenhouse staff is using only worm castings as potting mix.  Jane says transplant plugs in the worm castings only require fertilizer once before the plants go to the field.  Bought locally, the worm castings come from Scott Lueck at Bemastan Worm Farm. 

Beneficial Insects (2007)

Jane Hoehaver, director of the Plant Science Research Center, likes to feed her beneficial insects well—with aphids. 

Jane explains, “We are trying to establish banker plants, which are winter and summer barley.  Basically, they hold cereal aphids, which in turn serve as a food source for beneficial insects that we release.  The cereal aphids only feed on monocots, or grasses, so they won’t bother our tomato and pepper.” 

When she releases beneficial insects, she will do so directly on the banker plants to give the insects an immediate food source: the aphids. Later, when the tomato- and pepper-eating aphids come, the beneficials will be hungry and plentiful enough to protect the plants. Jane releases two beneficials: parasitic wasps and gall midges.

The winter and summer barley are available at Seeds of Change and Johnny’s Seeds.  Both are organic seeds.

Update

"We will have to repeat the test after the organic transplants are delivered to the field. Before we were able to innoculate the banker plants with the cereal aphids and get beneficials established in the zone, we were inundated with green peach aphids. Along with the infestation of aphids, we also discovered parasitic wasps that found their way into the greenhouse.

"Although we purchased beneficials to combat the problem, the insectory that we use had problems with their insect colonies and delayed our original shipments until April 17. In the mean time, we used neem oil sprays to control the aphids. Control is the key word as neem does not eliminate them 100%; it only decreases the numbers. This spray kills the parasitic wasps as well.

"The good news is that the developing parasitic wasps housed in the aphid mummies on the plants are protected from the sprays by the deteriorating body of the aphid. So, if the amount of mummies is relatively high we can spray and still have a future generation of wasps available. This does leave a lag between the beneficials and the pests as the pest populations build more quickly than the beneficial population. At this point, to try and evaluate the banker plant system would be pointless. When our production is over, I'd like to empty and clean the zone, start fresh banker plants, inoculate with aphids then beneficial insects, and re-evaluate the system."

Mummified aphids parasitized by wasps.  Photo by Alton N. Sparks, Jr. Photo courtesy of ipmimages.org.	Barley as a banker plant for attracting aphids away from pepper.  Photo by Jane Hoehaver.

  To read more about these beneficials visit http://www.biobest.org/