home
about the program
calendar
what's new
crop production
marketing
farm profiles
grower resources
buy local
farmers' markets
web resources
contact us


Website created
and maintained
by Debbie Roos,
Ag Extension Agent.

Site Map


©2007
North Carolina
Cooperative Extension

 

Sunny Slope Greenhouses

Photos and text by Debbie Roos, Agricultural Extension Agent.

Page 2

 

This is a 2-3 week old transplant. A good transplant shoot is as wide as it is tall. The trays that the seedlings are produced in have a hole in the bottom that air prunes the tap root which encourages feeder root development.

 

Dave transplants seedlings into the larger cells. Note how every other row is filled to give plants room to develop. Dave selects and plants only the best 2,500 seedlings out of the original 3,300 planted. As the transplants grow, light and temperature regimes are adjusted to maximize plant growth and to compensate for weather conditions.

 

These plants have been growing in the larger cells for about 2-3 weeks and are filling in the extra space.

 

These plants are ready for transplanting into the ground. Dave and Jim will select and plant the best 2,200 plants out of these 2,500 transplants.

 

Planting is done the week between Christmas and New Year's.

While the transplants have been growing, Jim and Dave have incorporated the compost and lime (if indicated on soil test reports), tilled the beds, laid out and tested drip irrigation lines, covered the beds with white plastic, and cut holes for plants. Black plastic would absorb heat and reduce fuel costs but white plastic reflects light better and light is the biggest factor that they can't control. Remember that they are growing tomatoes at the time of year when days are the shortest and light level is the lowest.

Before the crop is planted they run the heaters for 24 hours and submit air samples to NCSU to make sure that no harmful gases are emitted. They use five 220,000 BTU furnaces, one for each bay. Fuel is the major expense. On a night when it gets down to 32° F, they burn 100 gallons of propane.

 

It takes about a day per bay to transplant and apply a starter fertilizer solution to each plant to help establish roots. During the growing season, fertilizer needs are determined based on plant tissue analysis. Every 7-10 days, they send a sampling of tomato leaves off for analysis and then apply fertilizer based on the resulting report. Water-soluble fertilizer is injected into the drip irrigation system.

You can see part of the trellis system in this photo: notice the bobbins hanging in the top left of the photo - the bobbins are placed on overhead wires, one above each plant, and each contains 25 feet of twine that is lowered down to touch the plant.

 

Plant spacing varies throughout the greenhouses but each plant has approximately 4 square feet. Plants in interior bays get about 20% more space because they don't get as much light. Note that the plants still are just about as wide as they are tall.

Around January 1, right after transplanting, Jim and Dave inject millions of beneficial nematodes through the irrigation system to control soil-borne pests such as thrips and fungus gnats. Nematodes are tiny roundworms that live in the soil. Many species feed on plant roots and are considered pests but other species are entomopathogenic, or parasites of insects. These beneficial nematodes, purchased from suppliers that specialize in biological control agents, parasitize insects that spend all or part of their life cycle in the soil.

 

Speaking of biological control agents...another natural enemy that Jim and Dave purchase and release is the Trichogramma wasp, an egg parasitoid that seeks out eggs of the tomato fruitworm, which damages fruit. These micro-wasps, measuring only about 1/10" in size, are too fragile to be shipped as adults and so they are shipped ready to hatch inside parasitized eggs glued to a card. Each card contains approximately 120,000 eggs.


Jim cuts the cards into individual strips to disperse around the greenhouse.

 

Close-up of parasitized eggs, which are dark with developing wasps inside. Normal eggs are white.

 

Jim attaches the cards to the plants in the areas that he knows are most susceptible to fruitworms - usually near vents and doors and openings.

 

The adults emerge from the eggs and search for fruitworm eggs to parasitize in the greenhouse. The wasps are ordered and released monthly in the spring as the temperatures warm up and the fruitworm moths become active and start laying eggs.

Sunny Slope employs other biological control agents on an as-needed basis, including predatory lady beetles and lacewing larvae, parasitic Aphidius wasps and predatory Aphidoletes midge larvae for aphid control, parasitic Encarsia wasps for whitefly control, and parasitic nematodes.

 

Page 2

 

 

This page last updated January 16, 2006.

 

North Carolina Cooperative Extension, Chatham County Center
P.O. Box 279, Pittsboro, NC 27312
919-542-8202

Website created and maintained by Debbie Roos, Agricultural Extension Agent.

URL: http://chatham.ces.ncsu.edu/growingsmallfarms

North Carolina Cooperative Extension is an educational partnership helping people put research-based
knowledge to work for economic prosperity, environmental stewardship and an improved quality of life.