2012 ORGANIC CABBAGE TRIAL

This is a demonstration project:  A single field without controls or replications for statistical analysis.  The purpose of this trial is to explore possibilities before launching a full-scale research program.

Experimental Location:  Homestead, Florida, United States of America.  25.47 degrees North Latitude, 80.52 degrees West Longitude.

Climate:  Homestead has a semi-tropical monsoon climate with a hot, humid summer and a cooler, drier winter.  Average annual temperature = 74.8 degrees Fahrenheit = 23.75 degrees Centigrade.  Average annual rainfall = 58.23 inches = 147.90 centimeters.  Average January low temperature = 56 degrees Fahrenheit = 13.2 degrees Centigrade.  Average January high temperature = 77 degrees Fahrenheit = 24.8 degrees Centigrade.  Frost Free Growing Season = approximately 355 days.  Homestead gets about 5 to 10 frosts (36 degrees Fahrenheit) and freezes (32 degrees Fahrenheit) each winter.

Experimental Plot Size:  1 acre = 208 feet x 208 feet (approximately).

Soil Type:  Everglades Peat = Muck

Crop Rotation:  Sunn Hemp (Crotalaria juncea) was planted in spring 2012 to suppress weeds and control root knot nematodes.  Hemp cover crop was shredded with a forage chopper then Crimson Clover (Trifolium incarnatum) was broadcast seeded over hemp mulched field.  Cabbage seedlings were transplanted into rotary mowed crimson clover in November 2012.

Tillage:  Field was mulched using a common silage chopper.  Crimson clover was cut with a rotary mower.  Cabbage seedlings were planted using a no-till transplanter with a fluted coulter.

Plants Per Acre:  Cabbage transplants were set 18 inches apart in rows 30 inches apart = approximately 11,000 plants per acre.  (138 plants per row x 83 rows per acre = 11,454 plants per acre exactly).  80% field survival is common so final plant density = approximately 9,000 plants per acre.

Crop Variety:  Brassica oleracea cultivated variety “Golden Acre”.  This is an early season (58 day) round cabbage with small heads averaging 3 to 4 pounds each.

Common Weed Varieties:  Bull Thistle (Cirsium vulgare), Coffee Senna (Senna occidentalis), Hemp Sesbania (Sesbania exaltata), Morning Glory (Ipomoea species), Lambs Quarters (Chenopodium album), and Pigweed (Amaranthus blitum).

Weed Management:  Sunn hemp cover crop and crimson clover living mulch eliminated most weeds.  Field was better than 95% weed free so no herbicides were used for this trial.

Weed Spacing:  Approximately 2,200 weeds grew above the crimson clover living mulch = approximately 1 weed per 19.8 square feet.  Clumps of weeds were hand thinned to single weeds spaced about 4 to 5 feet apart.

Irrigation:  Overhead sprinkler irrigation, 1 to 2 inches applied each week as needed.

Organic Fertilizers:  Greensand and colloidal phosphate rock were broadcast with sunn hemp seed according to soil test recommendations.  Hemp seed was covered with 20 tons = 40,000 pounds of composted stable bedding.  Fish emulsion and liquid seaweed (Kelp) were used as starter fertilizers for cabbage transplants.

Insect Control:  Cabbage plants were sprayed with a harmless biological insecticide “BT” = Bacillus thuringiensis subspecies kurstaki strain SA-12 every 7 to 10 days throughout the growing season.  BT is a naturally occurring bacterial disease that kills caterpillars = juvenile forms of moths and butterflies.

Cabbage Yield:  Approximately 9,000 marketable heads were harvested.  Average head weight = approximately 3.375 pounds = 3 pounds 6 ounces (normal range is 3 to 4 pounds).  Yield per acre = approximately 30,000 pounds = 15 tons.

Production Costs:  $5,924 per acre (mostly for amortized irrigation system and farm machinery).

Cabbage Income:  30,000 pounds cabbage (9,000 marketable heads) x $0.35 per pound organic produce premium wholesale price = $10,500 gross income.

Net Income:  $10,500 gross income – $5,924 production costs = $4,576 net income from 1 acre of organic cabbage sold wholesale.  ($4,576 net income / $10,500 gross income) x 100 = 43.58% before tax profit.  ($4,576 net income / $5,924 production cost) x 100 = 77.2451 = 77% gross return on investment.

Agronomy Notes:

>>>  Most south Florida soils are coarse sands with very low humus content (often less than 2%).  Large amounts of organic matter must be added to these soils to keep them productive.  Cash crops must be rotated with soil building cover crops in order to maintain humus levels at 3% or above.

>>>  Muck soils also require large amounts of organic matter to replace humus lost to accelerated decomposition when swamps are drained.  Drainage and cultivation expose peat soils to large amounts of oxygen.  Rapid oxidation causes soil subsidence if organic matter is not replaced.

>>>  Root knot nematodes are serious agricultural pests in south Florida.  The most economical control method is to rotate cash crops with highly nematode-resistant cover crops like Sunn Hemp (Crotalaria juncea), Velvet Bean (Mucuna deeringiana), Cowpea (Vigna unguiculata), or Hairy Indigo (Indigofera hirsuta).

>>>  Sunn hemp, forage maize, and silage corn produce enormous amounts of organic matter for soil improvement (surface mulch or green manure).  Few farmers use hemp or maize as green manure or mulch crops because the plants must first be shredded in order to decompose quickly.  (If long-lasting mulch is desired, knock down cover crops with a roller-crimper then plant through dead mulch with a no-till seeder or transplanter).

>>>  Widely spaced weeds did not appear to have any negative effects on cabbage yield or quality.  Many cabbages growing near weeds were larger than those without any weed competition.  Light shade may be beneficial for cabbage growth.

>>>  Crimson Clover (Trifolium incarnatum) is often sown along Florida highways because it has large flowers.  Crimson clover makes good living mulch because it normally grows only 6 to 12 inches high.  Ideal living mulches grow short so they do not compete with crop plants for light.

Would You Like To Know More?  Please contact the Author directly if you have any questions or need additional information about using living mulches for weed control.

Please visit:  http://www.worldagriculturesolutions.com  — or —  send your questions to:  Agriculture Solutions, 413 Cedar Drive, Moon Township, Pennsylvania, 15108 United States of America  — or —  send an e-mail to:  Eric Koperek = worldagriculturesolutions@gmail.com

About the Author:  Mr. Koperek is a plant breeder who farms in Pennsylvania during the summer and Florida during the winter.  (Growing 2 generations each year greatly speeds development of new crop varieties).

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2012 TOMATO AND SWEET POTATO POLYCULTURE TRIAL

This is a demonstration project:  A single field without controls or replications for statistical analysis.  The purpose of this trial is to explore possibilities before launching a full-scale research program.

Experimental Location:  Butler County, Pennsylvania, United States of America.  40.8606 degrees North Latitude, 79.8947 degrees West Longitude.

Climate:  Butler County has a temperate climate with cold winters.  Average annual temperature = 48.75 degrees Fahrenheit = 9.3 degrees Centigrade.  Average yearly rainfall = 41.85 inches = 106.299 centimeters.  Average yearly snowfall = 37 inches = 93.98 centimeters.  Average Last Spring Frost (36 degrees Fahrenheit) = 26 May.  Average First Fall Frost (36 degrees Fahrenheit) = 23 September.  Frost Free Growing Season = 119 days (about 4 months).

Experimental Plot Size:  1 acre = 208 feet x 208 feet (approximately).

Soil Type:  Heavy Clay Loam

Crop Rotation:  Organic herbicide (vinegar & citric acid) applied spring 2011 followed by broadcast seeded buckwheat (Fagopyrum esculentum) cover crop mowed at first flower then over-seeded with Dutch white clover (Trifolium repens).

Organic Herbicide:  10% Glacial Acetic Acid (liquid) + 5% Citric Acid (powder) + 83% Pure Water (rain water) + 2% Wetting Agent (surfactant) = 100% by weight.

Tillage:  Field rotary mowed prior to planting with a no-till transplanter.

Plants Per Acre:  Tomato transplants set 4 feet apart in rows 4 feet apart = 52 plants per row x 52 rows per acre = 2,704 tomato transplants per acre.  1 sweet potato transplant set every 2 feet between tomato plants in the row = 50 plants per row x 52 rows per acre = 2,600 sweet potato transplants per acre.

Crop Varieties:  Determinate, open pollinated, “Stake-Less” tomatoes (with thick upright stems).  “O’Henry” yellow sweet potato variety.

Predominate Weed Varieties:  Pigweed (Amaranthus blitum), Lambs Quarters (Chenopodium album), Bull Thistle (Cirsium vulgare), Foxtail Millet (Setaria species), and Morning Glory (Ipomoeae species).

Weed Management:  Organic herbicide, buckwheat cover crop, and Dutch white clover provided approximately 80% weed-free field for this trial.

Weed Spacing:  Clumps of broadleaf weeds were hand thinned to 1 plant every 3 feet.  Hand pruning weeds took the local scout troop (14 boys) about 4 hours.  Approximate weed density = 5,000 weeds per acre.

Irrigation:  Overhead sprinkler irrigation, 1 to 2 inches per week as needed.

Fertilizer:  Soluble nitrogen (62 pounds), phosphorous (76 pounds), potash (359 pounds), and magnesium (38 pounds) applied with irrigation water according to soil test recommendations.  Clover living mulch supplies about 100 pounds of nitrogen per acre.  2 tons of agricultural gypsum applied in spring 2011 to provide adequate sulfur for Dutch white clover.

Tomato Yield:  Approximately 51,000 pounds = 25.5 tons of marketable fruit per acre = 19 pounds per plant (pick-your-own).  High yield = 37 pounds per plant (controlled harvest).  Low yield = 7 to 8 pounds per plant (destructive harvest).

Sweet Potato Yield:  Approximately 10,000 pounds = 5 tons of marketable, first-grade roots per acre = 3.8 pounds per plant.

Planting Cost:  $4,025 per acre (mostly for amortized irrigation system and deer fencing).

Harvest Cost:  $1,810 per acre.  Sweet potato harvest took the local
Scout troop (14 boys) three days or approximately 300 hours to lift and sort roots by hand.

Marketing Cost:  $2,900 per acre (mostly for sales labor, newspaper advertisements, and post card mailings to previous customers).

Total Production Costs:  $4,025 planting cost + $1,810 harvest cost + $2,900 marketing cost = $8,735 total cost to grow and sell vegetables.

Tomato Income:  Fruits sold for canning at $0.25 per pound pick-your-own x 51,000 pounds harvested = $12,750 gross income.

Sweet Potato Income:  Roots sold for $1.50 per 5-pound bag.  10,000 pounds of number 1 roots harvested / 5 pounds per bag = 2,000 bags x $1.50 per bag = $3,000 gross income.

Net Income:  $15,750 income from vegetable sales – $8,735 cost to grow and market vegetables = $7,015 net income per acre.  $7,015 net income / $15,750 gross income = 0.4453968 x 100 = 44.5% profit.  [$7,015 net income / $8,735 cost] x 100 = 80.30% return on investment.

Agronomy Notes:

>>>  Dutch white clover living mulch normally provides 90% to 95% weed-free fields.  This season’s relatively poor 80% control rate is unexplained but provided an opportunity to examine the effect of weed spacing on crop growth and yields.  Widely spaced weeds (3 feet apart) appeared to have little or no effect on crop yields but did lower tomato hornworm populations — insecticides were not needed for the 2012 crop year.

>>>  Sweet potato yields were 50% less than normal because of low plant density; transplants were set only within tomato rows, not between tomato rows.

>>>  Buckwheat (Fagopyrum esculentum) is an ideal cover crop for non-chemical weed control.  Buckwheat grows very quickly (8 inches per week) to a maximum height of approximately 50 inches (4 feet 2 inches) in 6 weeks.  Seeds ripen at 10 to 11 weeks.  (Buckwheat must be cut at flowering to prevent reseeding).  Buckwheat’s fast growth and dense shade eliminate most weeds.

>>>  Sweet potatoes (Ipomoea batatas) make good living mulch:  They thrive in poor soil, require no insecticides, and established plants overrun most weeds.

Would You Like To Know More?  Please contact the Author directly if you have any questions or need additional information about using living mulches for weed control in vegetable crops.

Eric Koperek = worldagriculturesolutions@gmail.com

About The Author:  Mr. Koperek is a plant breeder who farms in Pennsylvania during the summer and Florida during the winter.  (Growing 2 generations per year greatly speeds development of new crop varieties).