vegetable crops – plsc 451/551 lesson 10, organic strategies instructor: stephen l. love aberdeen...
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Vegetable Crops – PLSC 451/551Lesson 10, Organic Strategies
Instructor:Stephen L. LoveAberdeen R & E Center1693 S 2700 WAberdeen, ID 83210Phone: 397-4181 Fax: 397-4311Email: [email protected]
Choosing a Production Location
Concepts and Objectives
Minimize the need for unwanted inputs
Avoid serious production barriers
Choosing a Production Site
Strategies
Choose property that is located near the market delivery point
Seek soil with high levels of natural fertility and good textural and structural characteristics
Select a site that is free from serious chronic weed, insect, or disease problems
Choosing a Production Site
Specifics – market location
Owner-operator marketing
Best located near a major population center
Access to farmer’s market
Vegetable stand on major travel route
Local grocer, restaurant, specialty market
Wholesale or cooperative marketing
Best located near produce collection point
Choosing a Production Site
Specifics – soil characteristics
Naturally high in organic matter
Naturally high in P, K, S
Good water holding capacity in infiltration
Loams, sandy loams, silt loams
(Avoid heavy clay or very sandy soils)
Choosing a Production Site
Specifics – chronic pest problems
Low weed seed bank (historically good control)
Free of perennial, deep-rooted weed problems
(e.g. bindweed, quackgrass, nutsedge, etc.)
Free of consistent, chronic insect or disease problems that affect the intended crops
(e.g. nematodes, soil wilt diseases, cutworms, wireworms, etc.)
Plant and Seed Selection
Concepts and Objectives
Use crop and variety choices to enhance production capabilities and market options
Utilize genetic resistance for controlling common problems
Avoid “importing” problems
Plant and Seed Selection
Strategies
Select crops and varieties that provide a market identity
Choose crops and varieties that are adapted to local conditions and organic techniques
Plant and Seed Selection
Strategies
Select varieties that are biologically competitive and resistant to locally common disease and insect problems
Purchase “organic” seed and transplants from a reputable producer
Inspect all seeds and transplants
Potato Variety Comparison
Variety Vert Eblt Lblt PLRV PVY
R. Burbank S MS S VS S
Defender VR R R MR MR
Important to have resistance to pathogens that require intense management inputs
Soil Management
Goals
Create a “healthy” soil
Maintain and/or increase organic matter
Improve soil structure and tilth
Supply nutrients with minimal added fertilizer
Improve water holding capacity and infiltration
Soil Management
Healthy Soils
Biologically active
Flourishing micro-organism population
Rapid breakdown of organic residues
Natural nutrient availability
Attractive to earthworms and other “aerifiers”
Suppressive to soil diseases
Suppressive Soils
Verticillium wilt incidence on potatoes
Treatment % Vert Wilt
Non-suppressive 62.6
Suppressive (OM added) 16.5
No soil fumigant 36.6
Soil fumigant 42.5
From Davis et al. (unpublished)
Soil Management
Sources of organic matter
Animal manures (cow, sheep, poultry, swine)
Compost (manure or plant residue based)
Green manures (grains, grasses, legumes, mustards, etc.)
Cover crops (winter grains, grasses, hardy legumes)
Crop residues (leftover or added)
Soil Management
Sources of organic matter
Animal manures (cow, sheep, poultry, swine)
Compost (manure or plant residue based)
Green manures (grains, grasses, legumes, mustards, etc.)
Cover crops (winter grains, grasses, hardy legumes)
Crop residues (leftover or added)
Soil Management
Sources of organic matter
Animal manures (cow, sheep, poultry, swine)
Compost (manure or plant residue based)
Green manures (grains, grasses, legumes, mustards, etc.)
Cover crops (winter grains, grasses, hardy legumes)
Crop residues (leftover or added)
Soil Management
Sources of organic matter
Animal manures (cow, sheep, poultry, swine)
Compost (manure or plant residue based)
Green manures (grains, grasses, legumes, mustards, etc.)
Cover crops (winter grains, grasses, hardy legumes)
Crop residues (leftover or added)
Soil Management
Sources of organic matter
Animal manures (cow, sheep, poultry, swine)
Compost (manure or plant residue based)
Green manures (grains, grasses, legumes, mustards, etc.)
Cover crops (winter grains, grasses, hardy legumes)
Crop residues (leftover or added)
Fertility Management
Soil testing
Zone sampling
Evaluate:
N, P, K, S, micronutrients (Zn, Mn, Mo)
pH
Organic matter content
Cation exchange capacity (CEC)
Fertility Management
Organic matter as a nutrient source
Nutrient release delayed – 20-50% first year
Not effective as a short-term nutrient source
Required in large amounts
Acts as a complete fertilizer, including micronutrients
Fertility Management
N requirement of selected crops
Low requirement - <120 lb/A
greens, beans, peas, squash
Medium requirement – 120-200 lb/A
carrots, corn, melons, onions, tomatoes
High requirement - >200 lb/A
cole crops, celery, potatoes
Fertility Management
Nutrient content of manures (lb/ton)
Type N P2O5 K2O
Beef 21 18 26
Swine 6 7 7
Horse 14 4 14
Sheep 14 9 25
Poultry 33 48 34Composts are generally lower but vary by source
Fertility Management
Nutrient contribution of green manures (lb/A)
Crop N P2O5 K2O
Hairy vetch 141 18 133
Clover 115 16 143
Austrian pea 144 19 159
Rye 89 18 108
Sullivan, 2003
Fertility Management
Other contributions of green manures and cover crops
Suppresses weeds
Minimizes soil erosion
Serves to capture nutrients
Improves soil structure
Enhances the growth of beneficial soil flora
Fertility Management
Crop residues
Important contributor to soil nutrition
Should be incorporated or left on surface
Contribution varies widely by crop
Fertility Management
Nutrient contribution organic fertilizers (%)
Fertilizer N P2O5 K2O
Bone meal 2 15 0
Blood meal 13 0 0
Fish emulsion 4 2 2
Soybean meal 7 2 2
Corn gluten 10 1 1Jett, 2004
Low nutrient content means high shipping and handling costs?!
Organic Vegetable Production
Fertility management – approved products
Algae Blood mealBone meal Chilean nitrateCompost CyanobacteriaDolomite Epsom saltsFish emulsions* Grape or apple pomadesGuano Hoof and horn mealHumic acids (nonfort.) Kelp meal
Organic Vegetable Production
Fertility management – approved products
K-mag Peat mossPhosphate rock Sodium nitrate (20%)Sugar beet lime Zinc or iron sulfateWorm castings Animal manureChelates EnzymesFish meal Gibberellic acidGreensand Gypsum
Organic Vegetable Production
Fertility management – approved products
Humates Kelp extracts
Kieserite Limestone
Mined material Mushroom compost
Perlite Potassium sulfate
Ground shells Elemental sulfur
Wood ashes
Organic Vegetable Production
Fertility management – prohibited products
Ammonia products Calcium nitrateSewage sludge Hydrated limeFortified humic acid Leather mealMagnesium nitrate Muriate of potashPhosphoric acid Potassium nitrateSuper phosphate Triple phosphateUrea Vitamin B-1
Weed Control
Cultural weed control
Rotate with competitive cropsEmploy incorporation of green manuresUtilize drip irrigationPlastic or organic mulches and/or row coversPlant crops at high population levelsUse competitive varieties
Weed Control
Mechanical weed control
Pre-irrigate and till prior to plantingPractice frequent cultivationUse flame-weedersEmploy hand labor (hoe, hoe, hoe)
Weed Control
Herbicidal weed controlThese products have been shown to provide some
control (finicky and not consistent)
Herbicidal soapsAcetic acidCitric acidCorn gluten
Weed Control
Weed control – prohibited products
Carrot oil
Synthetic growth regulators
Herbicides (all synthetic classes)
Weed oils
Insect Control
Control techniques
Plant resistant crops/varieties
Utilize beneficial insects and parasites
Plant borders with trap crops
Schedule planting to avoid damaging stages
Use approved insecticidal products as needed
Practice sanitation/fall plowing
Organic Vegetable Production
Beneficial insects and the pests they control:Lacewings thrips, aphids, mites, eggsLadybugs aphids, mites, eggsMinute pirate bug thrips, eggsBig-eyed bug thrips, aphids, eggsDamsel bug thrips, aphids, eggs, othersAssassin bug thrips, eggsSyrphid fly thrips, aphids, eggsParasitic wasps aphids, caterpillars, othersTwo-spotted stink bug Colorado potato beetle larvae
Organic Vegetable ProductionApproved insecticides:Bacillus thuringiensis Boric acidCryolite Dormant oilsHerbal preparations NematodesPyrethrums (natural) RyaniaSoaps GarlicDiatomaceous earth Insect extractsPheremones RotenoneTrapping substances Neem oilSpinosyn A&D Spinosad
Organic Vegetable Production
Prohibited insecticides:
Chlorinated hydrocarbons Carbamates
Methyl bromide Nicotine
Moth balls Methyl sulfoxide
Organophosphates Dimethyl sulfoxide
Pyrethroids (synthetic) Plant protectants
Organic Vegetable Production
Production methods – Disease control
Practice sanitation
Rogue infected plants
Control disease vectors
Utilize extended rotations
Maintain plant health/natural defenses
Use approved fungicidal compounds
Organic Vegetable Production
Disease control – approved products and practices
Natural antibiotics Copper hydroxide
Dormant oils Lime sulfur
Hydrogen peroxide Tree waxes/seals
Soil pasteurization Elemental sulfur
Organic Vegetable Production
Disease control – prohibited products and practices
Soil fumigants
Sterilants
Synthetic fungicides
Bactericides
Postharvest Management
Controlling postharvest rots/breakdown
Minimize injury during harvest
Harvest during cool temperatures
Employ proper cooling techniques
Remove damaged/rotting produce
Sanitize all handling equipment surfaces
Postharvest Management
Approved sanitizing or disinfecting products
Acetic acid
Organic ethyl alcohol
Quaternary ammonium salts
Bleach
Hydrogen peroxide
Postharvest Management
Prohibited products
Synthetic fungicides
Bactericides
Non-organically produced waxes and alcohols