Vegetable Crops – PLSC 451/551
Lesson 10, Organic Strategies
Instructor:
Stephen L. Love
Aberdeen R & E Center
1693 S 2700 W
Aberdeen, ID 83210
Phone: 397-4181 Fax: 397-4311
Email: slove@uidaho.edu
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
Traditional
Unique and unusual
Traditional
Unique and
unusual
Traditional
Unique and unusual
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
Defender
VR
MS
S
VS
S
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
Suppressive (OM added)
No soil fumigant
Soil fumigant
From Davis et al. (unpublished)
62.6
16.5
36.6
42.5
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
Beef
Swine
Horse
Sheep
Poultry
N
21
6
14
14
33
P2O5
18
7
4
9
48
K2O
26
7
14
25
34
Composts are generally lower but vary by source
Fertility Management
Nutrient contribution of green manures
(lb/A)
Crop
Hairy vetch
Clover
Austrian pea
Rye
Sullivan, 2003
N
141
115
144
89
P2O5
18
16
19
18
K2O
133
143
159
108
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
Bone meal
2
Blood meal
13
Fish emulsion 4
Soybean meal 7
Corn gluten 10
P2O5
15
0
2
2
1
K2O
0
0
2
2
1
Jett, 2004
Low nutrient content means high shipping and handling costs?!
Organic Vegetable Production
Fertility management – approved products
Algae
Bone meal
Compost
Dolomite
Fish emulsions*
Guano
Humic acids (nonfort.)
Blood meal
Chilean nitrate
Cyanobacteria
Epsom salts
Grape or apple pomades
Hoof and horn meal
Kelp meal
Organic Vegetable Production
Fertility management – approved products
K-mag
Phosphate rock
Sugar beet lime
Worm castings
Chelates
Fish meal
Greensand
Peat moss
Sodium nitrate (20%)
Zinc or iron sulfate
Animal manure
Enzymes
Gibberellic acid
Gypsum
Organic Vegetable Production
Fertility management – approved products
Humates
Kieserite
Mined material
Perlite
Ground shells
Wood ashes
Kelp extracts
Limestone
Mushroom compost
Potassium sulfate
Elemental sulfur
Organic Vegetable Production
Fertility management – prohibited products
Ammonia products
Sewage sludge
Fortified humic acid
Magnesium nitrate
Phosphoric acid
Super phosphate
Urea
Calcium nitrate
Hydrated lime
Leather meal
Muriate of potash
Potassium nitrate
Triple phosphate
Vitamin B-1
Weed Control
Cultural weed control
Rotate with competitive crops
Employ incorporation of green manures
Utilize drip irrigation
Plastic or organic mulches and/or row covers
Plant crops at high population levels
Use competitive varieties
Weed Control
Mechanical weed control
Pre-irrigate and till prior to planting
Practice frequent cultivation
Use flame-weeders
Employ hand labor (hoe, hoe, hoe)
Weed Control
Herbicidal weed control
These products have been shown to provide some
control (finicky and not consistent)
Herbicidal soaps
Acetic acid
Citric acid
Corn 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, eggs
Ladybugs
aphids, mites, eggs
Minute pirate bug
thrips, eggs
Big-eyed bug
thrips, aphids, eggs
Damsel bug
thrips, aphids, eggs, others
Assassin bug
thrips, eggs
Syrphid fly
thrips, aphids, eggs
Parasitic wasps
aphids, caterpillars, others
Two-spotted stink bug
Colorado potato beetle larvae
Organic Vegetable Production
Approved insecticides:
Bacillus thuringiensis
Cryolite
Herbal preparations
Pyrethrums (natural)
Soaps
Diatomaceous earth
Pheremones
Trapping substances
Spinosyn A&D
Boric acid
Dormant oils
Nematodes
Ryania
Garlic
Insect extracts
Rotenone
Neem oil
Spinosad
Organic Vegetable Production
Prohibited insecticides:
Chlorinated hydrocarbons
Methyl bromide
Moth balls
Organophosphates
Pyrethroids (synthetic)
Carbamates
Nicotine
Methyl sulfoxide
Dimethyl sulfoxide
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
Dormant oils
Hydrogen peroxide
Soil pasteurization
Copper hydroxide
Lime sulfur
Tree waxes/seals
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