Chris Konieczka Extension Educator, Local Food Systems and Small Farms Livingston/McLean/Woodford Unit cmkonie@illinois.edu
When to Consider these? Pre-harvest Harvest Wash/Pack Storage Delivery
Impacted by Temperature Moisture Mechanical Injury Disease Produce quality can only be maintained post-harvest
Soil Quality Seed Selection Organization and management Worker Training
Seed Selection Make varieties fit harvest times Disease resistance Storage quality Organization and Management Harvest planning by date and yield Irrigation schedule Insects row cover, spray, etc. Disease plastic mulch, staking, pruning Weeds cultivation plan, tillage, etc.
Worker Training Use of tools Sanitation Quality standards Assign specific harvest duties
Timing/weather Know signs of crop maturity Avoid mechanical injury Wash/storage areas ready
Timing and Weather Harvest wet crops early morning Other crops need to dry before harvest Maturity based on your market
Wet Crops Lettuce Sweet Corn Brassicas Roots with tops Bulk Harvest Potatoes Onions Garlic Dry Crops Squash Melons Cucumbers Beans Tomatoes
Crop Injury Machine harvest can bruise produce Hand harvest = better quality and maturity mgmt. Equipment size and cost should match production scale
Tall crops in two rows Mark bed progress clearly Field sort where possible Scout your fields Is crop intended for storage or market?
Respiration Rate Respiration Drying out Less food value Less sweetness Less dry weight Low Moderate High Very High Extremely High Apple, beet, celery, garlic, melons, onion, potato (mature), sweet potato Cabbage, carrot, cherry, cucumber, head lettuce, peach, pear, pepper, potato (immature)radish, summer squash, tomato Carrot(with tops), cauliflower, leeks, leaf lettuce, raspberry, strawberry Artichoke, broccoli, Brussels sprouts, green onion, kale, okra, snap bean Asparagus, parsley, peas, spinach, sweet corn
Considerations Pack shed design Pre-cooling Equipment Containers Water and sanitation
Pack Shed Design Efficiency Diagram product flow Light/Shade Sufficient, safe water Sanitation Floors/Surfaces Ergonomics
Artichokes (i) Brussels Sprouts (i) Green Onions (i) Asparagus (i) Broccoli (i) Sweet Corn (i) Greens Peas Pre-cooling Remove field heat Lower respiration rate Hydrocooling Cooler/drench/ice
Root Washing Batch Tumbler Barrel Washer Brush Washer Batch Washer Equipment Other Ideas Mesh bags for greens Hands-free wash station Roller tables
Containers Water resistant submersible Sturdy Does not damage product (smooth) Versatile Sanitary Vented Stackable
Irrigation, municipal, well, and surface water tested for microbial activity Sanitation is imperative in every step of the production chain Water Potable water for all usescooling, ice, etc. Sanitizers/Disinfectants can help prevent disease and illness Wash water temp within 10 of produce
Disinfectants and Sanitizers Chlorine Bleach Concentrations vary 50-150 ppm (higher can be harmful) Efficacy reduced by light, temp, soil Monitoring is a necessity Requires rinsing Inexpensive Peroxyacetic acid Low reactivity with organic matter No rinse required Widely applicable Relatively safe 40-80 ppm Tsunami, SaniDate
Disinfectants and Sanitizers Hydrogen Peroxide Concentrations of 0.5% or less can be effective against postharvest fungi Low environmental risk Ozonation More effective than Cl 2 System includes generator and monitoring gauge Dissolved into water $10,000+ to begin
Temperature Humidity Freezing and Chilling injury Ethylene Curing
Remove field heat Lower respiration rate Optimum storage temps vary For growers with limited space ~40 is best Maintain cold chain Temperature Cooling Methods Room Cooling Forced-air Cooling Hydrocooling Water Spray Icing
Low-cost room cooling
Time and temp Effects cumulative in some crops Freezing and Chilling Injury High Sensitivity Basil Cucumbers Eggplants Pumpkins Summer Squash Okra Sweet Potatoes
Most crops store best at high humidity ~95% Prevent moisture loss Monitoring is important Humidity Cool-Moist crops Snap Beans Cucumbers Eggplant Cantaloupe Watermelon Peppers Potatoes Tomatoes, ripe
Natural plant hormone Promotes ripening Can damage other crops in storage Crops vary in level of ethylene production and sensitivity Store separately Ethylene Effects Spotting of lettuce Bitterness in carrots Yellowing of Brassicas Softening of melons Discoloration of sweet potatoes and eggplant Softening of mature green tomatoes Shattering of berries
Improves long term storage of some crops Shade, air circulation, high humidity Take care to avoid damage, cull before storing Curing Alliums 2 wks, trim, store 32, 65% humidity Potatoes 2 wks, store 40-50, 90% humidity Winter Squash 7-10 days at 70, store at 50 and 50-75% humidity
Questions? Visit our websites to find out about other programs and events: Livingston, McLean, Woodford Unit - http://web.extension.illinois.edu/lmw/ Illinois Small Farms - http://web.extension.illinois.edu/smallfarm/ Photo Credits: Google Images