Garlic Production Lecture and Slide Show

David Stern, manager of Rose Valley Farm in Rose, NY and director of the Garlic Seed Foundation, offered a pre-conference workshop on garlic production at no charge. He covered all aspects of garlic production from selecting seed to soil fertility, weed control, harvest and post-harvest handling. After the slide show, he demonstrated a fast, simple way to make handsome "string braids" of hardneck-garlic, which can be difficult to braid in the usual manner. Following are a few tips that he shared, which may save garlic growers some time and/or headaches.

Be sure the plant the clove right-side up. Planting upside-down can cost 30% of yield. Remove the emerging scape ("seed" stalk) on hardneck garlic, as letting it mature can also cost 30% of yield. Cut or snap off on a warm dry day so the wound heals fast.

Garlic is quite hardy, but it has a few distinct temperature limits and daylength responses that are good to know. Fall is the best time to plant garlic. However, you can plant in early spring if you first vernalize the seed garlic for 40 days at 40°F (refrigerator is good). Be sure to keep a good mulch on the soil around the growing crop. If the soil reaches 93°F, garlic stops growing and goes into senescence. The garlic top ceases to grow at the summer solstice, but bulb growth continues for some time thereafter. To determine if hardneck garlic is ready to harvest, dig up a plant or two, and cut the bulb in half cross-wise. If there are small gaps between the cloves and the center stalk, it is ready. If the cloves still fit tightly, the bulbs are still growing. For long term storage, the garlic needs to be cured in a warm dry place for 10-14 days. Be sure it does not get hotter than 121°F, as this kills the cloves and causes "waxy breakdown." Cured garlic keeps best at 32°F and about 65% humidity. Temperature fluctuations may cause roots to begin to grow out the bottom (harmless), but garlic does not freeze until temperatures drop to 21°F.

David showed us many ways to grow, harvest and market garlic. In addition to the main crop of bulbs grown from large individual cloves, the scapes produced in late spring sell well if they are cut when young and tender. An acre of garlic may yield 300-500 lb of scapes. David also plants small garlic bulbs whole to produce garlic greens, which can be cut when they reach 10 inches height, and will give three cuttings. Or, separated cloves or bulbils from mature scapes can be planted in a furrow, grown to 8-10 inches, then dug as garlic scallions. Cloves/bulbils can be planted in July for fall harvest, or in fall for spring harvest.

For more information on garlic production or on the Garlic Seed Foundation, contact David Stern, Rose Valley Farm, Rose, NY 14542-0419, tel. 315-587-9787, web site www.garlicseedfoundation.info.

Keynote Address: Iowa's Transition to Organic Farming: How it Happened

Dr. Kathleen Delate, who has held an extension and research position in the Departments of Horticulture and Agronomy at Iowa State University (ISU) since 1997, discussed the rapid growth in organic farming in her state, and research results comparing organic and conventional systems. About 500 farms in Iowa now use organic practices on a total of 120,000 acres to grow corn, soybeans, wheat, barley, oats and forages. Some producers are also growing organic vegetables, berries, apples, grapes and medicinal herbs. There are some 40 Community Supported Agriculture farms (CSAs) in Iowa.

Low commodity prices and concerns over nitrate contamination of ground water stimulated interest in organic farming among Iowa farmers. Farmers ' focus groups that met in 1998 to identify organic growers' research needs have guided Kathleen's research agenda. Topics include organic vs. conventional rotations, soil amendments and cover crops for organic vegetables, tillage, certain pest and disease problems, organic fruit production in southwest Iowa, edamame soybean varieties, and food quality comparisons. By 2001, the ISU organic program had raised over $900,000 to conduct long term research trials to answer these questions.

Iowa's organic certification program requires a good crop rotation that includes a soil building hay or cover crop, to enhance soil organic matter, balance nutrient demands, and break pest/weed life cycles. Kathleen has been comparing a conventional two-year rotation of corn-soybean with organically managed rotations of corn-soybean, corn-soybean-oats/alfalfa (3 year) and corn-soybean-oats/alfalfa-alfalfa (4 year). Over a five-year period, corn and soybean grain yields from the 4-year organic rotation have equaled conventional yields, while the 2-year organic rotation yields were only slightly lower. (Kathleen noted that this result was a great source of irritation for one Dennis Avery, who called her up to demand how she could have come up with such a result!) More significantly, the longer organic rotations realized net returns of $290 per acre, compared to just $73 per acre for conventional corn-soy rotation.

The organic system also improved soil quality, with increased aggregate stability (a measure of soil tilth), lower nitrate levels (less leaching to groundwater), higher organic matter, and a 128% increase in soil microbial biomass. Other findings include fewer soybean cyst nematodes in the organic system, less weed pressure in corn after oats/alfalfa, and avoidance of seedcorn maggot by waiting until the soil warms up to plant corn. For weed management, Kathleen said, "we use a lot of steel," and described an integrated strategy of winter rye cover crops, rotary hoeing before emergence, timely cultivation, narrow row spacing, high plant populations, and competitive crop varieties.

Most of Iowa's organic farms have livestock and use the manure to recycle nutrients, and are just beginning to use cover crops as well. Horticultural producers use cover crops but not compost, relying on Iowa's rich, dark soils to provide nutrients. Yet Kathleen's experiments have shown a 20% broccoli yield increase from using compost, and she strongly recommended compost in Virginia, where native soil fertility is often lower.

Kathleen even reported success with organic apples and grapes in Iowa. She strongly recommended scab-resistant apple varieties such as 'Jonafree', 'Redfree' and 'Liberty.' and noted that the new clay-based pest control 'Surround' effectively controls codling moth and apple maggot. She suggested regionally-adapted grape varieties, rather than drought-adapted French or California varieties which succumb to disease in the more humid climates of Iowa and Virginia.

Finally, Kathleen noted that many of Iowa's successes with transition to organic can be translated or adapted to other regions. For more information, contact Kathleen Delate, Assistant Professor, 106 Horticulture Hall, Iowa State University, Ames, IA 50011, tel. 515-294-7069, e-mail kdelate@iastate.edu.