CCFB News» November 2018

Global acreage of industrial hemp remains low, and farmers often have a hard time finding pesticides, which makes variety selection crucial. (Photo courtesy of Stephen Patton, University of Kentucky Agricultural Communications Services)

Illinois farmers await state rules to grow industrial hemp. However, those rules won’t tackle marketing challenges and agronomic unknowns. Currently, the federal government classifies industrial hemp as a controlled substance under the scope of the U.S. Drug Enforcement Administration. The 2014 farm bill authorized hemp research by land grant universities and state agriculture departments.

Illinois starts hemp field trials 

This year, Illinois embarked on its first industrial hemp field trials lead by Win Phippen, a professor of plant breeding and genetics at Western Illinois University (WIU), and two cooperating farmers in Warren and Mason counties. Both Illinois farmers grew hemp to harvest the leaves for cannabidiol or CBD oil. That required 5-foot spacing between plants and 5 feet between rows, Phippen said. One farmer planted 1,200 plants, and the other planted less than 100. The crop was either seeded or transplanted as 4- to 5-inch seedlings when soil temperatures reached 55 degrees in mid to late May. By late August, the plants grew to 5 to 6 feet in height.        

Phippen and the farmers were surprised by weather problems. Because the plants were topped to increase leaf production, they became bushy, top-heavy and susceptible to wind damage. One crop was protected from wind. The other wasn’t and was destroyed when high winds knocked down the plants. “Nowhere in the rule book does it say, ‘Watch out for wind,’” Phippen said. For soil fertility, the farmers incorporated 100 pounds of nitrogen per acre preplant, but Phippen said Illinois will need fertility studies for industrial hemp.

After the two hemp crops were established, weeds couldn’t compete and weren’t a problem. The 5-foot grid spacing also allowed mowing to control weeds. Neither grower experienced much insect damage, but Phippen speculated insects may become a problem with increased hemp acres.

With only two certified labs in Illinois, Phippen anticipated a bottleneck if large numbers of farmers growing industrial hemp need frequent test results from two labs that also provide testing services for the state’s medicinal marijuana sector.

Illinois’ potential industrial hemp crop is generating a lot of interest. Phippen said he’s received calls from farmers who want to do everything from growing a crop to raising transplant plugs, and from drying harvested crops to extracting oil.

He frequently gets calls from individuals wanting to buy harvested hemp.

Industrial Hemp Basics

• Farmers planted only 300,000 acres worldwide.
• Illinois farmers should decide what part – flower, seed or biomass – they plan to harvest before planting hemp.
• Hemp produces optimal yields in well-drained, silt loam soil.
• Kentucky farmers use conventional tillage and a drill to seed hemp at a quarter inch depth.
• Some farmers have used no-till, but the shallow depth makes that more difficult.
• Hemp seed size varies from 10,000 to 50,000 per pound.
• General hemp seedling vigor is very poor.
• A heavy rain that crusts soil will destroy a crop and standing water for 48 hours will drown it.
• Hemp grown for CBD is labor-intensive and requires extra attention, especially before harvest. Starting in late August, farmers must frequently monitor the leaves’ THC (Tetrahydrocannabinol) levels to ensure those don’t exceed regulated thresholds.

Hemp leaf harvest requires hand labor. The stems, measuring 3 to 4 inches thick, are cut with a sickle bar, then hauled to a location where the stalks are hung upside down and dried. One farmer used a pole building with fans and louvers to provide sufficient aeration. Air movement is most important in a cool and dark space.

This article is a compilation of articles written by Kay Shipman, FarmWeek.