December 08, 2022

Varieties, processing among hemp growing challenges

SYCAMORE, Ill. — As growers prepare for the second year of growing industrial hemp, it is difficult for agronomists to recommend specific varieties for Illinois fields.

“Currently, there are no Illinois bred varieties,” said Phillip Alberti, University of Illinois Extension commercial agriculture educator.

“We’re taking genetics from other places and planting them in an area they were not bred for,” Alberti explained during a presentation at the Introduction to Industrial Hemp meeting organized by the University of Illinois Extension in Sycamore. “We don’t have plants that can fully optimize our growing conditions.”

Varieties that are available to licensed Illinois growers are grown in places such as Colorado, Oregon, the European Union or Canada, Alberti said.

“We’re not sure how they are going to respond here, so we have a lot of work to do to develop breeding programs,” he said.

Both industrial hemp and marijuana are cannabis plants.

“What makes them different is the amount of the THC concentration in them,” Alberti said.

Hemp is primarily dioecious which, means it has separate male and female plants, and that is different from corn and soybean plants that are self-pollinating plants.

“Hemp is photoperiod dependent like soybeans, so the flowering is triggered based on day length,” Alberti said.

Alberti explained there are different types of cannabis plants.

“Sativa plants are bred from more temperate climates, and the plants are taller and have thinner leaves,” he said. “Indica plants are shorter in stature with broader leaves, and they are bred in cooler climates.”

Next Steps

Processing of hemp also is an issue in Illinois.

“Currently, there are no grain or fiber processing plants in the Midwest,” Alberti said. “We are way behind Canada and the European Union that have established companies for processing and manufacturing of hemp, so we are importing hemp products that are used in clothing.”

Illinois farmers can choose to grow hemp for grain, fiber or CBD.

“Growing hemp for grain or fiber uses production systems that most represent Illinois growers because they are similar to row crops,” Alberti said. “Growing for CBD or flower production is more like a specialty crop such as vegetables or cut flowers.”

Hemp that will be harvested for fiber is chopped, baled and sent to a processor. Separating the hemp stalk produces several products.

“The bast fiber is the most valuable portion, and it is used for textiles, building insulation and composites for car doors,” Alberti said. “The woody core or hurd is used for paper.”

“During decortication, which is when the fiber is taken from the hurd, dust is created,” he said. “The dust can be collected, compressed and used as a biofuel.”

Hemp seed oil is produced when the hemp seeds are cold pressed and the oil is extracted.

“It’s high in protein, fatty acids and Omega 3s,” Alberti said. “The hemp seed oil is used as an additive to shakes and smoothies, and you will find it in the health food section of stores.”

Cannabinoids are produced in the flower of un-pollinated hemp plants.

“There are close to over 100 types, most of which we don’t know what they do,” Alberti said. “Cannabinoids bind to the receptors in your body and elicit a response.”

“If the female plants are pollinated, they produce seed and the cannabinoid production shuts down, so that is why the males must be culled in a CBD production operation,” he said.

Consumers are looking for specific tastes or smells with the CBD products they are purchasing.

“The plant produces terpenes and flavonoids, which are the taste and smell compounds,” Alberti said.

Good Start

Alberti encourages farmers to plant hemp in highly productive fields that are well drained with low weed pressure.

“The plant doesn’t like standing in water,” he said. “Early season washouts were devastating for crops in 2019.”

Plant hemp seeds when the soil temperature is higher than 50 degrees, Alberti said, and pay attention to planting depth.

“I saw a 100-acre field get wasted last year because it was planted too deep or before a rain and the soil crusted over so the emergence was terrible,” he said.

Hemp will germinate and emerge quickly with favorable conditions.

“I saw fields up in the first week,” Alberti said. “Once the plants pop out of the ground, it has a slow growth phase where there is a lot more below ground growth than above ground.”

This period, Alberti stressed, is a critical weed control period.

“There are no herbicides labeled for this crop,” he said. “So, you need to have weed control methods like cover crops, tillage or mowing.”

After 30 days, the plant goes into a rapid growth phase accumulating size before it flowers.

“If you are a CBD grower you are out in the fields scouting and culling the male plants from about Aug. 1 to Aug. 20,” Alberti said. “Male plants are resilient and re-rooting is a problem, so you should get the whole plant out of the field.”

Hemp for fiber plants reach maturity about late July, and hemp grown for grain is typically harvested during the end of September, Alberti said.

“CBD hemp is harvested about the end of September or the first week of October,” he said.