Editor's note: This interview was originally published in Greenhouse Management's November 2019 issue. Larry Smart is a member of the Hemp Grower editorial advisory board.
Cornell University professor Larry Smart researches hemp breeding and genetics. From his perspective, it’s the type of research needed to enable hemp growers to succeed now that the crop is legal again in the United States.
Greenhouse Management: A hemp seed bank is coming to Cornell. What is the impetus for the seed bank and what purpose do you think it will hold?
Larry Smart: That will be established by the USDA Ag Research Service and based at Cornell AgriTech. We have two cooperative units of the USDA here on campus and [will have] a germplasm specialist once we hire one. It’s a critical need in the industry because there are no public available germplasm resources that have characterized and developed as we have for every other crop species. As plant breeders look to improve crops, they look for genetic diversity for lines that contain genes for pest and disease resistance, for novel color or shape or any other ideal trait. Every other crop has a free and public resource available to the public, but that resource for hemp was destroyed in the 1970s when hemp was put on the controlled substance list. The hope is to restore that germplasm collection so that hemp breeders have resources available.
GM: In the two-plus years you’ve been doing hemp research, what are some of the things you’ve learned about it?
LS: This crop is particularly fickle in its decisions to flower and what sex it should flower. There are a lot of environmental controls over flowering in hemp, which makes it a little bit tricky to work with, but we’d also like to develop a better understanding of the genetic controls. The thing that is most surprising to me is how unrestrained the industry is at selling products of very poor quality on the side of seeds and cultivars. And that’s because of pure greed, and they are willing to sell seeds to farmers that have not been tested at all. I think if that were to be done commercially in the field corn market, for instance, those companies would be put out of business. If states declared that the only seed that could be sold was certified seed, that situation would change virtually overnight, although there would be very little certified seed available.
GM: How do you approach designing hemp trials?
LS: We’ve done three years of trials for grain and fiber cultivars. This year, we’re testing 37 different cultivars and because they grow quite differently and have different flowering times, we’ve separated them out based on maturity date and height. We’re now in our second season of growing CBD hemp varieties. These days, we’re trying to learn how to propagate things from cuttings even after they’ve gone to flower. And both indoors and outdoors, we’ve learned that hemp is very nutrient-demanding, so just maintaining plants in the greenhouse compared to a willow plant, for example, hemp in the greenhouse requires extremely regular fertilization in order to get the optimal growth.