Purple Sprouting Broccoli
|Title||Purple Sprouting Broccoli: Breeding Cold-hardy, Prolific Varieties for Northwest Growers|
|Breeding Goal(s)||An open-pollinated sprouting broccoli variety adapted to organic farming conditions that is cold-hardy and has flavorful, consistent, 4-5 inch heads on highly productive shoots with tender stems.|
Blue Fox Farm
OSA is working to breed a cold-hardy purple sprouting broccoli variety with prolific shoots of florets. This ancestor of our modern crop is a biennial (two-year cycles for seed production) that requires exposure to winter’s cold temperatures to form the beautiful and tasty purple florets that appear from early to mid-spring. In contrast to modern heading broccoli, purple sprouting broccoli produces many smaller shoots with small “broccoli heads” or florets. This crop is a springtime staple for market farmers and gardeners in mild maritime regions of the UK where temperatures don’t usually dip below 20°F (-6°C) in the winter. A small number of adventurous producers have been growing the crop in a range of maritime climates of the Northwest and British Columbia for a number of years. However, the purple sprouting broccoli varieties that are commonly available to Northwest growers are too sensitive to cold temperatures that can dip to 14°F (-9°C) or they have sprouts that are inconsistent in their length and size of the florets.
Breeding Needs and Goals
Winter fields in the Northwest generally offer little to eat. OSA’s variety trial and breeding work focused on winter season extension is changing that, including the progress we’re making in purple sprouting broccoli. The breeding goals of this project include producing a crop that reliably overwinters in the region, and that has flavorful, consistent, and four to five inch heads on highly productive shoots with tender stems. Additionally, OSA aims for this new purple sprouting broccoli variety to meet the needs of growers in the Pacific Northwest by giving them a market niche advantage.
Breeding Methods and Timeline
OSA began this breeding program by first conducting a trial of a dozen purple and white sprouting broccoli varieties. Eight of these were open-pollinated varieties and four were hybrids. This trial was planted in Port Townsend, Washington, in the mid-summer of 2010 and grown through the cold winter of 2010 and 2011. Temperatures got down to 14°F (-9°C) during several of these nights. We evaluated the varieties throughout the winter for frost damage. Several varieties were damaged to the point where plants died or where the damage severely reduced the yield of sprouts in spring.
Three of the best varieties in the trial – those with a high survival rate – were open-pollinated varieties, two of which also had large purple shoots. We decided to allow 20 of the best plants of each of these two varieties to openly pollinate and harvested seed individually from this cross of these forty plants. These forty packets of seed (each representing a breeding “family”) were planted in identical plots in the summer of 2012 in Port Townsend and Ashland, Oregon. Each location has 40 families, 30 plants in each, from this cross that are currently growing.
While this past winter was mild with no losses due to cold, we saw lots of differences in plant height, the size and yield of the sprouts, and the overall health of some families over others. We selected the best 10 to 20% of the families and allowed them to cross this summer for the next step in the breeding process.
OSA staff had the pleasure of evaluating and tasting our purple sprouting broccoli at the Port Townsend breeding location (Midori Farm) in March of 2013 and 2015. Already the broccoli is extremely delicious – tender and sweet. We plan to release a finished variety in the coming years.
This project is a collaboration with Organically Grown Company, the largest all-organic produce distributor in the Pacific Northwest. Organically Grown Company is investing in the project to expand access to regionally grown, organic produce. They see developing organic purple sprouting broccoli in the Northwest as a valuable research opportunity, and its potential to transgress the farmer’s market niche to a mainstream crop for Northwest growers. This project exemplifies the role our food industry partners can play in ensuring a secure organic seed future for the growers they rely on and the customers they serve.
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