Winter squash: extending the season and expanding the uses

Winter squash: extending the season and expanding the uses

Summary

Winter squash is a delicious and nutritious vegetable. PNW retail winter squash sales peak in October/November and decline to April. Butternut makes up 1/3 of sales, spaghetti squash 17%, acorn and delicata at 12% each, and a diversity of other types filling in the remaining 25%.  Regional wholesale squash farmers supply much of the organic winter squash in October and November but not thereafter, as farmers have not been successful in storing squash into the winter. Half of the winter squash sold in December, and almost all of it sold from January through April, is imported from California and Mexico. Consumers shopping in natural foods stores increasingly prefer local sources, so there is a local organic squash sales opportunity from December through April.  Project distributors/retailers sell more than 200,000 pounds of squash per month in October and November, with sales dropping 80% by April. If local farmers picked up an additional 25% of the December sales, plus 75% of sales in January-April, they would sell an additional 300,000 pounds (8500 35-pound boxes). If sales volume also increased 20% from December-April, they would sell another 1700 boxes. At approximately $25/box, farmers selling to these markets would collectively gross an additional $250,000 each winter. These farmers wholesale to other markets that would purchase more local squash if available.

Smaller farms are increasingly focusing on winter marketing through CSAs, farmers markets, and restaurants as demand for year-round local produce increases. These farmers struggle to grow crops for sale in January through March. They have trialed varieties and experimented with storage to extend the squash season with little success as they don’t have reliable variety and storage information.

Identifying high yielding varieties with excellent winter culinary quality that are reliably long storing under fluctuating farm conditions is a research priority for these two farmer groups.

Objective 1: Identify winter squash varieties that are profitable to grow and store for marketing from December to March in western Oregon

Growing season 2016: Winter squash varieties that in preliminary trials yielded well in western Oregon and stored well under fluctuating barn conditions were formally evaluated in 3 on-farm randomized trials (3 reps) and two research station replicated experiments (irrigated and dryland). One of the on-farm trials was not harvested as plants in two of three blocks were killed by symphylans.  In all other experiments, squash were harvested when physiologically ready and total yield, average fruit weight, and range of fruit weight were quantified. Subsamples of squash from all experiments  were stored in both a closed barn bay (maintained above 40F) and an open barn bay (squash moved into closed bay maintained above 30F when open bay temperatures fall below 30F). Squash was evaluated for percent rotten and quality (dry matter, Brix, and sensory attributes) in mid-December (and will be evaluated again in late January, and mid March). Production and storage data analysis is underway. Additional farmers trialled varieties informally on their farms.

Varieties grown in all experiments:

Kabocha family (C. maxima): Sweet Mama (green F1 AAS winner), Winter Sweet (gray F1), Blue Kuri (gray OP), Shokichi Shiro (mini gray F1) kabochas; Crown (gray heirloom OP); Silver Bell (gray to pink heirloom OP); Red Kuri (red OP); Gold Nugget (orange OP, AAS winner); Georgia Candy Roaster (pink heirloom OP); Sibley (blue heirloom OP). Acorn family (C. pepo): Gill’s Golden Pippin acorn (Oregon heirloom orange OP), Zeppelin delicata (Oregon-selected OP), Small Wonder spaghetti (F1). Butternut family (C. moschata): Betternut butternut (F1), JWS 6823 butternut (F1), Early Remix butternut (Oregon-selected OP), Black Futsu (Japanese heirloom OP); C. maxima x C. moschata cross: Tetsukabuto (F1).  OP = open pollinated, less expensive seed, seed can be saved; F1 = hybrid, more expensive seed, seed cannot be saved.

Objective 2: Describe taste (flavor and texture), marketing window (when they taste best) and best culinary uses (recipes) for varieties in Objective 1.

Fall/winter 2016-2017: Two fruit of each variety stored at OSU were evaluated by the chef for sensory quality in December; this will be repeated in late January and mid-March using a protocol developed and tested at OSU in 2015.

Objectives/Performance Targets

Objective 1: Identify winter squash varieties that are profitable to grow and store for marketing from December to March in western Oregon

Objective 2: Describe taste (flavor and texture), marketing window (when they taste best) and best culinary uses (recipes) for varieties in Objective 1.

Objective 3: Develop marketing materials for varieties identified in Objectives 1 and 2. See Outreach Materials section below.

Objective 4: Engage farmers (and distributors, retailers) with results of Objectives 1-3 and other information on squash varieties, production, storage, sensory quality, and culinary uses. 

Accomplishments/Milestones

Objective 1: Identify winter squash varieties that are profitable to grow and store for marketing from December to March in western Oregon

Growing season 2016: Winter squash varieties that in preliminary trials yielded well in western Oregon and stored well under fluctuating barn conditions were formally evaluated in 3 on-farm randomized trials (3 reps) and two research station replicated experiments (irrigated and dryland). One of the on-farm trials was not harvested as plants in two of three blocks were killed by symphylans.  In all other experiments, squash were harvested when physiologically ready and total yield, average fruit weight, and range of fruit weight were quantified. Subsamples of squash from all experiments  were stored in both a closed barn bay (maintained above 40F) and an open barn bay (squash moved into closed bay maintained above 30F when open bay temperatures fall below 30F). Squash was evaluated for percent rotten and quality (dry matter, Brix, and sensory attributes) in mid-December (and will be evaluated again in late January, and mid March). Production and storage data analysis is underway. Additional farmers trialled varieties informally on their farms.

Varieties grown in all experiments:

Kabocha family (C. maxima): Sweet Mama (green F1 AAS winner), Winter Sweet (gray F1), Blue Kuri (gray OP), Shokichi Shiro (mini gray F1) kabochas; Crown (gray heirloom OP); Silver Bell (gray to pink heirloom OP); Red Kuri (red OP); Gold Nugget (orange OP, AAS winner); Georgia Candy Roaster (pink heirloom OP); Sibley (blue heirloom OP). Acorn family (C. pepo): Gill’s Golden Pippin acorn (Oregon heirloom orange OP), Zeppelin delicata (Oregon-selected OP), Small Wonder spaghetti (F1). Butternut family (C. moschata): Betternut butternut (F1), JWS 6823 butternut (F1), Early Remix butternut (Oregon-selected OP), Black Futsu (Japanese heirloom OP); C. maxima x C. moschata cross: Tetsukabuto (F1).  OP = open pollinated, less expensive seed, seed can be saved; F1 = hybrid, more expensive seed, seed cannot be saved.

Objective 2: Describe taste (flavor and texture), marketing window (when they taste best) and best culinary uses (recipes) for varieties in Objective 1.

Fall/winter 2016-2017: Two fruit of each variety stored at OSU were evaluated by the chef for sensory quality in December; this will be repeated in late January and mid-March using a protocol developed and tested at OSU in 2015.

Impacts and Contributions/Outcomes

As this project has just started there are as yet few documented impacts. Farmers are growing and selling these varieties and storing them into deep winter (December through March). Farmer/buyer workshop and outreach events are planned for early 2017.