There are no changes to the abstract.
There are no changes to objectives.
- To conduct a variety trial of 18 open-pollinated (mostly heirloom) Cucurbita moschata squash, our breeding seed stock, 1 hybrid butternut squash, and 1 open-pollinated commercial butternut squash under organic conditions and without any row cover, fungicides or pesticides, even those that are organically approved, in order to identify varieties particularly suited to our region and for possible seed stock.
- To identify or develop by traditional breeding methods Cucurbita moschata seed stock that is productive, has good flavor, is easily marketable, and stores well. We are looking particularly for a variety or varieties that are heat- and drought-resistant, insect-resistant, and disease-resistant. We have had particular problems in hot, dry seasons like 2016 and with cucumber beetles, squash bugs (Coreidae), and downy mildew. Other farmers in the region are also affected by squash vine borers, powdery mildew, and bacterial wilt.
- To conduct breeding trial of F1 cross of San Jose Club Squash and Waltham Butternut, evaluating and selecting for productivity, overall resistance, taste, marketability/appearance, and storage ability. We will continue selecting for butternut shape and size, as long as also correlates with other selection factors.
- To share results as part of community day and identify interested parties that may be able to partner with us in the future.
- To continue to evaluate and to save seed from best performers from 2017 study, selecting for productivity, overall resistance, taste, marketability/appearance, and storage ability.
- To conduct breeding trial of F2 cross of San Jose Club Squash and Waltham Butternut, evaluating and selecting for productivity, overall resistance, taste, marketability/appearance, and storage ability. We will continue selecting for butternut shape and size, as long as also correlates with other selection factors.
- To conduct breeding trial of F1 cross of Carrizo and VA Select Waltham Butternut, evaluating and selecting for productivity, overall resistance, taste, marketability/appearance, and storage ability. We will continue selecting for butternut shape and size, as long as also correlates with other selection factors.
- To host a field day to teach about hand-pollination and traditional plant breeding.
- To host a community day to share final results of two-year study as well as seed stock from best performing specimens.
Our breeding project (San JosexWaltham) is more productive than other squash we have grown.
- Weather: the 2017 season was relatively cool and wet. Squash were transplanted the first week of May, and we began harvesting the first week of August, through frost in late October, with the main harvest coming the third week of August. It rained at some point in the day more than half of the days (53) during the 105-day growing period. There were only 14 days at 90 degrees or above, most of them coming in mid-to mid- late July. Average high temperature was 84. (In other words, it was not hot or dry this season. Two values that we would like to develop resistance for.)
- All varieties were affected by Downy Mildew. We had early infection this season: all varieties had leaf lesions by the end of May (typically we see in early to mid-June). All varieties grew past infection to still produce crop. Varieties most affected based on initial loss were: Segualca (25%), Noob Taub (10%), Cuban Neck Pumpkin (10%), and Greek Sweet Red (10%). A low average weight (Nutterbutter and JMS6823), reduced storage ability (Nutterbutter, JMS6823, and Segualca), and bland flavor (Carrizo, San Jose Mountain Club Squash, Thai Kang Kob, and South Anna) also suggest significant stress either because of Downy Mildew or humidity or heat or a combination of all of the above.
- We did not have extensive insect pressure this season. Although spotted cucumber beetles (early in the season) and squash bugs (Coreidae) (late in the season) were present, they were not present in significant enough numbers for us to consider them a factor in overall production.
- We created a “Resistance Value” based on # of fruit, %loss, taste, and storage. Although it is not completely comprehensive, we do believe that it accurately reflects heat, drought, insect, and disease resistance on our farm. To calculate, we divided # of fruit/plant average by 3 (our minimum goal for production) then multiplied by 100 to give a 100s value number and then multiplied that number by .4 (as we decided that overall production was the most important value based on discussion with farmers and amongst ourselves). We gave taste and storage value equal weight. We calculated the taste value by multiplying taste number first by 10 to give a 100s value number and then multiplied that number by .25. We calculated storage value by assigning 0, 25, 50, 75, or 100 to a given variety based on how long it stored and then multiplied it by .25. Finally, we subtracted percentage loss from 100 and multiplied it by 0.1. Because most of our plants typically survive stress but justproduce poorer quality fruits, we gave %loss the lowest percentage value (10%). If percentage loss numbers were more significant, we would increase this percentage.
- Based on this resistance value, the best performing varieties were: San JosexWaltham cross, Upper Ground Sweet Potato 2017, Upper Ground Sweet Potato 2016, Tahitian Butternut, and Ayote (in that order). Note that none of these varieties produced our minimum of 3 fruit/plant.
- Also, note that our goal is a butternut-shaped fruit. None of the best performing varieties are a strictly butternut-shaped fruit. San JosexWaltham cross produces a butternut shape but also produces a pumpkin-type and a bell. We hope to be able to select for the butternut shape. Tahitian Butternut produces a very long neck butternut that is too large for many of our CSA members. Tahitian Butternut could likely also be selected for a shorter neck. The other three (Upper Ground Sweet Potato 2016 and 2017 and Ayote) do not appear to have butternut genetics.
- Another one of our goal is a 3-4 lb. fruit. That is the size that our CSA members have been the happiest with. All of our best performing squash except for Tahitian Butternut are too large in their current form. However, we did not separate out genetic lines of San JosexWaltham cross when weighing. It is likely that the butternut-shape is less heavy than other shapes. We may be able to select for a smaller San Jose cross just by selecting for butternut shape.
- Taste is obviously a subjective value. It includes both taste and texture as compared to butternut squash. These values reflect the opinion of 17 of our CSA members. Taste tests were performed on 11/4/17. Taste of some varieties can improve in storage. At this point, all squash had been in storage for at least 2 months. A note: our CSA members loved Upper Ground Sweet Potato 2016 (seed selected on our farm). They gave it an “11”. If you are not worried about other parameters such as size and shape, it is a great squash! It would be particularly good for holiday dishes such as pies.
Educational & Outreach Activities
On November 12, we hosted a community day, which was a field day/presentation/demonstration day for area farmers and agricultural professionals. We also shared with them our “Evaluating Winter Squash” document which details our project, terminology necessary for understanding the project, variety descriptions and pictures. They also received a copy of our preliminary research results. Together, we made plans for two events in 2018 (a workshop in June on hand-pollination and another presentation in October to share final results and seeds) as well as on-going communication with this group.
plant breeding, pollination, variety selection, stress-factors
Already through the project, we have been able to help two other local farmers change the way they had been growing winter squash (they were having no success). We have also been able to make changes in the way we grow winter squash as we begin to understand how all of the factors of our research interact. Through our community day, we were able to attract two new collaborators: Annette Wszelaki (UT Extension Agent) and Bonnie Ownley (UT Ag Professor). We will continue to share our research with them and have them share ideas and commentary with us over the course of the season. Dr. Ownley is interested in how this research may inform research she is doing on butternut squash and organic biological/fungal applications.