Monday, February 24, 2014

Cold Winter, Spring Plantings, Bayesian Inversion

Winter may be going out with a bang, but that hasn't stopped us from our first spring planting. The next seven days are all forecast to be more than 20 degrees below average, and Thursday Feb 27 is forecast to have a record low of -20 F. This will easily be the coldest winter since 1979 in Southern Wisconsin, and could well have been the coldest winter since 1935 or even 1901. I'm not sure how much of a "heat island" effect the city of Madison has - I know the temperatures at my house would qualify as the coldest winter since 1901 in Madison, but we've averaged about 1.5 degrees lower than the official site in Madison. winter winds down we've germinated our first seeds - Datil peppers which is an exceptionally hot pepper - a variety  of the species Capsicum chinense From the reading I've done online, Capsicum Chinense varieties of hot peppers have an exceptionally long germination periods (12-25 days). Thus it was with some surprise that I noted more than 25% of the seeds had germinated on day 5. An additional 25% germinated on day 6 - I was going to be happy with 25% total germination in 25 days! For anyone interested, I used the "wet paper towel in a baggie" method and kept the baggie behind my wood stove laying on the bricks. I did go to the trouble of finding a place where the temperature varied between 65 and 90 degrees - most of the day it is between 75 and 85 on the bricks, and it cools down below 70 for only a few hours in the early mornings each day.

I've now transplanted all the seeds into wet soil, and they will remain on the bricks, covered by saran wrap until the first shoots break the soil. Then I will move them under a grow light where they will remain until late May.

Since we bought many of our seeds from a place with mixed reputation this year, I might try the paper towel method on a wide variety of seeds just to see whether I need to re-order any seeds. This is where a Bayesian Inversion spreadsheet would come in handy! If I only need to be 95% sure that 35% or more of the seeds will germinate, than I can do a trial on just two seeds - if they both germinate, I can be 95% sure that 36.8% or more of the seeds will germinate. Likewise if 3 of 4 germinate I can be similarly confident of a 34%+ germination rate, and even 3 of 5 gives me 95% confidence that 27%+ will germinate.

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