Author Archive | bill


Potato: Color Genetics

For many crops, you don’t have to search very far to find a nice summary chart of the major genes involved in economically important traits.  This kind of information makes breeding decisions a lot easier.  Knowledge of the genetics underlying traits allows the breeder to identify varieties that are homozygous for a particular trait and […]

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Potato: A Ploidy Primer

Introduction How Seeds are Formed Domesticated and Wild Potatoes Ploidy Monoploid and Haploid Numbers Haploids Interactions of Ploidy in Crosses Unreduced (2n) Gametes Endosperm Ratio Endosperm Balance Number A Final Note on Probability Determining Ploidy Morphological Evalutation Guard Cell Counts Chromosome Counts This is probably not a finished work yet.  I have been puttering away […]

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Ulluco: 2016 Wrap Up

Unveiling new ulluco varieties is starting to become a little routine.  Oh well, there is really no rut that I would rather be stuck in. I reached a peak of 44 ulluco seedlings this year.  25 of them died, were culled due to obvious disease, or failed to set any tubers.  19 survived to the […]

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About My Potato Breeding Projects

Because we sell excess seed from my potato breeding projects, we get a lot of questions about what my goals are.  Those goals are sometimes hard to articulate because I haven’t thought through them as clearly as I have done for the other plants that I work with.  My work with potatoes goes back before […]

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Yacon plant variety OC-16-1Ux02x08

Yacon: Seedling Progress

Last year, we grew two new yacon varieties from seed and also collected more than 1000 yacon seeds.  This year, after starting seeds in November, we have 132 yacon seedlings.  Each one of those seedlings will be a new variety, a consequence of both yacon’s polyploid nature and the fact that it is an obligate […]

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A large pile of ahipa seeds of the variety Tarija

Ahipa: Getting to the root of beans

Ahipa (Pachyrhizus ahipa) is one of a few varieties of bean that have been bred for their roots, rather than for their seeds (the beans).  It produces a storage root that tops out at about 2 pounds in its native region in Bolivia.  The root is used similarly to yacon: more like a fruit than […]

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Eight ulluco varieties grown from seedlings. The tubers are small. Colors are purple, light green, yellow, orange and purple, dark purple, and lime green

Ulluco: 2015 Mini tuber harvest

We had 27 ulluco seeds germinate in 2015, but they did so over a very long period of time and more than half of them popped up in September, by which time it was growing late to produce tubers.  In addition to short day length, ulluco needs a few months of growth before it is […]

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