The Practicality of Diploid Potatoes in North America

Potatoes from Cultivariables 2018 wide diploid TPS mix

The domesticated potato (Solanum tuberosum) is divided into two major groups based on the number of sets of chromosomes: tetraploids, with four sets of chromosomes, and diploids, with two sets of chromosomes.  The common potato of commerce is tetraploid.  There are also hundreds, if not thousands, of varieties of diploid potatoes, but they are mostly […]

Ken Aslet Mashua (Tropaeolum tuberosum) Tests Positive for Viruses PVS and PVY

Tubers of the mashua (Tropaeolum tuberosum) variety 'Ken Aslet'

Ken Aslet is the most common and popular variety of mashua, although it has traditionally been sold as an ornamental rather than an edible.  It has never looked quite right to me, but it tested negative for the most common viruses that infect mashua in the United States.  I recently tested plants more widely out […]

Fine Tuning Germination of Older True Potato Seeds

I start thousands of true potato seeds every year.  You would think that I would be an expert by now, but my results suggest otherwise.  One of the biggest problem areas for me is starting older TPS.  I grow a lot of genebank accessions that are often decades old and they just don’t germinate as […]

‘Purple Star’ Potato Virus Cleanup Part 1: Initial Testing

Tubers of the potato variety 'Purple Star'

This is the first of a series of short videos that will document the process of eliminating viruses from the ‘Purple Star’ potato variety.  Purple Star was selected by Nathan Pierce of the Kenosha Potato Project in 2016 and has since shown the usual signs of running out due to virus burden.  In this video, […]

Tomato Spotted Wilt Virus Infects Yacon (Smallanthus sonchifolius)

I noticed some subtle but consistent leaf malformation in some yacon that I am propagating this year.  (This is not a named or publicly available variety – I use it for breeding.)  I wasn’t sure if this was an intrinsic trait or externally caused, but I don’t remember seeing this before, so I decided to […]

FAQ: True Potato Seed for the Apocalypse

Periodically, I get lots of questions about true potato seeds as an insurance policy against some sort of failure of the agricultural or food delivery system.  The reasoning is straightforward enough: potato tubers don’t keep indefinitely and they take up a lot of space.  True potato seeds last much longer and require very little space.  […]

The Absolute Beginner’s Guide to True Potato Seed (TPS)

Potatoes from Cultivariables 2018 wide diploid TPS mix

There is a lot of information on this website about growing potatoes from true potato seed, but I often hear from people who are interested but who don’t have the time to read all of that material.  If you have heard about TPS and are wondering if it is something that you would enjoy trying […]