Catimor vs. Sarchimor

One parent apart

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Both groups began at the same Portuguese rust research centre in 1967, with the same aim: a plant that resisted leaf rust and stayed small enough to plant densely. The resistance came from the Timor Hybrid, a natural cross of arabica and robusta. The small stature came from a compact mutation of Bourbon.

For Catimor that mutation was Caturra, found in Brazil. For Sarchimor it was Villa Sarchi, found in Costa Rica. The two compact parents are close relatives of each other, so there was never a strong reason to expect the groups to differ greatly, and the catalogue does not claim that they do.

How to read the counts in the table

CoffeeHQ explanation

The table counts the catalogue's entries in each group by category. It shows quality ratings in the Catimor group running from good down to very low, and in the Sarchimor group from very good down to low. It shows rust ratings that are far from uniformly high in either group.

Two cautions apply. The entries are the varieties whose breeders supplied data, a few dozen plants, and are not a sample of what is grown. And a count of categories is not a measurement of the parents: nothing in it shows that Villa Sarchi gives a better cup than Caturra. It shows that a group name predicts very little.

The resistance both were bred for is no longer a given

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In the Catimor group

The catalogue records Costa Rica 95 as confirmed susceptible to leaf rust in Costa Rica, and Lempira and IHCAFE 90 as confirmed susceptible in Honduras.

In the Sarchimor group

The table counts the ratings as the catalogue held them when read. Parainema is among the entries still rated highly resistant; Marsellesa, Obatá and IAPAR 59 are rated at intermediate resistance.

For both

The catalogue reports that most experts expect most existing rust-resistant varieties to lose their resistance in the near to medium term, because most of the available varieties got it from the one shared parent. It adds that a breakdown confirmed in one country does not mean resistance is broken everywhere.

One difference that does show up: nematodes

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Several Sarchimor selections are recorded as resistant to root-knot nematodes, among them Parainema, Cuscatleco and IAPAR 59. Most arabica is not, and the table shows how the Catimor entries are rated. Where nematodes are the problem in the soil, that matters more to a grower than anything else in the table.

The catalogue words these carefully, entry by entry. Parainema is resistant to some species of one nematode genus and not to another. It is a property of particular selections, and should not be read as a property of the group.

What breeders did with each afterwards

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Catimor lines became the mother plants of Kenya's Ruiru 11. A Sarchimor line, T5296, which was never recommended to farmers because it is not stable from one generation to the next, became a parent of the first-generation hybrids Centroamericano, Milenio and Mundo Maya. Another Sarchimor, Marsellesa, is a parent of Starmaya.

Both groups are therefore better thought of as a stage in breeding than as its result. The varieties now being released often have one of them as a parent and an Ethiopian plant as the other.

What to do next

• Catimor — The group's members, one line selected three times, and the Colombian branch.
• Sarchimor — The group's members, and the unstable line that breeders kept using.
• Timor Hybrid — The parent both groups share, and the drawing of how its resistance was passed on.
• F1 hybrids — The next step, which uses lines from these groups as parents.