New Kenyan coffee varietal

by on August 30, 2011

Last year the Coffee Research Foundation (CRF) in Ruiru, Kenya released a new disease-resistant arabica varietal that has been in development for more than an decade. Named after the highest peak on Mt. Kenya, Batian is resistant to coffee berry disease and coffee leaf rust, the two common fungal diseases affecting coffee in Kenya and much of Africa.

The parentage of Batian is predominantly arabica, and it is closer genetically to the well-regarded SL28 and SL34 varieties than Ruiru 11, the rust-resistant varietal introduced in 1985. Varieties used in the development of Batian include SL4, N39, N30, Hibrido de Timor, Rume Sudan, and K7. They were repeatedly backcrossed with SL28 and SL34. The Hibrido de Timor is the naturally-occurring hybrid of arabica and robusta, and is often used in disease-resistant breeding due to its robusta heritage.

Of course, it is the robusta lurking in the background that tends to lower cup quality. According to the CRF, however, Batian cups far better than Ruiru 11 and even the parental SL varietals. Here’s a slide from a presentation by Dr.  Joseph Kimemia of the CRF (click to enlarge):Should we take that with a grain of salt (so to speak)? A tasting of these four varietals by the guys from Tim Wendelboe at the CRF did find Bastian rising to the top, but the cupping was a little suspect (e.g., poor examples of the SL28, for instance).

Why a new varietal?

Kenyan coffee production has been declining since at least 2001. There are a number of reasons for this, but in recent years part of the problem has been instability in the weather. Drought and heavy rain disrupt flowering and fruiting, and wet conditions also cause an increase in fungal diseases. Thus, a varietal that has more resistance to these diseases is welcomed by farmers.

In the case of Batian, it also matures faster than other varieties — in two years versus three. It is high yield, but Batian’s ability to boost production is in large part due to the fact it can be planted at twice the density of other typical varietals in Kenya, up to 2500 trees per ha. The end result is a yield of up to 5 tons per ha under optimal management, versus an average of 2 tons/ha. Batian also has a large bean size, which must also contribute to yield estimates.

What does this mean for the environment?

On the plus side, if Batian does show good resistance to fungal diseases (one news piece implies Batian has complete resistance), it may reduce the use of copper fungicides. While often considered allowable under many organic standards, their extensive and prolonged use on coffee in Kenya has resulted in soil contamination. Copper fungicides are already applied many times a year on Kenyan coffee. If rain is frequent, it must be reapplied more often because it is washed off (and fungal diseases are worse in wet conditions). If dependence on fungicides can be reduced or eliminated, this would be a huge accomplishment, and very positive for the environment.

There is a growing movement in Kenya, where most coffee is grown in the sun, to plant shade trees and also reforest many areas. I am not sure it is possible to grow many shade trees and also grow Batian at the recommended density, which is essentially a coffee tree every 2 m. But, (as pointed out in the comment section below and amended here) if farmers don’t have to worry about fungal diseases they may be more apt to plant shade trees.  (I will do a post on coffee berry disease and shade similar to the one on coffee leaf rust some time this fall.)

The CRF and government is also encouraging the planting of Batian in areas where it is currently not being grown, particularly in western Kenya.  Bungoma, Kasii, and Nyanza are current western coffee regions and I have not found details on whether these are the areas being targeted, or some other districts. It’s my understanding that west Kenya gets more rain than the central region where most coffee is grown, and that may be why Batian is being pushed there — coffee planted at high densities usually requires more moisture. Unfortunately, densely planted coffee often also requires heavy fertilization and the trees need to be replaced more often.

Combating diseases, declining yield, and climate change while maintaining quality in a sustainable manner is a challenge to coffee growers worldwide. One can hardly fault farmers for wanting to sustain or improve their livelihoods, or governmental agencies for working to stabilize or increase the production of a primary export crop.  Is another potentially sun-grown, high-input varietal the answer, or environmentally sustainable? We will have to wait and see.

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Revised on March 23, 2014

Posted in Coffee news and miscellany,Coffee regions

{ 6 comments… read them below or add one }

Peter G September 1, 2011 at 12:41 am

I see good reason to be hopeful about Batian.

There is no question that the CRF has heard the message that cup quality must be excellent in order for a new variety to succeed. Although I have not yet tasted a Batian coffee with the classic flavor I attribute to SL-28, I believe it is very possible that breeders have managed to preserve that trait. Particularly hopeful is the mention of Rume Sudan in the breeding stock, which (in my opinion) is what gives SL-28 that inimitable blackcurrant flavor. I am hopeful.

Next, and just as important, is the fungal resistance claimed for Batian. The thing standing in the way of organic agriculture in Kenya is Coffee Berry Disease, and the hyper-use of antifungals to prevent it. I think that new, resistant varieties are key to any successful strategy to develop sustainable agriculture in Kenya.

As for shade growing, the main deterrent to shade growing now in Kenya is fear about CBD. If Batian helps reduce that fear, I consider it much more likely that farmers will start to plant shade again, particularly if organic agriculture in Kenya is supported by roasters. I don’t see anything about Batian which discourages shade growing, especially in comparison to SL-28 and Ruiru 11, both of which are rarely shade-grown.

I likewise don’t know of anything that makes Batian especially “high-input”, except that it aims to be highly productive. Both SL-28 and especially Ruiru were selected for their productivity. Would you consider them high-input too? I’m curious as to why you ask the question in your last paragraph: “is a high-input, sun grown varietal the answer…?”, since this description seems to fit pretty much everything being grown in Kenya already.


JACraves September 1, 2011 at 5:54 am

Hi, Peter! I had more difficulty than usual finding information on the development of Batian beyond what I linked to in the post. Usually a search through peer-reviewed research via all the academic databases I can tap in to brings up some published information on how the breeding was accomplished and the results of field trials. Nothing here. Other sources more or less emphasized or repeated information about high yield under “good” management. I took that (mistakenly, perhaps?) as cultivation under recommended density and with sufficient water and fertilizer with that density…as high or higher than existing varietals? I was speculating, and fishing a bit for comments when I wondered “out loud” if shade can be incorporated into the recommended density at meaningful (for biodiversity and climate mitigation) levels. I have a few Kenyan farmers who comment here on occasion. I landed you, and will change some of the language to reflect your (very welcome) optimism.

I should have also mentioned (and will add) that Batian has a large bean size, which must also contribute to yield estimates.

I hope I didn’t sound like I was poo-pooing Batian. I have read too many papers on soil contamination on Kenyan farms, and am alarmed to read about coffee lands being sold to real estate developers. If Batian — or any other new varietal — can be part of reversing those trends, it is to be celebrated.


Peter G September 1, 2011 at 12:53 pm

I don’t know much about Batian either. The development of it has been closely guarded. The reason for that is that development of varieties has become controversial, and the tendency is to hold things close to one’s chest. I have myself been involved in more than one tense argument over varieties in Kenya, and varieties like Castillo in Colombia have been controversial as well.

The tendency in the coffee industry has been extreme suspicion of ‘modern’ varieties. There is a reflexive idea that the product of science must inherently be worse (in terms of cup quality or farming) than the ‘heirloom’ varieties of the early 20th century or earlier. Likewise, there is the idea that the varieties have been developed to be sun-tolerant and agrochemical-dependent since the 1950s.

I don’t know much about that. What I do know is that many ‘heirloom’ varieties can be grown in full sun, and are in Kenya right now. Plus the heirlooms are often very susceptible to disease, as you point out. The first generation of modern hybrids (like Ruiru) were very poor in the cup, due to canephora genes, and extremely highly productive by way of the compact caturra structure. The new-generation hybrids APPEAR to be bred with cup quality in mind, and I have tasted some delicious new hybrids- like the F1 hybrids being developed from Ethiopian varieties along with catimor types in Nicaragua.

Weighing all the arguments, I think the only way we’ll preserve coffee in places like Kenya or Costa Rica, particularly sustainably-farmed coffee, is with the help of disease resistant, delicious-tasting, productive new varieties. Within the coffee industry, many within the coffee industry will reject these new varieties, based on suspicions. For this reason, I try to stay somewhat positive and open about the new varieties.

Peter G


David Masika Wepukhulu May 25, 2012 at 8:01 am

I am from Kenya. The information is quite informative. I am a small scall coffee farm who aspires to engage in large scale coffee farming, sales and marketing. With this information, I appear late in the game, but happy for now. I can access the market as early as I access the website. Keep it up. Regards/David


Bernard Mukasa November 16, 2012 at 6:37 am

I wish to set aside 2 acres of my farm in Webuye Kenya for coffee it a viable investment ? What are the possible risks? Advise on the best variety and source of seedlings.


JACraves November 16, 2012 at 8:59 am

I wish I could help, but I am not an agronomist and have no direct connection to Kenyan coffee farming. Please try contacting the Coffee Board of Kenya for assistance. Good luck!


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