J.K Kimemia., Gichimu B.M., and Kathurima C.W.
FROM PRINT ISSUE
Coffee Research Foundation in Kenya has recently released a new coffee variety called Batian. The variety is tall statured, deep rooted, true breeding, resistant to Coffee Berry Disease and Coffee Leaf Rust, and has very good bean and cup quality. In this statement, a brief account is given on the development, early agronomic performance, quality attributes and other unique features of Batian.
After the 1967/68 serious attack on coffee by the Coffee Berry Disease (CBD) and Leaf Rust, breeding work started in 1971 to develop cultivars that combined resistance to the two diseases with improved yields and quality. The programme was initiated under a bilateral technical assistance and agreements between the Netherlands and Kenya. In 1985, the first disease resistant cultivar, Ruiru 11, was released. After the release of Ruiru 11, the breeding programme was advanced to address emerging issues, key among them, challenges in the production of adequate planting materials. Farmers also wanted a variety with features similar to SL28 but resistant to CBD and Leaf Rust. This drive guided the breeders in selection and development of tall statured and true-breeding disease resistant variety, Batian. The variety is high yielding and of good bean and cup quality. The development, early agronomic performance, quality attributes and unique features of Batian are discussed.
Selection Method and Parentage
The cultivar was selected at Coffee Research Station in Ruiru as single tree selections from fifth filial generations of first and second back-cross progenies involving SL4, N39, N30, Hibrido de Timor, Rume Sudan and K7 as the donor varieties and cultivars SL28 and SL34 as the recurrent parents. The cultivar was selected from backcross families by a combination of within family selection and independent culling methods. In this method, the best individuals within the best families were selected solely on the basis of their phenotypic values (within family selection method). The strategy involved simultaneous selection for the important traits, but independently rejecting all the individuals that failed to meet the required standard for any one of the traits under improvement (independent culling level). Performance of cultivar Ruiru 11 was used as a yardstick for discriminating against inferior lines when selecting for resistance to CBD and Leaf Rust, yield and quality. Variety SL28 was also used as a standard when selecting for yield and quality.
Morphological features of Batian
Like SL28, Batian is tall statured (Plate 1), deep rooted with conical to cylindrical plant shape. Morphological characterization grouped Batian in the same cluster with SL28. The branching habit is erect at early stages but later becomes horizontal and tending to become semi-drooping or drooping after successive crop bearing seasons. Batian has long internodes on both the main stem and branches that compares closely to SL28. It produces many primary branches with average to profuse secondary branching, and remains green throughout the year under good management. The young leaves have medium anthocyanin colouration giving a bronze colour but occasionally absent or weak, giving a green-bronze colouration. Mature leaves have medium width which compares closely with SL28. Ripe cherries are larger than those of SL28, elliptical in shape and deep red in colour. Mature beans are large and bold; endosperm is green while the centre cut is mostly singled and straight.
Batian is resistant to CBD and Leaf Rust but other diseases should be controlled as recommended for other varieties. The cultivar has a potential of producing up to 5 tons of clean coffee per ha (in a spacing of 2m x 2m) under good management judging from the third year yield obtained during the National Performance Trials where Batian produced 3.56 tons of clean coffee per hectare. Owing to its deep and extensive root system and resistance to CBD and Leaf Rust, Batian is suitable for all coffee growing zones.
Batian produces very large berries compared to Ruiru 11 and SL28 which produce average sized berries. Under similar management the cup quality of Batian compares to that of the existing commercial coffee varieties in Kenya (Table 1). Like SL28 Batian can be considered as specialty coffee. When well managed the flavor of Batian has this unique Kenyan character mainly sought by coffee traders. The Kenyan traders described it as sweet with good acidity, complex flavor and full body. Batian also contains relatively lower caffeine than Ruiru 11 and SL28.
Table 1: Differences in seven sensory attributes present in Batian, Ruiru 11 and SL28 as evaluated by Coffee Quality Institute (CQI) and Kenyan cuppers
Merits of the Batian at a glance
- It’s true breeding and therefore seed production is made easier.
- Comes into production in the second year while traditional varieties do so in the third year, hence early flow of benefits.
- Cherry ripening comes earlier than SL28 and Ruiru 11.
- Its production is highly economical as no chemical control against CBD and Leaf Rust is required.
- It’s high yielding with good bean and cup quality.
- It’s suited for all coffee agro-ecological zones.
The planting materials are available at Coffee Research Foundation. To convert the susceptible traditional varieties to Batian, top working on mature plants in the field is recommended. This can be done when the suckers are at pencil thickness stage.
Variety testing and evaluation was financed by Common Funds for Commodities (CFC) through Coffee Leaf Rust Project, European Union through Quality Coffee Production and Commercialization support Programme (QCPCP) and Coffee Research Foundation (CRF), Kenya. Thanks are due to CRF scientific sections which participated in this dauting task especially Breeding, Pathology and Chemistry Sections. Assistance from both technical and field staff of the named scientific sections of CRF is highly appreciated.