Background Kenya has a huge potential for commercial mango growing. Mangoes are drought – tolerant and can withstand occasional flooding whilst good rainfall distribution rather r than total amount is a prerequisite for flowering and fruit set (Nakasone and Paul, 1998). The tree can be grown from 2 m above sea level l to altitudes slightly above 16 00 m. The tree grows better under the air temperature range of 24 – 30 ° C while under irrigation it can withstand up to 48 ° C (Nakasone and Paull, 1998). Soil preferences for the tree are not exact but places with hard layers to limit root penetration and of high water table (2.5 m) should be avoided.
Other sites not suitable for planting are those with calcareous soils and high salinity. The stated preferred conditions required by mango form the largest area of Kenyan landscape, ranging from sub – humid to semi – arid areas with low population densities that are in agro – ecological zones III – V . Mangoes were introduced in East Africa with the mango africano around 15th and 16th Century by the Portuguese sailors. T he species thereafter has been distributed al l over the region giving way to adaptation and formation of local landraces which are highly variable. Some of the mango populations have been identified as drought, pest and disease tolerant that they have the potential to be adopted as the rootstocks by the horticultural industry (Sennhenn et al . 2011). Sennhenn et al. (2011) noted that the diversity in quantitative a nd qualitative traits is so large that narrowing down to a specific variety is still a daunting task. Some attempts had been made and 95 characteristics were pin – pointed by IPGRI to identify morphological descriptors but it is still a big challenge to use those to settle on specific varieties (Sennhennet al . 2011).
Moreover, most of such characterization has only sampled trees in some areas where mangoes are widely grown in the country. Some of the morphological characteristics are also subject to change w ith the environment. In a study by Kehlenbeck et al (2011) only 50 clearly identifiable mango varieties were found mostly in mother blocks (conservation farms) of research institutes, prisons and lead farmers in Central and Eastern Provinces of Kenya. Most of these varieties consist of the locally selected and introduced commercial mangoes. The most widely cultivated were local varieties Apple and Ngowe while the introduced ones are Kent, Sensation and Tommy Atkins (Kehlenbeck et al , 2011). The other important varieties found during this survey were Haden and Van Dyke. In Coastal area where old trees of mango exist there are a large number of mango varieties k nown in local languages for which detailed scientific descriptions do not exist yet. Commercial mango growing in Coastal area is dominated by varieties such as Ngowe, Apple, Boribo and Kitovu . While the first three are popular for marketing as fresh produce or processed fruit juices, Kitovu is popular as a snack eaten unripe with chilly and salt due to its special aroma and taste. On ripening, the variety still has a long shelf life and it is usually transported for long distances to up – country open markets, where it is popular and affordable. Given the wide ecological range where mangoes grow and intra – specific varieties that exist, most stakeholders find themselves in a position where the y require a guiding tool 3 that can indicate which variety to grow and processes for given products.
The purpose of this task was to initiate the building of a database t hat will guide stakeholders when dealing with a mango enterprise. Survey objective The objective is to establish information, communication and knowledge sharing pathways along the mango value chain t o enhance production and quality of mango, initially focusing on Mbeere, Makueni and Kilifi Districts. Materials and Methods Information to initiate the building of the mango database was collected through literature review, field visits and interviews of with lead farmers and key stakeholders in the three districts. Mango varieties were initially identified through literature and the actual presence and morphological characteristics confirmed through field visits to institutions and farmers that hold them within their premises. The institutions visited included KARI Thika, Embu, Maranj au Prison, Embu, Mwea, Kamurugu Development Initiative and Sunny Factory .
The farmers visited were those that could be identifiable by other farmers in Embu, ishiara , Mundatia, Wote, Kibwezi, Msongareli, Mtito Andei, Teso Chumani, Esamoyo, Soyosoyo, Zowerani, Sunguni and Kadaina Island. Mango Varieties in Kenya Apple Batawi 5 Kent Tommy Atkins Peach Club mango Sensation Kitovu (Dark Green) with Boribo Cultural practices There are two clear practices for mangoes grown in the three regions. The local non – commercial mango varieties are usu ally grown from seeds and maintained that way without pruning or grafting. These type s of mango trees are left to grow wild and much often form tall trees with huge branches and diameter. The commercial varieties are often pruned and grafted thus they are usually retained within reasonable heights for spraying and fruit harvesting. However, in Kilifi and Coast province in general , both local and commercial varieties of mangoes are rarely pruned or grafted that they grown to huge tall trees. Spraying for pests, diseases and yield enhancement is hardly practiced and can be quite challenging.
Harvesting is usually done by people climbing and reaching the fruits 9 Powdery mildew on stem and leaves Leaves of Apple mango infested by Gall flies Haden fruit affected by gall flies and anthracnose Mbeere Survey in mango farms was done in K amurugu area (00° 44 S; 37° 39’E) at elevation of 1120 m, Gitaru Dam (00 ° 46’ S ; 37 ° 43’ E ) at elevation of 956 m and Karurumo – Ishiara (00 ° 28 ’ S; 37 ° 41’E ) at elevation of 1223 m . M ango farming in the area is typically commercial w ith farms ranging from one to 35 hectares . The widely grown varieties are Apple, Kent, Ngowe, Tommy Atkins, Van Dyke and Haden. In Karurumo some farmers have grown a few trees of Keitt and Gesine . The most common challenges facing farmers were limited varieties, diseases and pests. The most widespread diseases were powdery mildew and black spot. Apple mangoes also require spraying against rust. The pests of most economic importance were fruit fly, mango weevil and mango gall flies . The galls swell, deform and perforate the leaves before they fall – off thus reducing photosynthetic potential of the plant. The diseases and pests increase farmers’ in – put costs as they require frequent spray which at times complicates their marketing potential due to chemical residue level settings for external market. There are two channels for mango marketing, namely local and export market. The local market attracts local vendors who transport fruits to accessible urban centers. This market has not set high sanitary standards and most farmers can access it. However, this market is highly affected by glut.
Most mango varieties ripen within a short span of time. Long distance movement of mango away from the local market is also costly in terms of 10 transport and loses due to fruit spoilage on transit. The fruits for external market are inspected for certain qualities which require more intensive management. One of the major challenges noted in dry parts of Mbeere (Kamurugu) is the loss of trees through severe droughts. Some trees in the production age (8 – 10 years) were noted to dry up following long dry spell. Mango gall fly infestation swell, perforate and fall off.
Makueni County In Makueni survey was conducted in Kilome area (01 58 S; 37 20 ’ E) at 1387 m, Makuyuni (01 45 S; 37 27’ E) at 1388 m , Kawala (01 56 S; 37 34’E) at 1212 m and Masongareli (02 19S; 38 08’E) at 780 m. The widely grown varieties of mango are Apple and Ngowe. In Kilome , in addition to those two varieties, farmers have Haden, Kent, Sabine, Tommy Atkins , Van Dyke and Zill. However, there is higher market demand for apple followed by Ngowe. The two varieties are mainly purchased by large scale brokers that prepar e them for export. Commercial farming of man go in Makueni also involve the use of fungicide s and pesticide against powdery mildew, anthracnose, fruit fly mango weevil, mealy bugs, mango gall fly, respectively . In Masongare li, in areas close to the Athi River, mangoes are grown with additional irrigation to encourage early fruiting. H ere trees are weeded and manure added in January and February, then irrigation is done. The trees are then left to flower. Further irrigation is done in June for the apple mangoes to be ready in July. The unripe apple mangoes are in demand in certain markets in Middle – East where they are sold from August to November. The ripe ones are sold in local market in December. This practice usually give the farmers with irrigation systems ahead start and this help s them to dispose of all the produce at a reasonable price per fruit. Weeding and preparation of basins for manure and irrigation in Makueni 11 KilifiIn Kilifi County Mango forms part of the landscape and they have been in existence for many decades.
The economy of the county is based on mangoes, cashew nut and cocoa nut. Most farmers here grow the three trees as a basis for subsistence of which the highest income return comes from cocoa nut, cashew nut and mangoes due to their flowering and fruiting pattern. Cocoa nuts flowers every three months whilst cashew and mangoes flower twice in a year. Flowering of both mangoes and cashew nuts are sometimes severely affected by diseases but only a few farmers invest on IPM. Also, during the harvesting season mango fruit s are affected by pests and blemishes when falling and on transportation such that only 50% of the produce reaches the market in good condition. Only a few farmers grow mangoes on commercial scale of 50 to over 2000 trees. Even within those farms trees are hardly weeded, pruned and sprayed with fungicides and pesticides. Most mango trees planted in Kilifi are from seedlings rather than grafted, which gives intra – varietals and intra – specific diversity. The varieties of mangoes grown in Kilifi are many. They include Ngowe, Apple, Boribo, Kitovu, Batawi, Kent, Mpunda, Dodo, Dodo maji, Kimuzi (Chimuzi), Khovu, Saf ula, Mcharabu, Mteri and many unnamed local varieties. Of these varieties Ngowe and apple are the most marketable. Ngowe ripens early thus it captur es the early market while Apple is known for its sweetness. Kitovu is another variety with a wider acceptability since it is the one eaten unripe with salt and pepper giving it good aroma and taste.
The cost of farming Ngowe, Apple and Batawi are the highest since the first is highly susceptible to powdery mildew, Batawi and Apple are highly susceptible to mango weevil and fruit fly, in addition to rust that affects Apple depending on weather conditions. Batawi has a good taste but it is hardly harvested in good condition due to high susceptibility to maggots of the fruit fly. Kilifi and Coast in general will be the most suitable centre of diversity for mango selection and improvement given the wide diversity observed on farms. Typical mango production system in Kilifi Unknown variety of mango with extra large fruits MANGO IMPROVEMENT Growing of mangoes for commercial purposes is widely taking roots in Kenya. However, the varieties which are being grown widely are limited to Ngowe, Apple, Kent, Tommy Atkins, Van Dyke, Haden and Sensation. Vegetative materials from the same trees are 12 always being transferred and grafted from one place to another, putting the farmers at the risk of relying on a narrow genetic base, transfer o f diseases, pests and low certainty on performance of varieties. In total there are over 70 potential commercial mango varieties in Kenya, but most of them have remained within the mother plantations (conservation stands in research institutes and prisons. There are possibilities of expanding the genetic diversity through raising of seedlings from the existing varieties, selection of intra – specific varieties and spontaneous hybrids in areas such as coastal region where mangoes have existed for more than a century. There is also need for direct involvement in controlled crossing of trees with known traits for improvement. Seedling raising: It is assumed that each seedling is likely to be a separate entity from the mother plant and other sibs, composed of certain trait s which are unique. Some of such traits could be useful for commercial development.
This is likely to happen in areas such as Coast where most commercially planted mangoes have been raised from seedlings unlike in other areas where grafts are used Spontaneous hybrids : These hybrids are likely to occur in farms where various varieties have been planted adjacent to each other for many decades. Unless mangoes are deliberately raised from seedling, such occurrences might not be captured and developed for commercial purposes. Controlled crossing: This offers the long term improvement strategy such that trees with known qualitative traits can be combined to produce new varieties with superior characteristics. In all areas that commercial varieties of mangoes are grown in Kenya, it is not easy to relate varieties with ecological conditions. The planting of mango varieties are mostly driven by economic, social and pest/disease tolerance. Only local varieties that have been grown for many years can be related to certain ecological conditions and that makes them the most suitable materials as rootstock for grafting improved mangoes.