Production of pineapples for processing and fresh markets in Kenya
The pineapple Ananas comosus L. Merr. is a tropical fruit which is grown at altitudes from 100 to over 1800m above sea level with rainfall ranges of 600 to over I500/mm annually. Soils with high murram (high iron or manganese concretions) contents favour pineapple growing while those with high clay content are not favourable. The soil for pineapple growing must be well drained. The slope of the terrain must not exceed 5%. Monocropping of . pineapples gives higher yie~ds than intercropping. It is thus best for commercial pineapple production. A double row system of planting makes field management easier than single row planting and gives higher yields. The use of evenly-sized planting materials as practised by large scale growers_i~ important in the production of fruits of even weight and maturing period. This is further facilitated by the use of flower forcing growth regulators in order to ensure uniform flowering and maturity of fruits of the same age and size. Small scale farmers usually plant mixed propagules that mature unevenly. They also do not use flower forcing growth regulators. Irrigation ensures continous production of pineapple fruits all year round. Rainfed pineapples are, however, seasonal and can fail in times of drought. The use of fertilizers especially Nitrogen fertilizers gives higher yields than those of pineapples grown without any fertilization. Mealy bugs and nematodes are the commonest pests of pineapples in Kenya. Their control is important in order to produce better fruit yields of high quality. Small scale farmers who do not use pesticides produce lower fruit yields of low quality. The use of Diazinon has been found to be effective in controlling mealy bugs whereas, DD Nemagen used as a fumigant controls nematodes. Fungal attacks mainly by Phytophthora spp. are common in fields where fumgicides are not used. Control of these fungal diseases reduces losses both at the field level and after fruit harvest. Production practises for large scale growers are mechanised while those for small growers are manual. However, planting and harvesting are manual operations of both large and small growers. Fruits for . canning are however harvested differently from those intended for fresh markets. Post harvest losses for large scale farmers are very low while those for small scale farmers are high due to poor packaging, transportation and marketing conditions. Large scale growers also have moreinarket openings i.e. processed fruits, 'fresh export and local markets while small scale growers only sell to the local fresh markets. The occurrence of multiple crowns is common when environmental conditions are unfavourable e.g. very high rainfall or a prolonged dry spell.' The same factors also increase leaf and fruit spineness. Rosetting was only observed in fruits produced in virgin lands. Fruits produced at lower altitudes have higher brix to acid ratio than those grown at higher altitudes. However, fruits produced at the same altitude may show different brix to acid ratio due to variation of other climatic factors such as light intensity and temperature. Production practises are also important in determining the final fruit quality. Excessive ratoon crops also reduce the brix acid ratio similar to close spacing which has the same effect. Rosetting increase the acid content of a fruit. The water and sugar content of fruits rise ~ith progressive 'ripening and the acid level goes down. The scale of processed pineapple as well as export of fresh fruits is on the increase in Kenya. The sale of fruits at the local fresh market is also in the rise.