Catha edulis

Cultivation Details

Khat is cultivated in highland areas of the tropics and subtropics at elevations of 1,500 - 2,500 metres^[1]. In these areas the average daily temperatures are around 16 - 22°c (within a total range of 6 - 32°c). The annual rainfall requirements are 800 - 1,000 mm over a period of 4 - 6 months^[1]. Frost and high humidity are growth-limiting factors^[1]. Khat can be grown in a wide range of moderately acid to alkaline soils, from sandy loams to heavy clays, sufficiently deep and well drained, with a high organic matter content in the topsoil^[1]. It is not salt tolerant^[1]. Khat is predominantly a smallholder crop; farmers intercrop young khat plants with food crops during the first 5 - 6 years, after which shade from the trees becomes too heavy for intercropping. A mixed cropping system of a few rows of khat alternated with one or two rows of coffee (Coffea arabica L.) is not uncommon in Ethiopia^[1]. Khat is left to grow undisturbed for 3 - years, until about 0.8 - 1 metre tall. Most leaves are then removed to induce the development of young shoots for a first light harvest. Normal yield levels are reached at 5 - 8 years after planting. The height of plants is maintained at 2.5 - 5 metres by regular pruning. Trees can be rejuvenated by cutting back all stems close to ground level and allowing emerging suckers to develop into new stems^[1]. In this way plantations can be kept productive for 50 - 75 years without replanting^[1]. Flowering generally occurs during the rainy season, the fruits maturing within 4 months^[1]. Khat is often grown for home or local consumption and only harvested when the need arises. Such khat plots are not very productive. In market-oriented khat producing regions of Yemen and Ethiopia, yields can be as high as 2 tonnes of fresh shoots per hectare per year for well-managed orchards. Average annual yields in Ethiopia are reported to be 800 - 1,000 kg/ha^[1]. The genus Catha consists of one highly polymorphic species within which there are several cultivated forms^[1]. In Ethiopia, farmers distinguish several cultivars, including 'Dallota' with small pale green leaves, 'Dimma' with medium-sized red leaves and 'Mohedella' with green to olive-green leaves. In Yemen, khat cultivars are sometimes named after a location, e.g. 'Sabri', 'Reimi', 'Taizi' and 'Mathani', or their coloration^[1].