Introduction 

• There are many crops cultivated in Kenya. 

• These crops are grown for various uses and require different ecological conditions. 

Definitions: 

• Hybrids - These are crop varieties developed by crossing two pure lines.

• Composites - These are crop varieties developed through repeated mass selection. 

• Cultivars - these are varieties of crops which are cultivated in a given area. 

Maize 

• Main growing areas: Trans-Nzoia, Nakuru, Uasin Gishu, Laikipia districts and others. 

• Ecological Requirements 

- Altitude: Upto 2000m above sea level. 

- Temperature: About 25°C 

- Soils: Freely draining, fertile loam soils. 

- Rainfall: 750-12S0rnm critical at silking and pollination stage. 

• Varieties 

- High altitude areas: Hybrids 611, 613 and 614C. 

- Medium altitude areas: 511,512,622 and 632. 

- Marginal rainfall areas: Katumani composite and Makueni composite. 

- Coast regions: Coast composite and Katumani composite. 

Seedbed Preparation 

• Ploughing should be deep and done during the dry season to eradicate weeds. 

• Require medium tilth. 

• Plant spacing 75-90cm x 20-30cm. 

• Planting done at the onset of the rains. This helps to reduce pest attack. 

• Dry planting in areas with inadequate rainfall is necessary. 

Field Maintenance: 

• Apply phosphatic fertilizer during planting at a rate of 120kg/ha P2O5 

• Also nitrogenous fertilizers as top dress at the rate of 200kg of ASN or CAN. 

• Control weeds by cultivation, use of appropriate herbicides, uprooting, slashing and mulching. 

Pest Control 

• Maize Stalk Borer: 

- Nature of damage: Boring the leaves causing windowing effect, boring the stems and cobs. 

- Control: Destruction of previous years crop residue, closed season and apply chemicals 

• Maize Weevils: 

- it is a storage pest. 

- Damage: Bores holes into the maize grains, eating the contents. 

- Control: Proper hygiene and sanitation in the stores. 

- Use of chemicals such as Actellic Super. 

Disease Control: 

• Rust 

- Cause: Fungus. 

- Symptoms: Red or brown pustules on the. leaves. 

- Control: Plant resistant varieties and crop rotation. 

• Smuts

- Cause: Fungus 

- Symptoms: Black sooty mass of spores on maize heads or cobs(ear). 

- Control: Crop rotation, growing resistant varieties and destruction of affected plant parts. 

• Maize Streak Virus

- Cause: Virus 

- Symptoms: Yellow longitudinal stripes parallel to the midrib. 

- Control: Certified seed, early planting and rogueing. 

Harvesting 

• Harvest the crop 3-9 months after planting depending on variety. 

• Maize stalks are cut and stocked in the field. 

• Cobs removed by hand. 

• For large scale harvesting, combined harvesters are used. 

• Yields about 3,OOOkg and 4500kg/ha. 

Bulrush Millet 

Areas where grown:

• Lower areas of Kirinyaga, 

• Embu, 

• Meru, 

• Parts of Machakos 

• Kerio Valley. 

Ecological Requirements 

• Altitude: Does well in areas below 1200m. 

• Rainfall: 500-600mrn per annum. 

• Soils: Light sandy soils. 

• Varieties: Serere 2A, 3A, 6A, 17, 16/9  

Seed Bed Preparations 

• Ploughing of land during the dry season. 

• Soil should be of fine tilth since the seeds are small. 

Planting: 

• Done at the onset of the rains. 

• Planted by broadcasting and row planting at a spacing of 60cm x 15cm. 

Field Maintenance: 

• Weeding is done until tillering. 

• Top-dressing is done by use of sulphate of ammonia. 

Pest Control 

      Birds 

• Nature of Damage: Eats the seeds at milky stage. 

• Control: Bird scaring devices. 

Disease Control 

      Ergot 

• Cause: Fungus. 

• Symptoms: Heads become sticky. 

• Control: Use of certified seeds, crop rotation and destruction of affected crops. 

Downy Mildew 

• Cause: Fungus. 

• Symptoms: Long, whitish lines on the leaves. 

• Control: Crop rotation and field hygiene. 

Harvesting 

• Done by cutting off the heads. 

• Drying of the heads. 

• Threshing and winnowing of the grains. 

• Stored under well ventilated dry conditions. 

• Yields about 1000kg/ha with good management. 

Finger Millet 

• Areas where grown: Western Kenya and Uganda. 

Ecological Requirements 

• Altitude: 0-2400m above sea level. 

• Rainfall: 900mm, drought resistant in the early stages. 

• Soils: Free draining fertile soils. 

Varieties:

• Serere varieties developed at Serere in Uganda. 

• Ultra lupin 

• 5.18 oats. 

Land Preparations 

• The seedbed should be thoroughly prepared to a fine tilth due to the small size of the seeds. 

• It also helps to control weeds. 

Field Operations 

Planting 

• Finger millet should be planted as early as possible in the season. 

• It is usually broadcasted by hand. 

• If planted in rows, the furrows should be 30-33cm apart and the plants should be thinned to 5cm apart within the rows. 

Fertilizer Application 

• Sulphate of ammonia at the rate of 125kg/ha is recommended for topdressing finger millet. 

Weed Control 

• Clean seedbed preparation 

• Uprooting 

Pest Control:

• Birds are controlled through scaring. 

Disease Control 

Head blast: 

• Cause: Fungus 

• Symptoms: Brown spots with grey centres on the leaves and stems below the inflorescence. 

• Control: Use of resistant varieties. 

     Harvesting 

• Individual heads are cut with knives. 

• Heads are dried, threshed and winnowed. 

• Yields  1650kg/ha with good management. 

Sorghum 

• It is grown in Western, northern, Rift Valley, Eastern and some parts of Central Province. 

    Ecological Requirements 

• Altitude: 0-1500m above sea level. 

• Rainfall: 420-630mm. It is drought resistant. 

• Soils: Fairly fertile and well drained soils. 

  Varieties 

• Dobbs variety. 

• Serena variety. 

  Field Operations 

  Planting 

• Broadcasting the seeds on the firmly prepared seedbed. 

• Intercropped with other crops especially maize and beans. 

• Can be planted in pure stands at a spacing of 60cm x 15cm 

  Fertilizer Application 

• Responds well to farmyard manure (FYM). 

• Inorganic fertilizers are not commonly used in growing sorghum. 

 Pest Control 

• Bird pests: They are the most common sorghum pests. 

• They include 

• quelea, 

• aethiopica (Sudan Dioch), 

• weaver birds, 

• starling bird 

• bishop's bird. 

• They are controlled through;

• killing them using explosives,

• poison spraying in their breeding places 

• use of flame throwers. 

• Sorghum shoot-fly controlled by early planting, closed season and application of insecticides. 

• Stem borer - control by use of insecticides and field hygiene. 

Disease Control 

       Common sorghum diseases include: 

• Leaf blight 

• Anthracnose. 

• Sooty stripe. 

• Loose smut 

• Head smut 

       Smuts are controlled by seed dressing-while the other diseases are controlled by growing resistant varieties. 

Harvesting 

• Sorghum is ready for harvesting 3-4 months after planting. 

• Heads are cut off using a sharp knife after which they are sun-dried, threshed, winnowed and stored. 

• Up to 3000kg/hectare can be obtained with good management. 

Beans 

• Grown in all provinces where maize is grown. 

Ecological Requirements 

• Altitude: 10.00-2100 metres above sea level. 

• Rainfall: Average of 62Smm per annum. 

• Soils: Well drained loamy soils rich in organic matter. 

Varieties 

  Varieties for dry beans: 

• Rose Coco, 

• Mwezi Moja, 

• Canadian Wonder, 

• Wairimu, 

• Haricot, 

• Mwitemania. 

   Variety for canning: Mexican 142. 

   Varieties for French Beans: 

• Primeur, 

• Long Tom, 

• Saza, 

• Master Piece 

• Monel. 

Seedbed Preparation 

• Land should be prepared early. 

• Primary and secondary cultivation done to control perennial weeds. 

Seed Selection and Treatment 

• Select wholesome seeds free from damage and wrinkles. 

• Seeds are dressed against bean fly. 

• Seeds should be inoculated with appropriate bacteria (none dressed seeds) 

Planting 

• Planted at the onset of the rains. 

• Spacing 30-45cm x 15cm. 

• Apply phosphatic fertilizer during planting time. 

• Plant 2-4 seeds per hole. 

Field Maintenance 

• Provide sticks for the climbing varieties. 

• Control of weeds through shallow cultivation. 

• Top-dress with nitrogenous fertilizer for example CAN. 

Pest Control

• Bean-Fly 

- Nature of damage: Feeds on the stems causing swelling at the roots. 

- This results in wilting and death. 

- Control: Dressing of seeds, early planting and spraying with insecticides. 

• Bean Bruchid (Storage Pest) 

- Nature of damage: Make dark circular windows on the grains. 

- Control: Clean stores, fumigation, and seed dressing. 

Diseases Control 

• Bean Anthracnose 

- Cause' Fungus 

- Symptoms: Brown or black lesions on the underside of the leaves, pods and stems. 

- Control: Growing resistant varieties, crop rotation, destruction of crop residues and spraying with fungicides. 

• Bean Rust 

- Cause: Fungus 

- Symptoms: Red brown pustules on the leaves. 

- Control: Planting resistant varieties and spraying copper fungicides. 

Harvesting 

• Done during the dry season for dry beans and when the pods are dry. 

• Threshing and winnowing done. 

• Sorting of rotten, off types and damaged ones. 

• Sold to National Cereals and Produce Board when dry. 

• For French beans, pick the pods when soft and green. 

• Market immediately to avoid shrivelling. 

Rice Production

     Areas where grown;

• Mwea Tabere Irrigation Scheme 

• Ahero Pilot Scheme in Kano plains. 

• Bunyala in Busia. 

• Bura in Tana River. 

Land Preparation 

• Plots of 0.4 hectare are made with bunds constructed around them. 

• Plots are flooded for four days. 

• Rotavators/jembes are used to work the flooded fields on the fifth day. 

• The land is then levelled and allowed to drain. 

Water Control 

• During land preparation, water level should be about 7.5-10cm. 

• During levelling water level should be  5cm

• Water is drained off completely for direct sowing. 

• For transplanted rice, water level should be 5cm at transplanting. 

• Water level should be maintained at 1/3 the height of plant until maturity. 

• Water should be allowed to flow slowly through the fields. 

• Old water should be changed every 2- 3 weeks if the flow of water is not possible. 

• Water introduced should always be warm to ensure pollination. 

Fertilizer Application 

• S.A applied in the nursery. 

• Rate of 25kg SA for every nursery unit of 18.5m x 18.5m. 

• Phosphatic fertilizers broadcasted in the field. 

• Rate of 120kg ha DSP before planting. 

• S.A applied in the field in two splits before and after transplanting at a rate of 250kg/ha 

Flooding in Rice 

Flood water in rice production is important for the following reasons;

• It provides good conditions for growth such as high humidity. 

• Kills soil organisms. 

• Prevents denitrification. 

Weed Control 

• Controlled through flooding. 

• Appropriate herbicides such as propanil and butachlor are also used. 

Harvesting of Industrial Crops 

• cotton, pyrethrum, sugarcane, coffee and tea. 

Harvesting of Cotton 

Stage of harvesting 

• Takes 4 months to mature. 

• Harvest when bolls are dry and fully opened. 

Method and Procedure 

• In Kenya cotton is picked manually. 

• Sort out grade AR (safi) from grade BR 

• (fifi) into separate containers. 

Precautions 

• Harvest during dry conditions to prevent dirtifying the lint. 

• Avoid use of gunny bags to prevent contamination. 

• Avoid picking leaves. 

• Harvest on weekly basis. 

Harvesting of Pyrethrum 

Stage of harvesting 

• Takes 3-4 months to mature. 

• Harvest the flowers with disc florets which have assumed a horizontal position. 

Methods and Procedure 

• Pyrethrum is picked manually. 

• Flowers are picked by twisting the heads so that no stem is attached. 

Precaution 

• Clean harvesting should be done. 

• Avoid picking leaves. 

• Flowers are placed in woven baskets. 

• Overblown flowers are picked and thrown off. 

• Pick the flowers when the dew is dry. 

• Harvested flowers should be taken to the factory the same day. 

• Avoid compaction of flowers in the basket. 

• Harvesting interval, once in two weeks during the wet season and once in a month during the dry season. 

Harvesting Sugarcane 

Stage of harvesting;

• Take 14-20 months for the plant crop to mature and 12-16 months for the ratoon crop. 

• Sampling of cane is done before harvesting to ascertain the correct sugar content. 

Methods and Procedures 

• Cut the cane at the ground level to avoid yield loss. 

• The green tops are removed from the canes. 

• Harvesting matchet is used for cutting the cane. 

Precaution 

• Cane should be harvested immediately at maturity to avoid lowering quality. 

• The green tops should be removed immediately after cutting to avoid reduction of sugar content by enzyme invertase. 

• Burnt cane should be harvested immediately after burning to prevent rapid inversion to monosaccharides. 

• The cane should be processed within 48 hours. 

Harvesting of Coffee 

Stage of harvesting; 

• Takes 2-4 years depending on the pruning system. 

• Harvest only ripe berries. 

Methods and Procedures; 

• Hand picking is done so that ripe berries can be selected. 

• During picking hooked sticks can be used to bend the tall trees. 

Precautions 

• Only the uniformly ripe berries should be picked. 

• Over-ripe and under-ripe berries should be dried and sold as buni. 

• Ripe cherries should be processed on the same day they are picked. 

Harvesting Tea 

Stage of harvesting 

• It takes 2-4 years for tea to mature depending on the method of bringing young tea into bearing. 

Method and Procedures 

• Tea harvesting is known as plucking. 

• Fine plucking - 2 leaves and a bud are removed. 

• Coarse plucking - 3 leaves and a bud are removed. 

• A straight fitto(straight stick) is used to guide the plucker on the plucking table. 

• Tipping is done by cutting off shoots that appear above the fitto. 

Precautions 

• Plucked tea is placed in woven (well ventilated) baskets to prevent fermenting before it reaches the factory. 

• The plucked tea should be kept in a cool place awaiting transport. 

• It should be processed within the same day of harvesting. 

• Harvesting is done on a weekly basis under wet conditions and once after every two weeks under dry conditions.