CROP PRODUCTIVITY VI ( FIELD PRACTICES II )

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:
  • 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,

   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.
(Visited 196 times, 1 visits today)
Share this:

Written by