CROP PRODUCTION VI FIELD PRACTICES II
FIELD PRACTICES II,MAIZE (Zea mays).
Staple food. Also used as livestock feed. It is processed to produce oil and starch.
ECOLOGICAL REQUIREMENTS.
Altitude of 0-2200M above the sea level. Prefers medium temperatures and rainfall. Prefers fertile alluvial or loam soils that are free draining, does not tolerate water logging. pH neutral or alkaline (6.5-7.0)
Varieties.
Few varieties. Hybrids and composites are grown.
- Kenya flat complex.
Variety low yielding but has good sheathing cover.
- Hybrid
Bred by crossing inbred lines or varieties under controlled pollinations.
- Composite
Bred by growing a number of varieties together under uncontrolled pollination.
Hybrids and composites are altitude specific. Include:
- Medium to high altitude. Kitale hybrids such as H614, H622, H626.
- Embu hybrids for medium altitude. Such as H511, H513.
- Katumani composites for lower altitude zones.
- Coast composites such as Pwani hybrids 1 and 4. S Double cob varieties such as DH01 and DH02.
Selection and preparation of planting materials.
Buy fresh seeds for every planting season because of reduced hybrid vigour in the F1.
Land preparation.
Prepared early to allow stubble enough time to rot.
Harrowing is done where seed bed is rough (to medium tilth)
Continuous cropping should be avoided because it takes a lot of fertility from the soil.
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FIELD PRACTICES II
FIELD OPERATIONS.
Planting.
Done early on onset of rains or dry planting in areas with a short rainy season.
Early planting reduces attack by stalk borers.
Depth of planting is 2.5CM-10CM. one or two seeds per hole at a spacing of 75-90CM.
75CMX30CM- 2 seeds per hole OR 75CMX15CM- 1 seed per hole. For high rainfall potential areas.
90CMX30CM 2 seeds per hole. OR 90CMX 15CM 1 seed per hole. For low rainfall potential areas.
Fertilizer application.
100-q50Kgs of DSP, DAP OR NPK 23:23:0 per Ha is applied during planting.
Topdressing with CAN or SA when the plants are 45CM or knee high or split application at 45cm and before tasselling at 200kg/ha.
Organic manure also applied. (Well rotten and mixed with soil in planting furrows/holes.
Weed control.
Keep seedbed weed free to avoid competition for growth resources.
2-3 weeding done manually or using herbicides e.g. Simazines (pre-emergent) 2,4-D (postemergent).
PEST AND DISEASE CONTROL.
PESTS.
- a) Maize stalk borers (Buseola fusca)
Larval stage of a moth. Makes holes in leaves resulting in windowing. (In early stages).
In older plants, some caterpillars bore into stems and cobs.
Control.
- Early planting.
- Burning infested maize crop remains after harvesting.
- Use of appropriate pesticides at funnel of each plant.
- Army worm. (Spodoptera exmpta).
Larvae of a moth. Occurs as an epidemic and move in large numbers. Are greyish-green in colour with black stripes at the back and both sides.
Eat leaves causing defoliation and only midribs are left.
Control.
Dusting with appropriate pesticides.
- Aphids
Suck sap from the green husks of cobs and leaves. Attacked leaves and husks appear black in colour.
Control.
Use appropriate insecticides.
- Birds
Eat grains at silky stage.
Removal of husks by birds allow water to get in and cause rotting.
Control.
Scaring them away.
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FIELD PRACTICES II
STORAGE PESTS.
- a) Maize weevil. (Sitophilus zeamais).
Most serious storage pest. May attack maize while still in the field.
Makes tunnel beneath the seed coat and circular holes of the surface of the grain.
Control.
- Dusting shelled maize with Malathion.
- Proper storage hygiene (removing previous plant debris from the store).
- Use hermetic storage bags.
- Red flour beetle. (Tribolium castaneum).
Small reddish-brown beetle. Feeds on flour and damaged/broken grains.
Control.
Proper storage hygiene.
- (Rattus rattus).
Attacks stoked and fallen maize and is more serious in store.
Control.
- Using rat proof stores, cats, traps and baits. S Clearing bushes around the store.
Diseases.
White leaf blight.
Fungal disease caused by (Helminthosporium turcium). Causes oval, grey and thin lesions on leaves.
Control.
Use of resistant varieties.
Maize streak.
Caused by a virus spread by grasshoppers. Causes yellow longitudinal stripes that run parallel to the midrib.
Control.
- Use of certified seeds.
- Early planting. S
Rusts.
Caused by Puccina sorghi and Puccina polysora. . Forms red/brown pustules on leaves.
Control.
Use resistant varieties.
Smut.
Fungal disease caused by (Ustilago zeas). Destroys grains and tassels causing masses of black powder.
Control.
Crop rotation.
Harvesting.
Takes 3-9 months depending on variety.
Stalks may be cut and stoked in the field to allow cobs to dry properly. Cobs are removed and placed in store.
De-husking directly in the field without stoking is common. Can be done by use of combine harvesters. Dry seeds to 12-13% moisture content.
Yields 3,000-4,500Kgs per Ha.
Storage.
Seeds should be dried properly to reduce chances of rotting and minimise insect damage.
Marketing.
Done by NCPB where farmers sell their maize grains. Private buyers, maize dealers and livestock food companies may buy directly from farmers.
FINGER MILLET. (Eleusine covanaca).
Can be stored for long (10years) without use of insecticides as it has seeds that dry out quickly and insects cannot fit inside them.
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FIELD PRACTICES II
ECOLOGICAL REQUIREMENTS.
Can tolerate drought in early stages of growth but requires adequate moisture after first month.
Rainfall 900mm annually. Requires fertile free draining soils.
Varieties.
The latest variety is the ultra lupin.
Selection and preparation of planting materials.
Harvested grains are sun dried, threshed, winnowed and stored for use as seeds.
Certified seeds are available from Kenya Seed Company.
Land preparation.
Prepared early removing all perennial weeds. The land is harrowed to a fine tilth.
Weed control is very difficult thus thorough seedbed reduces competition.
Field operations.
Planting.
Plant early to increase the yield. Broadcasted by hand or planted in rows 30-33Cm apart and the plants thinned to 5Cm apart.
Commonly grown as pure stand.
Weed control.
Done manually as it is closely spaced and a jembe cannot be used. Thorough seedbed preparation and sowing in rows reduces the labour required for weeding.
Eleusine africana and Eleusine indica. Are difficult to distinguish from the crop in the early stages of growth.
Fertilizer application.
125Kg/ha of SA applied at 15Cm high increase yield from 450 to 900Kg/ha.
Pest and disease control.
Pests.
The major pest in the field are birds. It is rarely destroyed by pests in the store because of their small size.
Diseases.
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FIELD PRACTICES II
Head blast.
Caused by (Piricularia oryzae).
Common under hot and humid conditions. Causes brown spots with grey centres on leaves, stems are affected below the inflorescence.
Control.
Use resistant varieties.
Harvesting.
Hand knives are used for cutting individual heads.
Heads are dried, threshed and winnowed. Yields 1650Kg/Ha.
BULRUSH MILLET. (Pennisetum typhoides).
Ecological requirements.
Drought resistant and thrives in areas of low rainfall 500-600mm per annum.
Requires warm climate which is prevalent in altitude below 1200M above the sea level.
Requires well drained soils and will perform well even when they are not rich in nutrients.
Varieties.
There are some varieties that are high yielding and disease resistant from Uganda. These are serere26/19, 6A, 2A and 3A. Some have bristles.
Land preparation.
Prepare land early to give soil enough time to settle and form a firm seedbed.
Requires a fine seedbed to give a good seed-soil contact.
Field operations.
Planting.
Commonly done by broadcasting followed by shallow cultivation before onset of rains. For row planting, spacing is 60X15CM.
Weeding.
It is resistant to weeds especially after tillering occurs where it is able to suppress weeds, prior to that, the seedbed should be kept weed free.
Fertiliser application.
SA at a rate of 200Kg/Ha is applied when the crop is at 30CM high.
Pest and disease control.
Pests.
Main field pest are Quelea Quelea, weaver birds and bishop’s birds.
Attack grains at milky stage onwards.
Control.
Fixing bird scaring devices in the field.
Diseases
Downy mildew.
Caused by a fungus (Sclerospora graminicola).
Characterised by long, whitish lines on the leaves.
Control.
- Crop rotation.
- Destroying crop remains after harvesting.
Rust.
Fungal disease caused by (Puccina penniseti).
Characterised by pustules that develop on the leaves.
Control.
- Use of resistant varieties.
Ergot.
Fungal disease caused by (Clavicepts microcephala). Not serious in bulrush millet.
Affected heads becomes sticky.
Control.
- Use of certified seeds.
- Crop rotation.
- Destruction of infected crop residue.
Harvesting.
Done by cutting the heads with a knife or sickle when dry. Threshing is done by beating the dry heads on the ground.
Yields 1000Kg/Ha.
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FIELD PRACTICES II
SORGHUM. (Sorghum vulgare).
Fairly tolerant to drought.
Resistant to waterlogging. Yields reasonably well on infertile soils. Can be ratooned.
Utilisation: grains ground into flour or used for brewing. Young crops used as fodder for feeding livestock but should be wilted first.
Ecological requirements.
Features that makes sorghum drought resistant.
- Has well developed rooting system.
- Has ability to roll up its leaves during hot weather.
- Rainfall requirements is 420mm-630mm per annum thus grows well at altitude below 1500M above sea level.
- At higher altitude poor yields are obtained and the crop is attacked by pests such as shoot fly and downy mildew disease.
- Requires fairly fertile and well drained soils.
Varieties.
Characterised by seed colour and taste.
- White in colour. Palatable.
- Brown/red. Bitter.
Improved varieties.
- Bobbs
Suitable for areas around the shores of Lake Victoria. Seeds are brown and it matures in four months.
- Serena
Crossbreed of dobbs and a variety from Swaziland.
Has brown seeds and matures in 3 ½ months.
Varieties with compact panicles and goose neck have some resistance to bird damage.
Selection and preparation of planting materials.
Seeds are prepared by threshing the dry heads, winnowing and seed-dressing.
Field operations.
Planting.
Done by broadcasting seeds on firmly prepared seedbed.
Sown together with maize and beans.
As a pure stand, the spacing is 60X15CM.
Fertiliser application.
Not commonly used. It responds well to farm yard manure most soils.
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FIELD PRACTICES II
PESTS AND DISEASE CONTROL.
Pests.
Birds.
Major pest. The serious pest is the Sudan dioch (Quelea Quelea aethiopica).
Other birds include: weaver bird, strarling and bishop’s bird.
Sorghum however has natural qualities such as bitter tasting coats in coloured grains that keeps birds away. Similarly the goose necked and compact panicle sorghum varieties are resistant to birds attack.
Control.
Using flame throwers, explosives or poison sprays in their breeding colonies.
Sorghum shoot fly. (Antherigona varia).
Adult fly lay eggs on underside of very young plants. The larvae enters the tunnel and moves down to feed on the young stem killing the shoots. Several tillers then appear and may also be attacked.
Control.
- Early planting. S Closed season.
- Use of appropriate insecticides.
Stem borers. (Busseola fusca).
There are three main species of stem borers attacking sorghum.
- Common maize stalk borer. (Busseola fusca).
It is easy to control as it feeds in the tunnels before moving down to feed on developing tissues.
- Chilo zonellus.
Difficult to control as it does not have distinct population peaks.
- Sesamia
Bore holes straight into the centre of the stem.
Control measures.
- Use of appropriate insecticides.
- Proper disposal of crop remains after harvesting.
Diseases.
Attacked by leaf and inflorescence diseases.
- Leaf diseases.
- Leaf blight. (Helminthosporium turcicum).
- (Colletotrichium graminicola). S Sooty stripe. (Ramulispora sorghi).
Control.
Using resistant varieties
- b) Diseases of inflorescence.
- Loose smut. (Sphacelotheca cruenta). S Head smut. (Sphacelotheca reiliana).
Control.
Seed dressing.
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FIELD PRACTICES II
Harvesting and marketing.
Takes three months. Heads are cut using a sharp knife, sun dried, threshed, winnowed and stored.
Yields’ 500-1500kg/Ha. Can be ratooned for one to two seasons. Marketed through NCPB or purchased directly from farmers.
BEANS. (Phaseolus vulgaris).
Grown for the dry seed and for green pods (French beans). Some are determinate, bush type (non- spreading) and others indeterminate (spreading type).
Ecological requirements.
Do best in well drained loam soils rich in organic matter.
Requires well drained soils (does not tolerate waterlogged soils.).
Requires moist soils throughout the growing period. Requires moderate rainfall. Heavy rainfall is destructive at flowering stage. Requires dry weather during harvesting as rain causes rotting and sprouting of beans. French beans are produced under irrigation.
Varieties.
Dry beans varieties.
- Rose coco (GLP2).
- Mwezi moja (GLP1004). S Canadian wonder (GLP24) S
- Mexican 142(canning variety drought tolerant and resistant to rust.)
French beans varieties.
- Amy
- Mater piece.
- Monel
- Samatha
Selection and preparation of planting materials.
Seeds should be dried before they are planted. Seed selection should be done to discard the damaged and wrinkled seeds.
Should be dressed to control soil borne pests and inoculated with the right strain of Rhizobium.
Land preparation.
Done early to kill all perennial weeds. Beans requires a medium tilth.
Field operations.
Planting.
Planted at onset of rains but during long rains should be delayed to avoid rotting of the crop before harvesting.
Planting at spacing of 30-45X15Cm 2-3 seeds per hole.
Dap at a rate of 200kgs/ha along furrows before planting and manure well rotten and mixed well with soil. Seed rate is 50-60kg/ha.
Weeding.
Filed is kept weed free by shallow weeding. Done before flowering to avoid knocking down flowers. Weed when soil is dry to prevent disease spread.
Irrigation.
Beans for green pods are grown under irrigation and require 50mm/week of water.
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FIELD PRACTICES II
PEST AND DISEASE CONTROL.
Pests.
Bean aphid, bean bruchids, and bean fly and American boll worm.
Control.
S Using appropriate insecticides.
Diseases.
Include: halo blight, anthracnose, bean rust and angular leaf spot.
- a) Bacterial (Halo) blight.
Caused by Pseudomonas phaseolicola.
Causes brown water-soaked lesions on pods. The spot is surrounded by a broad yellow band “halo”.
It is seed borne and spread by rain.
Control.
- Planting healthy seeds.
- Crop rotation.
- Spraying with copper oxychloride.
- b) Anthraconose
Fungal disease caused by Colletrichium lindemuthianum.
Causes brown lesions on pods and stems and brown spots on leaves.
Control.
- Use of clean seeds.
- Dressing seeds with captan.
- Destruction of infected crop residues.
- In wet weather, spraying weekly with copper fungicides/ Mancozeb.
- c) Bean rust.
Fungal disease caused by Uromyces appendiculatus.
Causes pustules of red-brown powdery spores on stems and leaves.
Control.
- Eliminate volunteer bean plants.
- Rotate bean with non-host crops.
- Disinfect poles in production of staked beans.
- Ovoid over application of nitrogen and ensure adequate potassium application.
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FIELD PRACTICES II
Harvesting.
Beans for seeds are harvested by harvested uprooting the dry plants. Uprooting is done when weather is cool to minimise amount of pod shattering.
The beans are then spread on mats or sacks to dry before threshing.
They are threshed by beating with sticks and then winnowed.
Sorting is then done to remove damaged seeds.
French beans. Harvesting of pods starts about nine weeks after planting and continues for two months. Picking should be in dry weather and pods sorted according to size.
Pods should be packed immediately after picking to avoid shrivelling and taken to airport (for export) within 12 hours of harvesting.
Yields 4-5tonnes/ha.
RICE. (Oryza sativa).
Cereal crop grown under paddy irrigation.
Land preparation.
The fields are levelled and bunds constructed around them for controlling water.
Rotavators are used in the flooded fields before transplanting or a jembe is used.
Water control.
Level of water in the field is increased from a very low level of 5cm at planting time gradually to a height of 15cm by time when seedlings are fully grown.
Water is allowed to flow slowly through the filed. If flow of water is not possible then old water should be drained and fresh water added every 2-3 weeks.
Fertiliser application.
SA is applied at a rate of 25kg for each nursery unit. 18.5MX18.5M before sowing.
DSP is broadcasted in the field at a rate of 120kg/ha before planting.
Weed control.
Weeds are easily controlled by the flooding. Those not controlled should be uprooted or used of an herbicide such as Butachor.
HARVESTING OF INDUSTRIAL CROPS.
Industrial crops.
Crops that must be processed first before use.
HARVESTING OF COTTON.
Picked manually. Grading starts at picking. The seed cotton is sorted into two grades.
- AR (Safi). First grade free from insect damage and foreign materials and is clean white.
- BR (fifi).
Carry two containers for each grades.
Precautions during harvesting.
- Care should be taken to ensure no foreign materials e.g. small twigs are mixed with seed cotton.
- Avoid picking when it is wet.
- Do not use sisal bags as their fibres may mix with the seed cotton creating problems during ginning.
HARVESTING OF PYRETHRUM.
Crop remain in production for three years.
Method and procedure of harvesting.
Pick only those having horizontal petals (ray flowers) with 2-3 rows of disc florets open.
Picking intervals 14-21 days but depend on the following.
- Weather conditions.
- Clone used.
- Soil conditions.
Pick by twisting stem so that no stem is attached.
Precautions during harvesting.
- Picked flowers should be put into an open woven basket to allow proper ventilation.
- Avoid using tins or polythene bags that causes fermentation of flowers.
- Avoid picking wet flowers as they may heat up and ferment before they are dry.
- Do not compact flowers in the baskets to discourage heating and fermentation that lowers pyrethrin content.
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FIELD PRACTICES II
HARVESTING OF SUGARCANE.
Takes 18-20 months while a ratoon crop takes 16 months (western).
In coast first crop 14months and a ratoon crop 12 months.
Method and procedure of harvesting.
Before harvesting, samples should be taken for quality testing in the factory. Should have uniform distribution of sugar.
Crop should be cut at ground level to prevent loss of yield and ensure proper establishment of the ratoon. The green tops are removed to avoid some growth substances from flowing back thus lowering quality of sugar.
Harvesting is done using a cane harvesting machete.
Precautions in harvesting.
- Some prefer burning the sugar-cane fields before harvesting to help remove most of the leaves and chase away snakes.
- Canes should be delivered to the factory within 24 hours to ensure quality is maintained.
HARVESTING COFFEE.
Takes 3-5 years from planting to flowering. Takes 8-9 months from flowering to when berries are ready for picking.
Method and procedure of harvesting.
Picking is done by hand.
To have good quality cherry, only the red berries should be picked.
They are then spread on sisal bags to sort out any unripe, diseased, over-ripe and dry berries.
Green berries, dry and undersize are dried to form ‘buni’ which are sold separately at the end of the harvest season.
Precautions in harvesting.
Berries should be delivered on time to the factory on the day they are harvested to maintain quality.
HARVESTING OF TEA.
Pegged tea takes 2 years to harvesting while formative tea 4 years to harvesting.
Method and procedure.
Two leaves and a bud are plucked. The lower leaves have lower caffeine content. Plucking sticks helps the pluckers maintain the plucking table. Plucked tea is put into woven baskets that allow free movement of air to prevent tea from fermenting before it is delivered to the factory.
Precautions in harvesting.
- Leaves should not be compressed in the baskets to prevent heating up and turn brown lowering quality.
- Plucked tea should be kept in cool and shaded place during plucking and while awaiting transport to the factory.
- Should be delivered to the factory on the same day it is harvested.
FIELD PRACTICES II
ALL AGRICULTURENOTES FORM 1-4 WITH TOPICAL QUESTIONS & ANSWERS
