CROP PRODUCTION II (PLANTING)   

CROP PRODUCTION II (PLANTING)     

CROP PRODUCTION II (PLANTING) ,Planting.

Placement of planting material in the soil for the purpose of regeneration.

Types of planting materials.

• Seeds
• Vegetative materials.

Seeds.

 Produced by flowering planting.

Advantages of using seeds as planting materials.

• Seeds are easy to treat against soil borne pests and diseases. Ø They are not bulky and thus are easy to store.
• Are easy to handle during planting making operation faster.
• Easy to use machines like planters and drillers.
• Possible to apply manure and fertiliser together with seeds during planting. Ø Possible to develop new crop varieties due to cross pollination.

Disadvantages of using seeds as planting materials.

• Some seeds have long dormancy and may need special treatment.
• Plants raised have variations from the mother plant due to cross pollination. This may introduce undesirable characteristics.
• Soil borne pests may damage seeds if left for sometimes in the soil before rains.
• Seeds may lose viability if stored for a long time.

Vegetative materials.

Plant parts that have ability to produce roots and develop into new plants.

Advantages of vegetative materials.

• Crop from vegetative material mature faster than those from seeds.
• Crop shows uniformity in qualities like disease resistance, seed size, colour etc.
• It is possible to produce many varieties of compatible crops on the same root stock.
• It is easier and faster especially where seeds shows prolonged dormancy.
• Facilitates propagation of crops that are seedless or those that produce seeds that are not viable or have long dormancy.
• Resulting plant has desirable shape and size for ease of harvesting and spraying.

Disadvantages of vegetative materials.

• Does not results in new crop variety.
• Keeping the materials free of disease is difficult.
• Materials cannot be stored for long.
• Materials are bulky and thus difficult to store and transport.

CROP PRODUCTION II (PLANTING)

PLANTS PARTS USED FOR VEGETATIVE PROPAGATION.

1. Bulbils

Tiny sisal plants produced in the inflorescence towards end of the plant growth cycle. Produced by branches of sisal pole. They develop rudimentary roots and fall off.

One sisal plant produce 3000 bulbils.

They are good planting materials and are better than suckers.

2. Splits

Plantlets divided from the existing mother plant with complete leaves and rooting system. Used to propagate pasture grasses and pyrethrum.

3. Crowns and slips Crowns.

Born on top of the fruit and are broken off and prepared for planting. They are better than suckers because:

• Have higher growth rates.
• Give uniform growth.

Slips.

Born on the base of the pineapple fruit. They grow faster than crowns. (22 months) giving average maturity.

4. Suckers

Small plants that grow from the base of the main stem. Have adventitious roots. Used in propagation of bananas, sisal and pineapples. Should be planted when young. However their disadvantage is that they have uneven growth leading to maturity at different times.

5. Tubers

Underground storage organs which are short and thick.

 Types of tubers.

Root tubers.

Develop from thickening of the adventitious roots. They are not commonly used because they produce weak stems.eg sweet potato.

Stem tubers.

Have auxiliary buds ‘eyes’ that sprout to produce stems.

They are swollen with scale leaves.

Example.  Irish potato.

6. Vines

Soft wood cutting that produce roots easily upon planting. They are taken from rapidly growing shoots and roots are produced from the nodes.

7. Cuttings and setts.

Cuttings are portions of plant parts (stems, roots or leaves) cut and planted. They should have a bud (stem cutting) while the root cutting must have an éye’.They may be induced to produced roots by use of rooting hormones. Cutting of Napier grass and sugarcane are planted directly on the seedbed while tea cuttings are raised in special nurseries first.

Stem cutting used to propagate sugarcane are called setts and have 3-5 nodes and are 3045cm long.

FACTORS AFFECTING ROOTING OF CUTTING.

1. Temperature

Warm temperature are require for the root zone and cool temperatures for the aerial parts.

22-27⁰c day time and 15-21⁰c at night.

2. Relative humidity.

High humidity lowers transpiration and increases leaf turgidity. Cuttings should be kept in a greenhouse or under shady conditions or spraying the area with water to keep it moist.

3. Light intensity.

Softwood cuttings need high intensity of light as it promotes production of roots by hastening photosynthesis. Hard wood cutting requires dark condition as they have high amount of stored CHO.

4. Oxygen supply.

Required for root development. Therefore ensure the rooting medium allows proper aeration.

5. Chemical treatment.

Rooting hormones that promotes production of roots in cuttings.eg IAA (indoleacetic acid)

6. Leaf area.

Soft wood cuttings requires a lot of leaves for photosynthesis while hard wood cutting will produce roots better without leaves.

CROP PRODUCTION II (PLANTING)

SELECTION OF PLANTING MATERIALS.

Factors to consider.

1. Suitability to the ecological conditions.

Should be well adapted to the soil conditions, temperatures and amount of rainfall in the area.

2. Purity of the materials.

Low seed rate are used for pure seeds in comparison to impure seeds.eg seeds mixed with chaff other types of seeds.

3. Germination percentage.

It is a measure of the germination potential of seeds expressed as a %age.

It helps to determine the seed rate of crops. Seeds with a higher germination % will require a lower seed rate.

4. Certified seeds.

These are seeds tested and proven to have 100% germination potential .they are free from pests and diseases and are high yielding.

PREPARATION OF PLANTING MATERIALS.

1. Breaking seed dormancy Dormancy.

Period/stage whereby the seed cannot germinate.

Methods of breaking seed dormancy.

1. Mechanical method.

Amis at making the seed coat permeable to water .scarification is done by rubbing small sized seeds against hard surfaces e.g. sand paper or nickling the seed coat with a knife for largesized seeds e.g. Croton.

2. Heat treatment.

Involves use of hot water or burning the seeds lightly therefore softening the seed coat. Seeds are soaked in hot water 80⁰c for 3-5 min. e.g. in Leucaena calliandra, and acacia.

3. Chemical treatment.

Involves dipping the seeds in chemicals e.g. concentrated sulphuric acid. The chemical will wears off the seed coat.

4. Soaking in water.

Involves soaking the seeds in water for 24-48 hours until it swells.

1. Seed dressing.

It is the coating of seeds with fungicides or an insecticide or a combination of the two to protect seeds from soil borne pests and diseases.

C. Seed inoculation.

Coating of legume seeds with the right strain of Rhizobium bacteria to encourage nodulation and nitrogen fixation.

Inoculated seeds should not be dressed as it kills the bacterium. Plant the seeds in moist soils to avoid dehydration that will kill the bacterium.

D. Chitting/sprouting.

Spouting of seed potatoes before planting to break dormancy. Should be done in a partially dark room. Diffused light encourage production of short green and healthy sprouts.

Complete darkness results in long, pale thin spouts that break easily during planting.

The potatoes should be dusted with dimethoate to control potato aphids and tuber moth. Rendite should also be used to break dormancy.

CROP PRODUCTION II (PLANTING)

TIME OF PLANTING

Factors to consider in timing planting.

• Rainfall pattern/moisture conditions of the soil.
• Type of crop to be planted.
• Soil type.
• Market demand.
• Prevalence of pests and diseases. Ø Weed control.

Advantages of timely planting.

• Crops benefits from nitrogen flush available at the beginning of the rain.
• Crops establish earlier than weeds hence smothering them.
• Crops escape serious pest and disease attack.
• Crops makes maximum use of rainfall and suitable soil temperatures.
• For horticultural crops proper timing ensures that the produce is marketed when prices are high.

Methods of planting.

Broadcasting

Row planting.

 Broadcasting. 

Scattering seeds randomly all over the field in a random manner.

Advantages of broadcasting.

• Easier, quicker and cheaper.
• Give a good ground cover which helps to control soil erosion and smothers weeds.

Disadvantages of broadcasting.

• Seeds are spread unevenly leading to overcrowding in some places.
• Requires a higher seed rate than row planting. Ø Weeding cannot be mechanised.

Row planting.

Planting material are placed in holes or furrows in rows.

Advantages of row planting.

• Machine can be used easily between the rows.
• It is easy to establish the correct plant population.
• Lower seed is used as compared to broadcasting.
• It is easy to carry out cultural practices such as weeding, spraying and harvesting.

Disadvantages of row planting.

• Requires some skills in measuring distance between and within rows.
• Time and labour consuming thus more expensive.
• Does not provide ample foliage cover thus erosion is likely to occur.

Over sowing. 

Introduction of a pasture legume in an existing grass pasture.

The growth of the existing grass is suppressed first through

• Burning Ø Slashing
• Heavy grazing.

Under sowing.

Establishment of a pasture under a cover crop usually maize.

Benefits.

Facilitate intensive land utilisation.

Encourage early establishment of pasture.

 Plant population.

Ideal number of plants that can be comfortably accommodated in a given area without overcrowding or too few to waste space.

Plant population= Area of land\spacing of crop.

Example.

Given that maize is planted at a spacing of 75X 25cm, calculate the plant population in a land measuring 4x3M.

Area of land/spacing   = 400cmX 300cm/75cmX25cm

= 64 plants.

Spacing.

Distance between and within the rows.

Wider spacing leads to a reduced plant population leading to low yields.

Closer spacing lead to overcrowding and competition for resources.

CROP PRODUCTION II (PLANTING)

FACTORS DETERMINING SPACING.

1. Type of machinery to be used.

Space between rows should allow free passage of the machines.

1. Soil fertility.

A fertile soil can support high plant population thus closer spacing.

1. Size of the plant.

Tall crop varieties require wider spacing than shorter varieties.

1. Moisture availability.

High rainfall areas can support a large number of crops thus a closer spacing.

1. Use of the crop.

Crop grown for forage or silage material requires a closer spacing than crop grown for grain production.

1. Pest and disease control.

Properly spaced crops makes it difficult for pest to move from one place to another.

1. Growth habit of the crop.

Spreading and tillering crop varieties require wider spacing than erect types.

SEED RATE.

Amount of seeds to be planted in a given unit area Correct spacing.

Avoids overcrowding of crops which lead to competition for growth resources.

Helps to control diseases and pests.

Factors to consider in choosing seed rates. 

1. Seed purity.

Pure seeds have a high germination % thus lower seed rate as opposed to impure/mixed seeds.

2. Germination%

Seeds of lower germination% requires a high seed rate.

3. Spacing

At closer spacing, more seeds are used than at wider spacing.

4. Purpose of the crop.

Crop to be used for silage and forage is spaced more closely than one meant for grain production thus will require more seeds.

 DEPTH OF PLANTING.

Distance from the soil surface to where the seed is placed.

Factors determining depth of plating.

1. Soil type.

Seeds emerge from greater depth in sandy soil that are light than in clay soils.

2. Soil moisture content.

Deep planting is done in dry soils in order to place the seeds in a zone with moist soil.

3. Size of the seed.

Larger seeds are planted deeper because they have enough food reserve to make them shoot and emerge through the soil.

4. Type of germination.

Seeds with epigeal type of germination e.g. beans should be planted shallowly than those with hypogeal germination.

CROP PRODUCTION II (PLANTING)

ALL AGRICULTURENOTES FORM 1-4 WITH TOPICAL QUESTIONS & ANSWERS

PRIMARY NOTES, SCHEMES OF WORK AND EXAMINATIONS