Lesson Note on Agricultural Science SS 2 Second Term

Agric Science Lesson Notes for SS 2 First Term – Edudelight Lesson note

WEEK                       SCHEME OF WORK AGRIC SCIENCE SS 2

1-2                               Pasture and Forage Crops

3                                  Forest Management

4                                  Floriculture

5-6                               Diseases of Crops

7-8                               Pests of Crops

9                                  General Prevention and Control of Crop Pests

10                                Revision

11-12                           Examination

TEXT BOOKS

  1. Essential Agricultural Science for Senior Secondary Schools by O. A Iwana
  2. Prescribed Agricultural Science for Senior Secondary School.
  3. WAEC Past Questions and Answers Booklet

WEEK ONE AND TWO                                                     Date: __________

TOPIC: PASTURE AND FORAGE CROPS – LESSON NOTE

CONTENT

  • Meaning, uses and types
  • Factors affecting the distribution
  • Management, practices of pastures

MEANING OF PASTURES AND FORAGE CROPS

Pasture: This is a piece of land on which forage crops grow.

Forage Crops: These are plants cultivated (or growing naturally) whose vegetative parts (leaves and stem) are fed on by livestock.

USES OF FORAGE CROPS

  1. They are used as livestock feeds
  2. They are used as cover crops which conserve soil moisture.
  3. They help in discouraging weed growth
  4. Some are leguminous in nature which enrich soil nutrient.
  5. For prevention of erosion
  6. Used as green manure
  7. Used for roofing farm steads
  8. As bedding materials

TYPES OF PASTURES

  1. Natural pasture: also called natural grassland or rangeland is piece of land on which grasses and legumes grow naturally on their own and are fed upon by farm animals

CHARACTERISTICS OR FEATURES OF NATURAL PASTURE

  1. It contains poor quality grasses and legumes.
  2. It contains soil types that are low in fertility or nutrients.
  3. It contains wide varieties of grasses and legumes, some of which may not be eaten by livestock.
  4. It has good regenerative ability.
  5. Crops here can withstand trampling.

EVALUATION

  1. What are pastures and forage crops?
  2. List five uses of forage crops.
  • Artificial pastures: this is also referred to as established or sown pasture is a piece of land that is where grasses and legumes are cultivated and managed by man to be fed by livestock.

CHARACTERISTICS FEATURES OF ARTIFICIAL PASTURES

  1. It contains high quality grass and legumes
  2. It contains no weed.
  3. Selected grasses and legumes are grown in adequate proportion
  4. Have high regenerative ability
  5. Can withstand trampling by farm animals.

QUALITY OF A GOOD PASTURE PLANT

  1. Ability to regenerate fast after being browsed
  2. Ability to withstand trampling
  3. It must be highly palatable
  4. It must possess high value of nutrients
  5. Ability  to withstand extreme climatic condition
  6. It should have moderate moisture content or succulent
  7. It must have high leaf to stem ratio

EVALUATION

  1. List five characteristics of a natural pasture.
  2. List five characteristics of artificial pasture.

COMMON GRASSES AND LEGUMES OF LIVE STOCK

GRASSES

COMMON NAME               BOTANICAL NAME

  1. Elephant grass             Pennisetum purpureum
  2. Guinea grass                Panicum maximum
  3. Giant star grass           Cynodon plectostachyum
  4. Carpet grass                Axonopus compressus
  5. Spear grass                  Imperata cylindrical
  6. Bahama grass              Cynodon dactylon
  7. Northern gamba          Andropogon gayanus
  8. Southern gamba          Andropogon tectorum

LEGUMES

COMMON NAME               BOTANICAL NAME

  1. Centro                         Centrosema pubescens
  2. Stylo                            Stylosanthes gracilis
  3. Kudzu or puero           Pueraria phaseoloides
  4. Calapo                         Calapogonium mucunoides
  5. Mucuna                       Muccuna utilis
  6. Sun hemp                    Crotalaria juncea

FACTORS AFFECTING THE DISTRIBUTION OF PASTURE

  1. Climatic factors
  2. Soil or edaphic factors
  3. Biotic factors
CLIMATIC FACTORS

The type of climate in an area influences the type of vegetation in the particular area e.g sudan type of climate will favour the growth of grass and legume while equatorial climate does not. The elements of climate which affects the distribution of pastures are rainfall, wind, temperature, relative humidity etc.

EDAPHIC FACTORS

This refers to the level of fertility of the soil. Fertile soil enhances pasture growth and vice versa. Edaphic factors include soil PH, soil texture, soil structure, soil topography etc.

BIOTIC FACTORS

Biotic factors like diseases, pests, parasites, predators generally influence the distribution of pasture. Also human and animal activities such as bush burning and overgrazing will affect the distribution of pastures.

EVALUATION

  1. List four grasses and their botanical name
  2. List four legumes with their botanical name

FACTOR AFFECTING THE PRODUCTIVITY OF PASTURES

  1. Persistence: ability to survive and spread by vegetative means.
  2. Aggressiveness: ability to compete favourably with other weeds.
  3. Resistance to trampling.
  4. Seed viability or profuseness or ease of propagation.
  5. Resistance to drought.
  6. Absence of pest and diseases.
  7. Good management.
  8. Adequate stocking.

ESTABLISHMENT OF PASTURES

Before pasture can be established, the following factors should be considered

  1. Adaptation of species
  2. Palatability
  3. compatibility
  4. time of maturity: should be short
  5. lifestyle of the species

STEPS IN ESTABLISHING A PASTURE

  1. Site selection.
  2. Clearing of land.
  3. Removal of debris
  4. Cultivation of site (land preparation).
  5. Planting of pasture crop.
  6. Supplying.
  7. Promotion of tillers (more point of growth).
  8. Weeding.
  9. Fertilizer application.
  10. Irrigation.
  11. Paddocking.

CLASS ACTIVITY

Example 1 page 184 of Essential Agricultural Science by O. A Iwena.

MANAGEMENT PRACTICES IN PASTURE

  1. Burning (when forage becomes fibrous to ensure regrowth of lush forage).
  2. Fencing to discourage overgrazing or facilitate rotational grazing.
  3. Fertilizer application or manuring.
  4. Regular weed control.
  5. Adequate pest and disease control.
  6. Irrigation.
  7. Adequate stocking.

GENERAL EVALUATION

  1. List three pasture grass and their botanical names.
  2. List three pasture legumes and their botanical names.
  3. List three factors affecting the distribution of pastures.
  4. List five factors affecting the productivity of pastures.
  5. List five management practices in pasture.

PROJECT

Produce a forage album containing no less than twelve mixtures of grasses and legumes to be submitted before sixth week.

READING ASSIGNMENT

Revision questions 4, 6 and 7 in Essential Agricultural Science for Senior Senior School, chapter 17, page 185.

WEEKEND ASSIGNMENT

SECTION A

  1. Which of the following is not a climatic factor affecting pasture distribution? A. Temperature B. Light C. Humidity D. Soil PH
  2. The following are edaphic factors except A. soil PH B. soil texture C. soil structure

D. relative humidity

  • Diseases, pests, predators and parasites are ____ factors. A. biotic B. abiotic C. edaphic

D. climatic

  • The act of re-planting pastures that fail to germinate is ______. A. thinning B. supplying C. weeding D. mulching
  • The following are legumes except _____. A. centro B. stylo C. calapo D. gamba

SECTION B

  1. A. What is pasture?

B. Briefly discuss three factors affecting the productivity of pasture.

  • A. Explain what is meant by natural grassland.

            B. List five grasses and legumes each with their botanical names.

WEEK: THREE              Date: __________

TOPIC: FOREST MANAGEMENT – LESSON NOTE

CONTENT

  • Meaning of forest
  • Forest reserve in Nigeria
  • Importance or uses of the forest
  • Management of the forest

FOREST

Forest can be defined as a large area of land covered with trees and bushes, either growing wild or planted for some purposes which serves as habitat to various kinds of animals.

Forestry is the management of forest and forest resources.

Silviculture is the growing and cultivation trees.

Forest ecology is the scientific study of interrelated organisms in the forest.

COMMON FOREST TREES

Common forest trees found in the forest are Iroko, Obeche, Mahogany, Nigerian walnut, Ebony, Camwood, Opepe, Afara, Teak and Abura.

FOREST RESERVES IN NIGERIA

Forest reserves are large areas of land where plants, either growing naturally or planted are specially preserved for specific purposes.

SOME FOREST RESERVES IN NIGERIA

  1. Mamu River Forest Reserve in Anambra State.
  2. Omo Forest Reserve in Ogun State.
  3. Afi River Forest Reserve in Cross Rivers State.
  4. Okomu Forest Reserve in Edo State.
  5. Shasha River Forest Reserve in Ogun State.
  6. Zamfara Forest Reserve in Zamfara state.
  7. Sanga River Forest Reserve in Plateau state.

EVALUATION

  1. What is Forest?
  2. List five common forest trees

IMPORTANCE OF FOREST AND ITS RESOURCES

The following are ways in which the forest and its resources are important to us. They are as follows:

  1. Provision of food.
  2. Provision of fuel.
  3. Provision of medicinal herbs.
  4. Provision of employment (lumbering).
  5. Forest serves as wind break.
  6. Formation of rain.
  7. Prevention of soil erosion.
  8. Addition of nutrients to soil.
  9. Home of wild animals.
  10. Forest serves as tourist centre.
  11. Provision of foreign exchange.
  12. It beautifies the environment and serves as tourist sites.
  13. Reduction of atmosphere pollution.
  14. Sources of raw materials such as pulp, timber, dye, gum latex etc.

MANAGEMENT OF THE FOREST

The following are management practices that will ensure a constant supply of timber in the forest:

  1. FOREST REGULATION:

These are laws promulgated by government in the form of edicts, decrees and bye laws to prevent people from exploiting or indiscriminate tapping of forest resources.

  1. The prohibition of bush burning
  2. Ban on indiscriminate cutting of timber trees
  3. Encouraging people to plant trees
  4. Ban or collection of leaves and firewood from the forest
  5. Ban or farming in forest reserves
  6. Ban or cutting down of under aged trees
  7. People are to obtain licences so as to secure the permission to enable them cut down trees for human needs.
  • SELECTIVE EXPLORATION

This is the process of cutting or harvesting only mature trees in the forest

ADVANTAGES OF SELECTIVE EXPLORATION

  1. It ensures the concentration of selected species of timber in the forest
  2. It protects soil from erosion
  3. It ensures continuous supply of timber
  4. It serves as revenue base for the government
  5. It prevents indiscriminate felling of timber
  6. DEFORESTSATION

This is the continuous or indiscriminate removal of trees without replacing them.

CAUSES OF DEFORESTATION

  1. Unfavourable climatic factors such as draught, wind blast etc
  2. Man’s farming activities such as bush burning, shifting cultivation etc.
  3. Timber exploitation
  4. Mining/industrialization
  5. Natural disasters
  6. Bad government policies

EFFECTS OF DEFORESTSATION

  1. It encourages soil erosion.
  2. It leads to reduction in fertility of soil.
  3. It reduces the amount of rainfall in an area
  4. It reduces soil moisture content
  5. It increases leaching of plant nutrient
  6. It destroys the microclimate and warms up the environment
  7. It may lead to desert encroachment

EVALUATION

  1. List five importance of forest
  2. Explain selective exploration
  • REGENERATION

Regeneration is the process of forest re-growth after it has been exploited. It is a deliberate effort to grow trees.

TYPES OF REGENERATION

  1. Natural Regeneration: in this type there is re growth of new plants from the old stump
  2. Artificial regeneration: this involves the planting of new forest seedlings in a deforested area.

ADVANTAGES OF NATURAL REGENERATION

  1. It is less expensive when compared with the artificial regeneration
  2. It does not require formal stages in plantation establishment
  3. It brings about the stabilization of natural ecosystem
  4. It does not require special management skill
  • AFORESTATION

This is the process of establishing forest plantations in any area.

ADVANTAGES OF AFORESTATION

  1. It leads to addition of organic matter
  2. It provides regular supply of raw materials e.g timber for industries
  3. It prevents desert encroachment
  4. It increases forest fauna (wild life) in the area concerned
  5. It prevents leaching of plants nutrient
  6. It increases soil moisture retention
  7. It increases the amount of rain fall
  8. It improves the soil structure
  • TAUNGYA SYSTEM

Taungya system is defined as the planting of arable crops at early stage of forest establishment and the arable crops are harvested before the trees form canopies.

CONDITION NECESSARY FOR THE PRACTICE OF TAUNGYA SYSTEM

The conditions which may favour the practice of taungya system include:

  1. Scarcity of land
  2. Over population
  3. Unemployment
  4. Government policies
  5. Low standard of living

ADVANTAGES OF TAUNGYA FARMING

  1. Varieties of crops are harvested
  2. There is availability of crop produce throughout the year
  3. When leguminous crops are used they fixed nitrogen to the soil
  4. Solves the problem of land scarcity
  5. It increases the income of the farmer

DISADVANTAGES OF TAUNGYA FARMING

  1. Reluctance in releasing fertile soil
  2. Cultivation of selected crops
  3. Competition between crops and trees
  4. Inability of some crops to survive

GENERAL EVALUATION

  1. Define Taungya farming
  2. List three advantages of Taungya farming
  3. What is regeneration?
  4. List the types of regeneration
  5. List the causes of deforestation

RESEARCH

Find out the botanical names of ten common forest trees.

READING ASSIGNMENT

Revision questions 6 and 7 in Essential Agricultural Science for Senior Secondary Schools chapter 23, page 228

WEEKEND ASSIGNMENT

SECTION A

  1. The indiscriminate removal of trees is called____. A. aforestation B. deforestation C. taungya farming D. weeding
  2. The following are forest trees except ____. A. iroko B. obeche C. hibiscus D. ebony
  3. Process of establishing a forest plantation is called ____. A. afforestation B. deforestation C. taungya D. weeding
  4. The process of cutting only matured trees in a forest is called ______. A. selective exploitation B. selective exploration C. taungya D. aforestation
  5. The best soil for Agriculture is _____. A. loamy soil B. sandy soil C. clay soil D. silt soil

SECTION B

  1. A. Define forest

B. List ten uses of forest

  1. A. Define deforestation

B. State five effect of deforestation

WEEK: FOUR                                                                                                          Date: __________

TOPIC: FLORICULTURE

CONTENT

  • Meaning of floriculture
  • Importance of ornamental plants
  • Common species of ornamental plants

FLORICULTURE

Floriculture: is a discipline of horticulture that is concerned with the production and management of ornamental plants.

Ornamental plants are beautiful trees or shrubs which can be used to decorate our environments.

IMPORTANCE OF ORNAMENTAL PLANTS

  1. Sources of employment e.g florists.
  2. Serves as source of income.
  3. For expression of love and as gift on special occasions.
  4. For decoration.
  5. For fencing.
  6. For medicinal preparation.
  7. Sources of food.
  8. Purification of the air.
  9. For teaching and learning purposes.
  10. Provision of shades.
  11. Serves as wind breaks.
  12. Beautification of the environment.
  13. Sources of livestock feed.
  14. Serves as tourist centres.
  15. Source of revenue to the government.
  16. For preparation of dyes.

EVALUATION

  1. What is floriculture?
  2. List seven uses of ornamental plants.

COMMON SPECIES OF ORNAMENTAL TREES, SHRUBS AND FLOWERS

  1. ORNAMENTAL TREES
  2. Frangi pani
  3. Neem cassia
  4. Royal palm
  5. Balsam
  6. Flame of forest
  7. India almond
  8. Casuarinas
  9. Delonix
  • ORNAMENTAL SHRUBS
  • Allamanda
  • Crotons
  • Ixora
  • Cauliflower
  • Acalypha
  • Hibiscus
  • Wild rose
  • Bougainvillea
  • Zinnia
  • Dutchman’s pipe
  • ORNAMENTAL FLOWERS
  • Justicia
  • Cana lily
  • Morning glory
  • Crotalaria
  • Water lettuce
  • Lantana
  • Sun flower
  • Marigold
  • Commelina
  • Clitoria

CULTIVATION OF ORNAMENTAL PLANTS

The cultivation of ornamental flower includes:

  1. Selection of site that is well drained and easily accessible.
  2. Choice of planting materials which can be seeds or vegetative parts such as stems, roots, leaves (e.g bryophylum) and stolons
  3. Methods of cultivation
  4. Use of prepared bed
  5. Direct sowing to the soil
  6. Use of nylon bag
  7. Use of pots
  8. Provision of shades
  9. Organic manuring
  10. Regular weeding
  11. Regular watering

EVALUATION

  1. List two each of ornamental shrubs, trees and flowers
  2. List three propagative material in cultivating flowers.

SOURCES OF PLANTING MATERIALS

The planting materials such as seeds, cut stems, leaves, stolons or rhizomes can be obtained from;

  1. Established private horticultural gardens
  2. Higher institution botanical garden
  3. Government owned horticultural centres
  4. Private houses and offices
  5. Imported ornamental trees and flowers
  6. Resort or recreational centres

MAINTENANCE OF HORTICULTURAL PLANTS/FLOWERS

  1. Provision of shades
  2. Regular watering
  3. Regular weeding
  4. Fertilizer application
  5. Fencing
  6. Regular pruning

GENERAL EVALUATION

  1. What are ornamental plants?
  2. List five examples of ornamental flowers
  3. List five examples of ornamental shrubs
  4. List five uses of ornamental plants
  5. Explain five maintenance practice in planting of ornamental crops.

READING ASSIGNMENT

Revision questions 5 and 6 in Essential Agricultural Science for Senior Secondary Schools Chapter 25, page 236

WEEKEND ASSIGNMENT

SECTION A

  1. The following are ornamental trees except _____. A. frangi poni B.balsam C. royal palm D. ixora
  2. Which of the following is not an ornamental shrubs? A. allamenda B.crotons C. hibiscus D.casuarinas
  3. The following are ornamental flowers except ____. A.justicia B. carnalityC. crotalaria D. balsam
  4. The following are legumes except ______. A. centro B. stylo C. calapo D. panicum maximum
  5. ______ are cultivated purposedly for feeding animals. A. arable crops B. ornamental crops C. forage crops D. farm trees

SECTION B

  1. A. What is Floriculture

B. State four ways in which ornamental plants is beneficial to man

2.   A. List eight species of ornamental

B. State five effects of deforestation on the environment

WEEK: FIVE AND SIX                                                                                          Date: __________

TOPIC: DISEASES OF CROPS

CONTENT

  • Meaning and causes of diseases
  • Details of selected diseases

MEANING AND CAUSES OF DISEASE

A crop is a plant cultivated by man for a specific purpose. A plant disease is a deviation of the plant from the normal state of health, presenting outward visible signs. Diseases are caused by pathogens and enhanced by some physiological factors.

CAUSES OF DISEASE

Plant diseases are caused by pathogens. Pathogens are disease causing organism which passes through a regular cycle of development and reproduction. Examples of pathogens that cause plant disease are viruses, bacteria, fungi, parasitic worms and rarely protozoa. Some of these pathogens are carried by vectors and other agents.

Physiological factors such as nutrient deficiency in the soil, heat, presence of inorganic salts in the soil and soil moisture content has a major role to play in influencing plant susceptibility to diseases.

SELECTED DISEASE OF CROPS

NameCasual organismMethod of transmissionSymptoms and economic importancePrevention and control measure
Maize SmutFungus (Ustilago maydis)Fungus spores deposited on fruitsReduced yieldGalls on ears, leaves and tarsels which later turn blackDestroy diseased plant.Use resistant varieties.Seed treatment.
Rice BlightFungus (Piricularia oryzae)Airborne spores on leavesSmall longitudinal red spots on leaves which turn grey or brownReduced yieldUse clean seedsAvoid heavy use of nitrogen fertilizers. Use resistant varieties
Maize RustFungus (Puccinis polysora)Airborne spores deposited on leavesRed spots on leave.Reduced yieldDeath of crop.Early plantingCrop rotation Use resistant varieties.
Cercopora  a Leaf spot of CowpeaFungusThrough WindReddish brown spots on leavesLesions on leavesChlorosisDropping or falling of leaves.Spray with fungicidesCrop rotationPlant resistant varieties.
Rosette disease of  GroundnutVirusBy piercing and sucking insect (Aphid)Yellow leaves with mosaic mottling. Stunted plant with curled leaves.Wilting and death of plant.Shortening of the internodes.Early plantingCrop rotationUse insecticidesUproot and burn infected plants.Use resistant variety.
Cassava MosaicVirusThrough piercing and sucking insect (whitefly)   (Bemisia nigerensis)    Infected plant cutting  Mottling of leaves or leaf curlDistortion of leaves and stems.Vein clearingStunted growth Development of yellowish pale areas alternating with green patches on the leaves or mosaic pattern on the leavesUse resistant varietiesUproot and burn infected plant Spray with insecticide to kill vectorUse disease-free stem cuttings  Farm sanitation.
Leaf blight of CassavaBacterium Xanthomonas manihotisInfected     cuttingsRain splashingInsectsToolsBlighting of leaves Wilting of plantFalling off of leavesReduced yieldCabker of stemDie-back of stemUse resistant varietiesUse disease free cuttingsEarly plantingPractise crop rotation
Cocoa black pod diseaseFungus Phytophthora palmivoraRain splashInsectsBrown spots on podRottening of podsEntire pod turns black Low yieldRemove and destroy infected podsRegular weedingSpray with fungicides eg Bordeaux mixtureAvoid over crowding of cocoa plants.
Coffee Leaf rustFungusBy windBy rain splashYellow or brown spot on leavesOrange powdery mass on the leafReduction in yieldDropping of leavesPlant seeds from healthy plants Use resistant varieties.Spray with copper fungicides.
Black arm (bacterial Blight of cotton)BacteriumThrough leavesStems near the groundAngular spot on leavesBoll rotExudates from affected leavesRetarded growth and death of plant.Seed dressingUproot and burn infected plants
Root Knot of   Tomatoes/ OkraNematodesNematodes in soilKnotting or galling of rootsRetarded growth   Early death of plantReduction in yieldSoil sterilizationCrop rotationUse resistant varietiesUproot and burn infected plants
Damping off Disease of OkraFungusInfected soilRetarded growthCells become water loggedGradual wilting of plantDeath of plantSpray with copper fungicideUse resistant varieties Sterilization of soil
Onion Twister DiseaseFungusInfected soilWater splashInfected bulbTwisting of leavesGrey patches on leavesReduction in yieldDeath of plantCrop rotationUse resistant varietiesSpray with fungicidesEarly planting
Stored produce mould fungicidesFungusInfected seeds or fruits.High humidityBy SoilBlack mould on seeds and fruitsPungent smell.Sour tasteDecay of seeds and fruits in store.Proper drying of seed before storageSpray with Maintain low humidity in storeRemove contaminated seeds before storage.

EVALUATION

  1. What is plant disease?
  2. List four common disease causing organisms.

GENERAL EFFECTS OF DISEASE ON CROP PRODUCTION

  1. Disease generally reduce the yield of crops
  2. They reduce the quality of crops
  3. They can cause malformation of parts of plants
  4. They can kill or cause death of a whole plant
  5. They cause reduction in the income of a farmer

WAYS BY WHICH DISEASE SPREADS ON CROP FARM

  1. By rain splash
  2. Through the use of contaminated equipment
  3. The use of infected planting materials
  4. Wind blowing pathogens to other crops
  5. Through animals
  6. Through insect vectors
  7. Through visitors to the farm
  8. Through weeds

GENERAL CONTROL OF CROP PLANT DISEASES

  1. Cultural method: the use of crop rotation, planting of resistant varieties, tillage practice, regular weeding, pruning etc. to control or prevent disease
  2. Biological control: this is the use of the natural enemy of the disease to reduce  or totally eliminate the disease
  3. Chemical control: this involves the use of pesticides such as fungicides, nematicides, insecticides to prevent disease or control disease.

GENERAL EVALUATION

  1. What are pathogens?
  2. List two examples of pathogens.
  3. List three physiological factors that makes plants susceptible to diseases.
  4. List five air borne disease of crops.

READING ASSIGNMENT

Revision question 6 and 9 in Essential Agricultural Science for Senior Secondary Schools by O. A Iwena chapter 26, page 247.

WEEKEND ASSIGNMENT

SECTION A

  1. The following are pathogens except _____. A. viruses B. bacteria C. fungi D. algae
  2. Maize rust is caused by ______. A. bacteria B. fungi C. virus D. nematodes
  3. Rosette disease of groundnut is caused by ____. A. fungus B. virus C. bacteria D. nematodes
  4. Cocoa blackpod disease is caused by ______. A. virus B. bacteria C. fungi D. nematodes
  5. Root knoll of tomato is caused by ______. A. nematode B. fungus C. bacteria D.virus

SECTION B

  1. A. What is disease?

B. List disease pathogens

2    Discuss briefly the cassava mosaic disease under the following headings

A. Casual organism B. Transmission C. Symptoms D. Control

WEEK SEVEN AND EIGHT                                                                                 DATE: _________

TOPIC: PESTS OF CROPS

CONTENT

  • Meaning of crop pest
  • Types of crop pest
  • Classification of insect pest

MEANING OF CROP PEST

A crop pest can be defined as any organism capable of causing damage to the crop.

TYPES OF CROP PEST

Important crop pest are grouped in to the following classes;

  1. Insects
  2. Birds
  3. Rodents
  4. Monkeys
  5. Man
  6. Nematodes

CLASSIFICATION OF INSECT PEST

  1. Biting and chewing insects: they possess strong mandible and maxillae (mouth parts) which enable them to bite and chew plant parts e.g termites, grasshoppers, leafworm, mantids, locusts and beetles.
  2. Piercing and sucking insects: they possess stong mouthparts called proboscis which enable them to pierce through plants and suck liquid materials from them. Examples are aphids, cotton strainers, mealy bugs, scale insects, capsids, mirids and white flies.
  3. Burrowing insects: they and their larva stage are capable of burrowing the tissue of the plant parts or fruits or seeds. Examples are bean beetles, stem borers, maize weevils and rice weevils.

EVALUATION

  1. What are crop pests?
  2. List the three classes of insect pests.

IMPORTANT PESTS OF MAJOR CROPS

PestCrops AttackedNatures of Damages and Economic ImportancePrevention and Control Measures
Stem burrowerCereals e.g. rice, maize, guinea corn.Larvae bore holes into stemsThey eat up the tissuesThey weaken the plantUproot and burn infected plantSpray with insecticides e.g. Gammalin 20 Reduced growth and yieldEarly planting Crop rotation
Army WormCereals e.g. maizeLarvae invade and eat up leaves and stemReduce photosynthesisRetarded growthReduced yieldHand pickingSpray with insecticides. E.g. DDT  
Pod burrowerLegumes e.g. cowpea, soyabeansLarvae bore into the podThey eat up the seedsReduced yieldCrop rotationEarly harvesting  Spray with insecticidesIntroduce diseases.
AphidsLegumes e.g. cowpea, soyabeansStunted growthGalls on leavesVectors of disease e.g. rosette, mosaic disease of cowpeaSpray with insecticides to kill vectorUproot and burn infected plant  
Leaf beetleLegumes e.g. cowpea, soyabeansThey eat up the leavesReduce photosynthesisReduced yieldSpray with insecticidesUse pest-resistant varieties.
Cocoa mirids (capsids)Beverages e.g. CocoaThey inject toxic saliva into plantTransmits fungal diseasesReduced yieldStunted growthSpray with insecticides e.g. Gammalin 20Regular Weeding
Yam beetlesTubers e.g yamBoreholes into yam tubersReduced yieldReduction in quality and market valueDust yam setts with Adrin dust before plantingCrop rotation
Cassava MealybugsTubers e.g cassavaTwisting of stem and reduced internodesSwelling of shootsReduced yieldEarly planting Use pest-resistant varieties.Cutting treatmentSpray with insecticides
Green SpidermiteTubers e.g cassavaThey feed on the leavesReduce rate of photosynthesisReduced yieldUse biological controlSpray with insecticides
Variegated GrasshopperTubers e.g Cassava, yamAdults and larvae eat up the leaves and stemReduce the rate of photosynthesisReduced growthReduced yieldHand pickingSpray with insecticides e.g. Adrex 40
Cotton StainerCottonThey pierce and suck sap from plantsProduce toxic salivaTransmit diseasesReduce quality of boll Leaf distortionHand pickingSpray with insecticides
Cotton bollwormCottonLarvae feeds on the seeds of cottonCrop rotationDestroy the lint and reduce its qualityPremature fall of cotton bollSpray with insecticides to kill insectsBurn cotton plant debris after harvesting.
ThripsVegetables e.g. Onion, tomatoBrowning of leavesWilting of plantReduced yieldSpray with insecticides
Leaf rollersVegetableRolling and twisting of leaves Reduction in rate of photosynthesisReduced yieldSpray with insecticides e.g. Vetox 85
Leaf beetleVegetables e.g. pepper, okra and tomatoThey eat up leaves and stemsReduced photosynthesis Reduction in yield and qualitySpray with appropriate insecticides e.g. Vetox 85
Bean beetle, grain weevilsStored produce e.g. rice, cowpea and maize.Boreholes into grains and eat them upReduce the quality of stored produceReduced farmer’s incomeReduce the market value of grainsReduce viability of insfested grainsEarly harvestingProper storage of produceProper cleaning and fumigation of store with phostoxin tablets or with lindane dust.Store grains over fire placesProper drying of seeds to reduce moisture content and kill the eggs and larva of pests.
BirdsRice, maize, millets and sorghumFeed on grains in the fieldReduction in quality and yieldReduction in income of farmersUse of bird scarer or scare crowUse of cage traps with baitsShooting with catapultDrumming or noise making on the farmUse of explosive mechanism at regular intervalsUse of avicidesFencing /Screening farms in greenhouse
Rodents e.g. bush rabbit, rats and squirrelRice, yam, cassava and fruitsThey feed on cropsDestroy whole plantReduction in yieldIncrease in cost of productionTrapping with braits.Use of rodenticidesUse of string/wire trapsUse of predators e.g. dogs and catsClean weeding of farmsShooting and fencing Use of pit traps
MonkeysCocoa mango, banana, and orangeThey eat up the fruits Reduce the quality of fruitsLosses to the farmerUse trapsShooting with gun where possible.

EVALUATION

  1. List two ways of controlling cocoa mirids
  2. List two ways of controlling monkeys

ECONOMIC IMPORTANCE OF INSECT PESTS IN CROP PRODUCTION

  1. They destroy crops in the fields through their biting, chewing, boring, sucking and defoliation activities.
  2. They cause reduction in viability of stored produce
  3. Spot of injuries by insect pests predispose crops to pathogen attack
  4. They increase the cost of production as they are being controlled
  5. They render vegetables and fruits unattractive and unmarketable
  6. Some are of vectors of disease
  7. The profits of farmers are reduced
  8. They reduce the quality of produce either in the store or in the field
  9. They generally reduce the yield of crops
  10. They can also cause total death of crop plants.

GENERAL EVALUATION

  1. What are pathogens?
  2. List five pathogens you know
  3. List four economic importance of insect pest

READING ASSIGNMENT

Revision questions 3 and 8 Essential Agricultural Science for Senior Secondary Schools Chapter 26, page 247

WEEKEND ASSIGNMENT

SECTION A

  1. _____ is responsible for damages in crops. A. weeds B. water C. air D. pests
  2. The following are rodents except _____. ?A. rat B. grasscutter C.squirrel D.monkey
  3. The following are bitting and chewing insect except ____. A. termites B. capsids C.locust  D. beetles
  4. Stem burrowers will attack A. cereals B. legumes C. tubers D. spices
  5. Cotton strainers and meleabugs are examples of _____ insects. A. biting B. chewing C. piercing D. burrowing

SECTION B

  1. A. What are pests

B. List the five types of pests

2.   A. List five effects of pests in crop production

B. List three control measures of plant disease

WEEK NINE                                                                                                            DATE: _________

TOPIC: GENERAL PREVENTION AND CONTROL OF CROP PESTS

CONTENT

  • Physical control
  • Chemical control
  • Biological control
  • Cultural control

METHODS OF PEST CONTROL

Crop pests can be prevented or controlled through the following methods:

  1. Physical control
  2. Cultural control
  3. Biological control
  4. Chemical control

PHYSICAL CONTROL

This involves the physical removal of pests by:

  1. Hand picking of insects and larvae
  2. Setting traps to catch rodents
  3. Shooting rodents with gun
  4. Fencing round the farm with wire nets.
  5. Use of scarecrow.

EVALUATION

  1. List the methods of pest control
  2. List three ways by which pests can be removed physically

CULTURAL CONTROL

This method involves the use of farm practices to prevent or control pests, examples of cultural control are:

  1. Practicing crop rotation
  2. Use of pest resistant varieties of crops
  3. Appropriate tillage operations
  4. Burning crop residues
  5. Timely planting of crops
  6. Proper weeding or sanitation
  7. Timely harvesting
  8. Close season practices (no living plant is allowed for a certain period).

BIOLOGICAL CONTROL

This involves the introduction of natural enemies of pests to control or keep the pests population under control. Such enemies eat up or feed on these pests, thereby reduce the population of the pests.

EVALUATION

  1. List two cultural control of pests
  2. Explain biological pest control

CHEMICAL CONTROL

This involves the use of chemical called pesticides to control pest of crop plants. Examples of pesticides are insecticide, rodenticide, avicide etc.

Examples of chemicals used to control pests are:

  1. Insecticides – for controlling insect pest e.g grasshopper
  2. Rodenticides – chemical control for rodents such as rats
  3. Avicides – for controlling bird pest
  4. Nematicides – chemical used to control nematodes. E.g worms

FORMS OR GROUPS OF INSECTICIDES

The four groups and the mode of action are:

GroupMode of action
PowderContact
LiquidSystemic
GranulesStomach (Ingestion)
GasFumigation

SIDE EFFECT OF THE VARIOUS PREVENTIVE AND CONTROL METHOD OF DISEASE AND PEST OF CROPS

Use of these control methods have their effect, these effects includes

  1. Death of some beneficial insect and soil organism, toxic exposure to animals and man, chemical residue in the environment, washing away of chemicals into aquatic life e.t.c when chemical control method is employed.
  2. Organisms introduced may attack cultivated crops or stored grains, predators might not feed on targeted pest and deviate to feeding on beneficial organisms, the activities of new organism might cause an ecosystem imbalance when biological control method is employed.
  3. When cultural control method is employed, the use of bush burning method might get out of hand thereby destroying soil structure, spread to other farms, loss of organic matter and lead to death of beneficial microbes.

GENERAL EVALUATION

  1. What are insecticides?
  2. List the three forms of insecticides and their mode of action
  3. What are avicides, rodenticide and nematicides are used to control
  4. List five economic importance of crop pests.

READING ASSIGNMENT

Revision question 10, 14 and 16 Essential agricultural science for senior secondary schools chapter 26, pages 247-248.

WEEKEND ASSIGNMENT

SECTION A

  1. Avicides are used to control _____. A. rodents B. birds C. insects D. pests
  2. The mode of action of liquid insecticide is_____. A. contact B. systemic C. stomach D. fumigation
  3. Weevils are _____ insects. A. biting B. chewing C. burrowing D. piercing
  4. The following are pests except. A. rodents B. earthworm C. monkeys D. nematodes
  5. The following are biting chewing insects except _____. A. butterfly B. locust C. grasshopper D. cricket

SECTION B

List two side effects each of using

  1. Cultural control of pests
  2. Biological control of pests
  3. Chemical control of pests
  4. Physical control of pests

WEEK TEN

REVISION

WEEL ELEVEN

EXAMINATION

Leave a Reply

Your email address will not be published. Required fields are marked *