THEME 3.0: CROP PRODUCTION
Introduction to crops science and production
There are many 350,000 known species of plants in the work but relatively few of these have been used.
Those plants which have been identified, domesticated and cultivated are called crops.
Origin of crop plants
There is archaeological evidence that crop production dates back to 9000-7000 BC in both the Middle East and South America.
Definition
Crop plants: Are plants grown by farmer for economic importance.
Crop science: Is the study and use of scientific method to rise or grow crop plants. Crop production: Is the growing of crop plants for food and other purpose. Classification of crop plants grown in Tanzania.
(a) Agronomic classification:
Crops are grouped according to their various products. The crops belong to definite botanical families.
Cereal crops or grain crops –maize, paddy.
Grain legumes or pulses-groundnuts, cow peas.
Tuber crops.
Root crops.
Fruit crops.
Sugar crops.
Oil crops- simsim, soya beans, cashew nut, and sunflower.
Vegetable crops – cabbage, okra, lettuce, tomatoes
Forage crops – guinea grass, Rhodes grass, elephant grass
Medicinal and drug crops – tobacco, pyrethrum
Ornamental – Hibiscus, Bougainvillea & Roses
Fiber crops – are crops which contain fibers in the leave, stem, and bear fiber on their seeds
Fibers on seeds – are cotton and kapok
Fibers on leaves – sisal
Fibers on stem – hemp, jute and kenaf
Cereal crop or grain crops
These are members of the grass family. All of them are annual crops
Characteristic of cereal crops
Bear seeds which are called grains (grain crops)
Have long leave with parallel vein
Are annual crops
Have fibrous roots
Examples of cereal crops
Maize, paddy, bulrush millet, sorghum, millet, wheat and barley (shahiri)
Oil Crops
Are crops which bear seeds / fruit which contain oil. Most of them are annuals – others are perennials
Examples: groundnuts, sunflower, cotton, simsim, soya bean, castor, cashew nuts, sunflower and coconuts.
Fiber crops
Are crops which contain fibers in the stem or bear fibers on their seeds
Examples: Cotton, kapok, sisal, hemp and kenaf
Which bear fibers on the seed – cotton and kapok
Which produces fibers in the leaves sisal
Which produce fibers on stem, hemp, jute and kenaf
Beverage crops
Beverage crops produce fruit or leaves which are used for making refreshment drinks (beverages)
Example: Coffee, tea and cocoa
Legumes
Are crops which produce fruits with a carpel that splits along the edges. Legume contain large of protein. Bear seeds with a large amount of oil as well. Examples: Haricot beans, cow peas, grams, groundnuts, pigeon peas, and bonavist beans
Root crops
Are crops which store food reserves either in the roots e.g. cassava and sweet potatoes or on the bottom parts of the stem e.g. potatoes.
Examples: Cassava, potatoes, sweet potatoes and yams.
Fruits crops
Are crops which bear fruit which can be eaten in a raw state when ripe.
Examples: Citrus (oranges, tangerine and lime), pawpaw, pineapples, pears, apples, peaches, vines and plums.
Medicinal crops
Are crops that contain toxic or curative substance which are beneficial to human being.
Examples: pyrethrum, tobacco, cinchona and cloves
Spice crops
Spice crops produce fruits, flower or barks which are used by human beings to improve the taste and / or aroma of food
Examples pepper, cloves, cardamom, cinnamon and ginger.
Vegetable crops
Vegetable crops are grown for use as vegetable.
Examples: Tomatoes, onions, cabbage, okra, leak, lettuce, radish, cauliflower and egg plant.
Forage crops
Are crops grown for feeding livestock especially cattle, goat and sheep
Examples: Guinea grass, Rhodes grass, elephant grass and legumes (Lucine, stylo, clovers, and Centro.
Ornamental
Are plants which are grown for decorative purpose such plants producing leaves or flower which has attractive colours.
Examples: Hibiscus, Bougainvillea and roses
Others special crops
Sugarcane – for making sugar
Tobacco – for making cigarettes
(b) Morphological classification
This is a way of classification done according to the seed Morphology in terms of Cotyledons.
(i) Monocotyledons: are crops whose seed have only one cotyledon
Characteristic
Narrow long leaves with parallel veins
Fibrous not system
One cotyledon
Example: Cereals e.g. maize, sorghum, millet etc
(ii) Dicotyledons: are crop with two (2) cotyledons
Characteristic
2 cotyledons
Broad leaved with net vein
Tap not
Example: legume e.g. beans, peas, groundnuts etc
(c) Classification according to life cycle
This classifies crops according to duration spent in the field with regard to life cycle of the plant.
(i) Annual crop
Are crops which complete their life cycle within one season (year) e.g. Beans, Peas, Potatoes
(ii) Biannual crops
This are crops whose life cycle is completed within two seasons (years), most of the vegetable e.g. onions, cabbage, etc
(iii) Perennial crops:
These are crops whose life cycle is completed more than one year e.g. coffee, tea, banana
(d) Use classification
This is a way of classification done according to their use or purpose
(i) Food crops: are crop plant grown for food
Examples: Cereal crops, legume etc
(ii) Cash crop plants, are crop plants grown for sale; Examples coffee, tobacco, pyrethrum, tea etc
(e) Vavilov’s classification
Classify crops according to their origin;
Examples
Southwest Asia – barley, carrot, date palms, grapes, melon, wheat
Mediterranean – Cabbage, clover, hops, lettuce, oats, olive
Ethiopia – castor, coffee, finger millet, okra, sorghum, wheat, cow peas, cotton
Central – Apples, fox tail millet, hemp
S. East Asia – Bamboo, banana, Chinese yam, citrus, coconut, Coconut sugarcane
Indo-Burmese – Coco yam, cotton, garden egg, jute, mango pigeon pea, Rice
Chinese – Onion, orange, soya bean, peach, tea
W. Central Africa – Barbara groundnut, coffee, kola, cow pea, sorghum, Oil palm, red rice, yam
C. America, Mexico – Guava, kidney bean, maize, red pepper, sisal, up land Cotton
Ecuador palm – Avocado, peer, potato, pawpaw, sea bland cotton,Sweet potatoes, tobacco, tomato
Brazil, Paraguay – Cashew, cassava, cocoa, groundnut, pineapple, Rubber
Knowledge of the origin of a crop enables plant breeders Identity diverse forms of the species from which useful traits or characters can be obtained for use in crop improvement programmers.
DISTRIBUTION OF MAJOR CROP PLANTS OF ECONOMIC IMPORTANCE IN TANZANIA
FACTORS AFFECTING CROP PRODUCTION IN TANZANIA
There are five groups of factors which affect crop production in Tanzania. Those groups of factors are as follows;
a) Climatic factors
b) Edaphic factors
c) Biotic factors
d) Economic factors
e) Social factors
A. Climatic factors
The include temperature, rainfall, humidity, atmosphere pressure, wind direction and strength, sunshine and cloud cover. They are generally known as the elements of the weather.
Temperature
Depend mainly on the altitude of that area. Generally highland areas here lower temp, than lowland areas. (Threshold temp. minimum temp required)
Some crops grow well in areas with low temperatures others grow well in areas with medium or high temperature.
Rainfall
On the basis of their water requirements, plants are divided into three groups
Xerophytes
Are plants which grow well in very little moisture in the soil, they are also called drought-resistant plants.
Examples: Sisal, cassava and sweet potatoes
Hydrophytes
Are plants which grow well only in plenty of water in the soil. Example: Low land paddy
Mesophytes
Are plants which grow well only when there is neither too much water nor too little in the soil.
Examples: Maize, beans and cotton
Humidity
High atmospheric water vapour (humid), plant does not lose water easily through transpiration, hence ennglish-swahili/courage” target=”_blank”>courages the development of fungus plant disease. Low humidity, retards the development of fungus plant disease, it also increase the rate of transpiration
Sunlight
Affects flowering in plants, the length of time during which plants are exposed to sunlight each day is called the Photo period
Some plants required exposure to long period of sunlight per day (long-day plants) in order to flower. Other require exposure for short periods each day ( short day plants)
Wind
Affects the growth of plants. When plants are exposed to wind, they lose a lot of water through transpiration. Strong winds may also push down plants or break their branches to control strong wind it is necessary to provide (wind breaks).
B. Edaphic factors
Are characteristics of the soil, roots of plant grow in the soil, they absorb nutrient and water, for good plant growth soil must supply an adequate amount of nutrient, moisture and soil reaction or pH of the soil must be optimum as well as air supply.
C. Biotic factors
The growth of crop plants is affected by biological organisms. Insect nests and vermin attack crops and lower the yield. Plant disease also affects the growth and yield of crops plants. Weeds are plants which grow in a place where they are not wanted. They complete with crop plants for rooting space, nutrients and moisture.
D. Economic Factors
Most of the peasant farmers in Tanzania do not have enough money to buy inputs required for crop production e.g. cultivation equipments, such as ox-ploughs, fertilizer, improved seeds, pesticides and crop processing equipments.
Most of the rural areas of Tanzania here poor communications making nglish-swahili/distribution” target=”_blank”>distribution of input and transportation of products difficult.
E. Social factors
Most of the peasants in Tanzania do not possess good agricultural – know how. When some peasants are advised by agricultural extension agents on good forming practices, they do not easily adopt them for fear of risk.
Sometimes the farmers and their families are weak because they do not eat nutrition’s food. Diseases and parasites also affect their health.
REMEDIAL MEASURES
Climatic and edaphic factors
(a) Mulching: Covering of soil surface with organic material to prevent
Evaporation looses and improves soil moisture and temperature.
(b) Fertilizer / Manure application to improve soil fertility
(c) Tillage: frequent land tillage will help plant roots penetration and improve Soil aeration.
(d) Liming:
Is the application of liming material (CaCo3), MgCo3) to acidic soil so as to bring soil into reasonable (PH) for plant growing. Describe level of soil (PH5-7.5) fertilizer may be used to raise soil acidity such as SA and CAN.
(e) Wind break
Tree can be planted around the farm to reduce the wind velocity so as to control wind effects.
(f) Irrigation
Watering of plants field in areas of low rainfall supply to reduce drought effects.
Biological factors
Field hygiene by proper and timely weeding, pest and disease control should be done as early as possible to reduce their effects on crops production.
Social economic factors
Provision of loan to enable farmers to have capital to invest in crop production.
Agriculture education – to improve extensions services so as to enable farmers to obtain skill and proper management practices in crop production.
Developments of research centre; to facilitate improvement of crop production through improve seeds, tools and management practices.
FARMING SYSTEM
Meaning of the concept: – This refers to the practices systems by which crops livestock can be used by farmers.
TYPES: There are three types
o Crop farming system
o Livestock farming system
o Mixed farming system
CROP FARMING SYSTEM
This refers to ways under which crops are grown. There are three types of crop farming System.
Subsistence crop farming: This is farming system whereby farmers produce food crops
Essentially for home consumption and surplus. Is either
Selling is done to meet domestic demands e.g. sugar, fuel etc.
Characteristic features of subsistence farming
Dependence on family labor: Subsistence farming activities e.g. Cultivation, weeding and harvesting.
Use simple technology: Farmers adopt simple farming technology to produce family food. Use of hand hoes axes, forked hoe. Ox – plough if available is practiced
Small farm size: Fields are usually small less than far family. The farms are usually fragmentary into small pieces for growing different. food crops.
Standard of living: In subsistence farming areas, the standard of living of most farmers is very how.
Important services such as transport, communication and developed market infrastructure are lacking.
Poor method of farming method Inter cropping is a common practices in subsistence Agriculture, even though yields are always low due to poor techniques.
Dependence on areas as food crops.
Important crop crops grown in this system is largely cereals, maize, sorghum, millet paddy, as well as not crops, and groundnuts and bananas.
ADVANTAGES OF SUBSTANCE FARMING.
• Many crops can be grown
• Control protect soil fertile due to many crop grown in one area inter cropping
• Production for hone consumption serves transport and marketing.
• Food sufficiency for domestic and local demands
• Farmers are kept independent of the market
• It is more adaptable to price fluctuation.
Disadvantages of substance farming
• Small scale production tend to keep farmers poor
• Difficult to provide extension services as farmers are scattered
• Labor becomes redundant between harvesting and planting time when there is nothing to do.
• As more labor and other units of Inputs are added to increase output. yields always become low (the setting of law. of law of diminishing returns
• Low economic development due to low investment survival of the farms is threatened by extent. of crop failure since they reduce small samples over and above the family nutritional requirement
Arable farming: This is the growing of short term crops in arable land where animal crops are grown.
• Can either be practiced by shifting or salted utilization system.
Characteristic feature of Arable farming.
• Large scale field of about 1- 1oo hectare. With animal crop like wheat, barley plantation.
• Uses Improved tools, seeds, fertilizers, Chemical as well
Characteristic feature of Arable farming.
• Large scale field of about 1-100 hectare with annual crops like wheat, barley plantations.
• Uses Improved tools, seeds, fertilizers, chemical as well
Characteristic feature of arable farming
- Large scale field of about 1-100 hectare with annual crops like wheat, barley plantations
- Use improved tools seeds, fertilizers, Chemical as well as ox power or tractor power
- Crop rotation system practiced to allow replenishment of soil fertility
- Crook crop husbandry.
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Advantages of Arable farming system
• Supply enough food for the society nation
• Help to Improve and maintain land soil fertility
• High saving is achieved due to high income gained
• Both cash and food crops plants are produced thus supplying raw materials to local industries
• Foreign exchange earner
• It helps to more population to get involved in agriculture.
Disadvantages of arable farming system
• Need large area of land (1-100hectare)
• High capital Investment for buying input and Machinery
• Need skilled labor to operate the project
• It depended mainly on rainfall, as poor Weather causes great loss
Commercial crop farming it involves growing of crop for commercial purposes either
Small or large scale production
ADVANTAGES OF COMMERCIAL FARMING
• It generates foreign money in the country from the selling or exporting leading crops e.g. coffee, tea sisal.
• Create employment opportunity through local Industries which uses raw materials from crops grown.
• Make use of poor marginal areas with scare rainfall not stuffiest to support meaningful crop farming.
CROPPING SYSTEMS AND PLANTING PATTERN
Various cropping system are used by farm grow their crops, using various patters.
Cropping system: Is a combination of crops which are grown by farmers in a Particular season.
Planting pattern: Refer to the Method by which the crop are planted in the CROPPING SYSTEM.
(i) Monocroping;
Is a practice of growing one type of any annual crop on a field in seasons
(ii) Monoculture:
(Pure stand cropping) is the practice of growing the same crop on a particular field for a long period of time e.g. coffee, tea.
(iii) Advantages of (i) & (ii) systems
The system enable farmer to apply fully the recommended cultural practices because on type of crop is grown at a particular season.
Disadvantages of (i) and (ii)
o Risky system as only one crop is grown at a time; any crop failure due to bad weather, pest and diseases outbreak the farmer is likely to end up with poor harvest.
o Facilitates poor soil fertility due to continuous depletion of the martens by the same crop yearly thus resulting to low yield in subsequent seasons.
o Risk of increasing population of certain weeds pests and disease due to the effect of specific biological organisms to a particular hosting to low yield in subsequent seasons.
Crop rotation:
This is the process of growing different types of crops on the same piece of land in successive seasons or years.
Factors/Principles to be considered when planning a rotation
1) Feeding habit of plants,
There are some crops which utilize/absorb only a small quantity of nutrient (Light feeders) while others absorb a lot of nutrients (Heavy feeders)
Hence, if is advisable to interchange heavy feeder to light feeders when planning a rotation
2) Rooting system
Some plants have short fibrous roots which occupy mainly the upper surface of the soil (shallow rooted) while others are deep rooted (Deep rooted)
o To maximize benefit from the soil, it is advisable to alternate deep rooted with shallow rooted crops, when planning a rotation
3) Families
Plants of the same family members are attacked by the same disease microorganisms and pests. It is advisable to plant different families in successive seasons.
4) Growing habit
Different growing habits e.g. sweet potatoes, pumpkins, cover the soil fully than maize or sorghum thus surprising weeds. It’s advisable to include such plants in the rotation
5) Improvement of soil fertility, it is advisable to include leguminous plant in the rotation so as to improve soil fertility through nitrogen fixing bacteria.
Examples of crop rotation
(a)
(b)
|
Cycle |
Plot1 |
Plot2 |
Plot3 |
|
1stYear |
Cotton |
Beans |
Maize |
|
2ndYear |
Bean |
Maize |
Fallow |
|
3rdYear |
Maize |
Fallow |
Cotton |
|
4thYear |
Fallow |
Cotton |
Beans |
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Advantages
o Helps to control insect pests, diseases and weed
o Provides full utilization of soil nutrients by plants
o Improves soil fertility when legumes are inclusive
Interpolating
This is the practice of growing two or more types of crops at the same time / season.
Types
(i) Inter cropping
Is a practice whereby different crops which are planted at a specific and systematic pattern.
(i) Mixed cropping
Is a practice where by different types of crops grown are planted randomly in the field.
Advantages
o Roots of different crops grow fill up in the soil profile fully than only one type of crop is grown
o Shallow rooted crops absorb water and nutrient from the upper layer.
o Deep rooted absorb water and mineral from deep layers
o When leguminous crop include improves nitrate content in the soil
o Help to control soil erosion due to full soil coverage which protect the soil surface from water and wind erosion
o Ensures protection against crop failure i.e. when one crop fails a farmer can harvest other crops
Planting patterns
Farmers in different areas use different planting patterns
Types
(i) Broadcasting
(ii) Row planting
(iii) Drilling
(1) Broadcasting
This is a random scattering of seeds over the surface of the field
This can either be done by hand or machine i.e. Broadcaster
Seed covering in either a separate operation or not don at all
Disadvantages
Difficult to estimate seed rate
Seed coverage is poor
Other post planting operations e.g. weeding cannot be carried out
Sometimes thinning is require
(2) Row planting
This is a systematic planting of seeds in well spaced rows systematic distances
Can be done either by hand or machine (row planters)
Distance between rows is known as inter-row spacing
Distance between plants is known as intra-row spacing or within now spacing
(3) Seed drilling
This is a random dropping and covering of seed in furrow to give definite rows
Comparison between Broadcasting and Row planting
i. Broadcasting is used when growing close growing crops e.g. pasture grass, paddy, while row planting is used for widely spaced crops e.g. maize
ii. When row planting is used correct spacing can be done, thus optimum plant population is obtained leading to high yield
iii. It’s possible to do machinery operation like weeding, fertilizer application, spraying and harvesting when row planting is practiced, compared to broadcasting.
GENERAL PRINCIPLES OF FIELD CROP PRODUCTION
Major principles of crop production (annual crops) fall under two categories
(i) Pre-harvesting operations, these are practices or operation which are done before the crops reaches maturity and ready for harvesting.
(ii) Post-harvesting operation
Refers to all practices geared at the handling of the crops produce after harvesting
Pre-harvesting operation
The following practices or operations are inclusive
(a) Site selection:
A choice of a good site is important
o Site should have the following quality
o Well drained soils of good fertility
o Easily accessible for easy transportation of input and harvests
o Well protected from strong and vermin
(b) Land preparation; this involves the following operation
o Clearing of bush and removal of stamp
o Opening up the soil (i.e. tilling the land) by plowing
o Loosening of soil ambles (if machinery was by harrowing
o Removal and burning of trashes
(c) Planting
This involves the following
o Selection of suitable seed variety is suitable for planting in an area with preferred ecological condition. Select recommended for planting in your area
o Dressing of the seed if the seeds have not been dressed. This is done to control soil born diseases and pest-from attacking the seeds after planting.
o Selection of suitable planting time. Usually early planting is recommended to avoid pests and diseases as well as full utilization of early rains.
e.g. Sometime crops require dry weather at maturity e.g. legumes or wheat. To avoid unfavorable. Weather during maturity proper planting period should be selected.
For cotton, maize, sorghum, pyrethrum etc early planting is recommended to avoid low yields.
Weeding
To avoid competition of plant and weeds, timely weeding is essential. This can either be done by hand, machine or chemical (i.e. use of herbicide). The operation should be done when the plants are still young and tender
Fertilizer / Manure.
For increase in yield, use manure is very important; especially right after weeding. Application of suitable nitrogenous fertilizer e.g. SA, CAN and UREA according to recommendations of the ministry of Agriculture.
Thinning
This is the removal of excess / weak plants and leaves the required number of plants / heel to reduce competition as well as facilitate the recommended spacing for optimum yield.
Pruning
In such a crops like tobacco, where tips of Tobacco leave in the nursery are cut by sharp pruning tools to reduce speed of growth, to make stem strong as well as hardening off seedling for field condition.
Topping/Desuckering
(Tobacco) these operations are exercised in tobacco plant to get large leaves and desuckering is the removal of sucker from tobacco plant between stem and leaf. Preparation of storage unit / cribs
(j) Harvesting: The operation should be timely done, when the crop has reached its maximum maturity period.
– Proper handling of the crop during harvesting is quite essential.
– Harvesting equipments should be clean and dry to reduce risk of destroying the harvest.
– Quick transportation of the harvest from the field to homestead should be done to avoid theft and crop destruction by insects or untimely rain showers. Post harvest
Operations include the following:-
(a) Further Drying: Low moisture content especially in cereal crops facilitate long and safe storage. Further drying after harvesting is essential.
(b) Fumigation/Dressing: When the harvest is dry and to ensure safety in ware houses/stores, fumigation by spraying the produce before bagging and after or Dressing by dusting with storage chemicals can be done.
(c) Storage: This is the final operation. The following should be considered:
– Stores should be well ventilated to provide good aeration thus reduce insect multiplication.
– Windows should be protected with wire mash to control insects from entering.
– Bags should be stacked on raised pallets.
– The floor should be dry and protected from any water entrance.
– Frequent cleaning of the store should be done.
– Rodents should be well taken care of.
