biology of plant production assignment 1 sp 4 2002

8/8/2019 Biology of Plant Production Assignment 1 SP 4 2002

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Table of Contents

Page 3 Introduction

Page 3 What is Wheat?

Page 4 Physical Description of wheat plant

Page 5 Description of wheat grain

Page 6 Production of wheat

Page 7 Climate

Page 7 Soil

Page 8 Sowing

Page 8 Weeds, Pests and Diseases

Page 9 Harvesting

Page 9 Changes by Cultivation

Page 9 Wheat Yields

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Assignment 1

Introduction

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For this assignment, I have chosen wheat as the subject.

What is wheat?

Wheat is a cereal grain belonging to the genus Triticum and is believed to been first

cultivated around 11,000 years ago in the area around the Tigris and EuphratesRivers. From there it was transported to many areas of the world and has becomeone of the most important foods covering more of the earth's surface than any other food crop.

The spread of wheat around the world was assisted by the spread of Europeancivilisation by explorers and colonists and this spread the grain to the Americas andAustralia, who are now among the major growers and exporters.

Wheat is a very versatile food, the kernels can be ground into flour to make breads, biscuits, cakes, spaghetti noodles and pasta. Other uses of wheat are for breakfastcereals, livestock feed, MSG (mono sodium glutamate to enhance other foodflavours), fertiliser, straw (made into hats or boxes), polishing metals and glass,adhesives and alcohol for fuel and for use in manufacturing synthetic rubber.

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Physical Description:

Wheat is a member of the grass family, a cereal and therefore an annual, whichrequires planting each year. When it is young it has a bright green colour and cangrow between 0.6m and 1.5m tall. Colour can vary from white to purple to red togolden brown at maturity depending on the variety.

http://worldbook.bigchalk.com

Wheat plants consists of the following parts:

Roots:There are two types of roots, primary and secondary. Primary roots grow out from theseed and live for six to eight weeks and are replaced by secondary roots, which grow asthe stem begins to grow out of the soil. Secondary roots are thicker and stronger than

primary roots and anchor the plant to the soil. Depending on the soil type roots usually areconfined to the top 50cms of soil however in loose soils they can grow to 200cms belowthe surface.

Stems:The plant consists of a main stem is hollow and can have additional stalks called tillers.The head grows on the end of the main stem and tillers.

Leaves:The leaves consist of a sheath and a blade, the sheath wraps around the stem and the tiller.The blade is long flat and narrow and extends from the top of the sheath and is pointed atthe end.

Head:Also called a spike or ear, the head is formed at the top of the tiller or stem and is a many

jointed stem carrying clusters of flowers called spikelets which branch from each joint.The wheat flowers are small and non-coloured and look like dust on the head. They areself pollinating in most cases however the can also be pollinated by pollen being carried

on the wind.

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After pollination the grains fill out in the head with a milky white liquid which turns dryand hard when the crop is ready to harvest. On average a head will contain about 35 grains

but there can be as many as 50.

The wheat grain:

http://worldbook.bigchalk.com

The wheat grain is around 3mm to 9mm long and consists of the following:

Husk:

This is the protective outer coating and is removed by threshing and winnowing the grainand does not have any real commercial use apart from possibly stock feed and is usuallyleft behind after being processed by the harvester.

Bran:

Bran covers the surface of the kernel and consists of several layers making up about 14%of the grain. This is removed during milling and is in the production of foodstuffs.

Endosperm:

This is found inside the bran and makes up about 83% of the grain. It is essentially thefood source when the grain is planted and begins to grow before the root system becomeseffective. This is ground to make flour which is an important food source.

Wheatgerm:

Wheatgerm is the embryo of the new wheat plant and makes up about 3% of the grain. Itis also removed during milling and used in the production of foodstuffs.

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Production of wheat:

Wheat production in Australia is a major industry and represents 90% of total valueof grain production with an average turnover of $600,000,000 per annum. This isnot a high figure if compared to other world producers (about 3%of the total) but

due to Australia's limited domestic demand it amounts to between 8 and 15% of world trade. This makes Australia one of the largest exporters after the USA,Canada and on a par with the European Union.

World Wheat Production, Trade and Stocks1 in Millions of Tonnes

Country 1992-1993

1993-1994

1994-1995

1995-1996

1996-1997

1997-1998

1998-1999

1999-2000

2000-20013

Production - Producers (Major)

China 100.5 106.4 101 102.2 110.6 123.3 109.7 113.9 102

EC2 94.8 81.1 85.5 87.7 100 94.7 103.8 96.9 104.4

CIS 88.7 62.7 59.6 58.5 63.5 79.4 55.5 64.6 62.7

India 55.7 58.8 59 65.8 62.6 69.3 65.9 70.8 75.6

USA 66.9 65.4 63.2 59.5 62 67.5 69.4 62.7 60.5

Canada 29.9 27.2 23.2 25 29.8 24.3 24.1 26.9 26.8

Australia 16.2 16.9 9 17 23.7 19.4 22.1 25 21.2

Pakistan 15.7 18.2 15.2 17 18.9 18.7 18.7 17.9 21.1

Turkey 17.3 16.8 14.7 15.5 16.2 16.2 18.5 16.5 17.5

Argentina 9.7 9.2 11.3 9.5 15.9 14.8 11.5 15.3 16

Others 76 79.4 82.6 82.1 81.2 84.2 87.3 73.9 73.5

Total 561.4 558.1 524.3 540.6 582.4 286.5 586.5 584.4 581.3

Trade -Net Exporters (Major)

USA 37.1 32.9 32.4 33.6 26.5 29.8 29.8 29.8 28.5

Canada 21.6 18.2 21.3 17 17.9 14 14 18.4 17Australia 9.5 12.8 7.9 12.1 17.9 16.1 16.1 17.3 16.5

EC2 22.7 19.1 16.1 12.6 17 13.7 13.7 16.7 14.5

Argentina 7.3 4.5 7.9 4.4 10.3 8.9 8.9 10.8 11.5

Trade -

Net Importers (Major)

Egypt 6.2 5.9 8.2 6.1 6.9 7.4 7.4 6.2 6

Japan 5.9 6 5.7 5.9 6 5.7 5.7 6 5.6

Brazil 6.5 5.5 5.8 7.3 7.3 7.1 7.5

Iran 3.3 2.9 7.1 2.5 2.5 7.2 7

Pakistan 2 1.8 3.1 3.1 3.1 1.8 0.1

Indonesia 3.3 3.5 4.2 3.2 3.2 3.8 3.8

South Korea 4.1 2.4 3.4 5 5 3.8 3.5CIS 18.5 6.2 3.8 3.6 2.5 4.5 4.5 9 5.3

China 6.7 4.5 10.1 12.6 8 1.9 0.8 1 0.4

Stocks (Carryover) of Net Exporters

55 47.4 34.4 34.2 36.2 41 56.6 51.5 50.9

Source - International Grains Council September 1998 reproduced from www.awb.com.au

1 June - July years includes flour and durum wheat. Countries listed in order of magnitude 1997-1998

2 Fifteen member states. Excludes intra EU trade, exports under "inward" processing arrangements and shipments of product other than wheat flour

3. Estimate

4. Forecast.

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Production of wheat began thousands of years ago and in some parts of the worldthe similar methods are probably still used, tilling the soil by hand or with theassistance of domesticated animals, hand planting of seeds and harvesting by handon relatively small parcels of land. In other areas of the world, the whole cycle iscompleted by machinery using broad acre farming methods.

In both instances there are several factors which are the same:- good soil, regular rainfall, disease free seeds and planting and harvesting at the right times.

Map showing the main growing areas in Australia - www.awb.com.au

Climate:

Relatively dry and mild climates are the best for growing wheat, and in Australiathe best growing season is between May and October. Wheat needs between280mm and 380 mm of rain at the right times to assist in the growing cycles, toomuch at the harvesting time can destroy the crop, too little in the beginning and theseeds will not grow. The rain also needs to be retained by the soil to provide water during the drier periods.

Temperature is also important, too hot and the wheat can dry out not produce thequantities required to make it viable and too cold and the young wheat can beaffected by frosts and again not produce a full crop.

Soil:

The best soil for growing wheat is loam that is a mixture of clay, sand and humus.If soil is too sandy then water is not retained and plants dry out too quickly, toomuch clay and the reverse applies. The plant has too much moisture and the ground

becomes waterlogged making it difficult for plants to put down roots.

In preparing the soil for planting farmers test the soil to ensure that the rightnutrients are contained and that the soil has neutral acidity. Fertilisers and lime areadded to restore nutrients and balance acidity. The main fertiliser used in Australiais superphosphate that is rich in phosphorous and derived from bird droppings.

The next step is to plough the land to break up the surface, which allows moistureto soak into the ground for the next crop and it buries any weeds as well as the

remains of the previous crop. The land is then ploughed again to break up the soilready for planting of the seeds. New methods have been introduced whereby the

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soil is not heavily ploughed but it is sprayed with a herbicide to kill the weeds andthen the sowing is commenced. This is called minimum tillage sowing.

Sowing:

Large seeding machines are towed behind a tractor and it places the seed andsometimes fertiliser in the ground at the correct depth to enable germination andthen cover the seeds.

The seeding rates can be varied depending on the climate and soil conditions andcan vary from 1.2 bushels per hectare in arid areas to 4.9 bushels per hectare inmore favourable areas. About 81 hectares per day can be planted using thesemachines.

Weeds, Pests and Diseases:

Australia is a relatively disease and pest free country and wheat production is notgreatly effected at this time.

Weeds compete with the crop to use the water and nutrients in the soil and can becontrolled by crop rotation, using clean weed free seed for planting, herbicides for spraying specific weeds, cultivation of the soil and letting sheep and cattle using the

pasture before sowing.

Rust is one major disease that effects wheat in Australia but scientist have hadsuccess in reducing its impact by developing rust free strains of wheat however asthe disease can mutate, this is an ongoing process. The disease is caused by afungus that grows on the wheat plant and produces small rust like spots on theleaves. The fungus draws water and nutrients from the plant thus causing the plantto produce less grain than healthy plants. Another diseases to effect wheat isrhizoctonia which attacks the roots of the plants.

To prevent diseases farmers can spray herbicides and fungicides to reduce thedisease carrying weeds, burn the stubble from the previous crop, deep rip the soil to

prevent root disease and rotate crops as many diseases do not effect all plants.

Insects can also cause major devastation in crops. Grasshoppers (locusts), aphidsand red -legged earth mites either attack the roots or leaves of the crop and can also

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carry diseases. To control pests it is essential that the soil be healthy so the cropwill be strong and the effect of the pests is limited, cultivating the ground as inweed management to destroy the eggs that are present in the soil, spray insecticideswhich is an expensive and damaging to the environmental or can use biological pestcontrols like ladybirds eating aphids.

Harvesting:

As in cultivation and sowing, large machines complete harvesting. Harvesters cutthe wheat and separate the grains from the stalks and husks. Wheat needs to beharvested as soon as possible after maturing so that the grains are not effected byadverse weather like rain and hail, strong winds or fire.

Changes by Cultivation:

From earliest times, cultivation of wheat has been an ongoing process. It is believed

that cross breeding of Triticum and a related grass genus Aegilops eventuated in breeding of Bread wheats by about 6000 BC. Further cross breeding has resulted inwheat as it is known today and it is derived from natural selection of Emmer,Einkorn and Spelt wheats.

These wheats have the following characteristics:

Emmer:A low yielding, tall (approx 2m), it has small grains and originates from a mutation

with no husk.

Einkorn:Is more resistant to cold, heat, drought, fungal disease and bird predation althoughits yield is lower than Emmer and spelt.

Spelt:

A similar wheat to Emmer however it has a hard husk which cannot be removed

and has a poor yield as it is mostly husk.

Wheat Yields:

Wheat yields were only marginally improved until the advent of mechanisation inthe early 1800's, which enable greater areas to be planted and harvested. The realrevolution in wheat yields occurred in the mid 20th century when a concerted effortwas made to produce high yielding varieties.

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This is shown in the following chart which shows the ten year yield average inAustralia from 1939 to 1990 compared with the 2000-2001 and 2001- 2002 wheatyields.

Wheat Yields in Australia x 1000 tonnes

1940-1950 1951-1960 1961-1970 1971-1980 1981-1990 1991-2000 2001 2002

0.86 1.22 1.23 1.30 1.30 1.76 1.82 1.91

Source :- www.awb.com.au - Australian Bureau of Statistics.

There is a marked improvement of yields coming after the work spent introducinghigh yield wheats in the 1970's.

Currently Australia produces the following wheat types

Name UsesPrime Hard Chinese Noodles, Japanese noodles, blended with lower protein flour for baking products

Hard European breads, Middle East flat breads, Chinese steamed productsPremium White Variety of Asian noodles, instant and fresh noodles, Middle Eastern and Chinese steamed

bread

Standard White Multi purpose wheat used for Middle Eastern, Indian and Iranian flat breads, ChineseSteamed breads

Noodle Wheats Blended with hard white for Japanese and Korean noodles

Soft Wheat Confectionery, baked products including biscuits, pastries, cakes, steamed buns and snack foods

Durum Semolina suitable for the production of high quality wet and dry pasta products andcouscous

General Purpose General purpose milling

Feed Manufacturing animal feed high in protein and containing essential amino acids, mineralsand vitamins

Source - awb.com.au

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Bibliography

Information to complete this assignment has been gained from the followingsources:

Wheat, The story of Wheat on Australian Farms - Fiona HamiltonWheat Farms - Ann Thomas

Web Sites:

www. awb.com.au - Australian Wheat Board

http://worldbook.bigchalk.com - World Book Encyclopaedia on line

http://www.ram-direct.co.uk/farming/stockcrop/wheat

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biology of plant production assignment 1 sp 4 2002

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