Food and Agriculture Organization of the United Nations

IRRIGATED WHEAT

Managing your crop


By
Howard M. Rawson
Crop Physiologist
Canberra, Australia
and
Helena Gómez Macpherson
Cereals Officer
Crop and Grassland Service
Plant Production and Protection Division

Table of Contents


FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 2000

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ISBN 92-5-104488-0

© FAO 2000

Table of Contents

Foreword

Acknowledgements

How to use this booklet

Five tenets for managers - the sections of the book
Steps you can take to identify and solve crop problems

Section 1: Reflecting on your farming system

What is your target yield?
Characteristics of a 5t/ha crop as it grows

Section 2: Describing the growth of your crop as stages. During which stages is yield determined?

The Zadoks decimal growth stages
The internal stages that drive development
External & internal stages and when yield is formed
Pictures to help identify all the Zadoks (Z) growth stages

Section 3: Assessing and measuring your crop

Why bother with measurement?
Using your senses to assess problems in your crop
First level of assessment: your eyeball check list
Where, how and what to sample in the field? A numerical assessment
Field sheets. A guide to recording your observations

Section 4: Check lists for problem identification

Check list for planting to the two-leaf stage (Z0.0 to Z1.2)
Check list for three-leaf stage to spike emergence (Z1.3 to Z5.0)
Check list for to early kernel growth (Z5.0 to Z7.02)
Check list for to harvest ripeness (Z6.8 to Z9.2)

Section 5: Problem description and solutions

Environmental factors

Temperature effects
Low temperature
Sunlight effects
Acid or alkaline soils
Saline soils

Management factors

Poor crop stands. Why?
Land preparation
Seed viability
Planting depth and method
Optimum sowing time
Optimum seed rate
The crop canopy: control of tillers and spikes
The crop canopy: green leaves after heading
Lodging
Mineral nutrition
Weeds
Crop Residues
Irrigation timing and moisture stress
Waterlogging

Biotic factors

Above-ground insects
Soil pests
Diseases

Section 6: Explanations of plant development

What advances wheat through its developmental stages?
Thermal time and heat sums
Base and optimum temperature
Photoperiod & vernalization also change rate of development

Section 7: Notes on two tillage systems

Minimum and zero tillage
Raised beds for irrigated wheat

Section 8: Terms used in the booklet

References used in the booklet

Back cover