Growth stages booklet pages 2-5

Authors:

James E. Nelson (Asst. Prof., Montana State University, Bozeman, Montana.)
Kenneth D. Kephart (Asst. Prof., University of Idaho, Moscow, Idaho.)
Armand Bauer (Soil Scientist USDA-ARS, Northern Great Plains Research Lab, Mandan, N.D.)
Jeffrey F. Connor ( Grad. Student, Montana State University Bozeman, Montana.)
Photography. Jayme Schlepp, MSU Photo Services

A Message to Growers

Profitable small grain production requires a thorough knowledge of crop development and growth, and how cultural and environmental factors can influence crop development. Crop and weed response to inputs such as fertilizers, pesticides, plant growth regulators and supplemental irrigation depend on the stage of development rather than on calendar date. Improper application timing may reduce chemical or fertilizer effectiveness, and, in some cases, result in crop injury and yield loss.

Proper application timing offers you an opportunity to achieve maximum wild oat control with post-emergence herbicides. Frequently, producers and fieldmen do not take the time to properly determine the development stage of wild oat before selecting and applying a herbicide.

This publication will help you understand wheat, barley and wild oat development and growth. An easy-to-use staging procedure for cereal grains and wild oat is included. Standard development scales (Zadoks, Feekes, Haun) and label recommendations for pesticide application timing can be applied to this staging method.

Special thanks is extended to American Cyanamid Company for assistance in the production of this publication and to manuscript reviewers for their contributions.

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How to Select Plants

Use this method to stage both cereal grains and wild oats.
Use an "M" or zig-zag pattern to select a crop and wild oat plant from 10 locations in each field (Fig. 1).

Fig. 1 Field Scouting Pattern

Use the Point Method to select each plant. Drop to one knee and immediately place your index finger on the ground (Fig. 2). Carefully remove the plant nearest your finger.

Fig. 2. Grower using Point Method

Refer to Figures 3 through 5 and Table 1 to help correctly identify the plant species. Identification may also be made by examining remnants of the attached seed.

Fig 3. Barley collar area.

Fig 4. Wheat collar area.

Fig 5. Wild Oat collar area.

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Identification characteristics of Wheat, Barley and Wild Oat

Characteristic	Wheat	Barley	Wild Oat
ligule	membranous	membranous	membranous
auricles	short and hairy	long, clasping without hair	absent
blades and collars	usually hairy	without hair	long hair on margins
sheaths	usually hairy	without hair	usually without hair
blade twist	clockwise	clockwise	counter-clockwise

Table 1. Identification characteristics for Wheat, Barley and Wild Oat

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Field Staging form

Identify the development stage of at least 10 plants each of the crop and of Wild Oat and record them on one of the staging forms on Page 25, (see example, Fig. 6). The field development stage is the average stage of these plants.

Record below the staging information for one plant per location in the field.

Get blank forms here

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How to Handle Plants

Locate the first leaf (Fig. 7) (Note 5)

The first leaf:

is the lowest leaf and has a blunt tip
may be dead or missing. Look for leaf and sheath remnants at the crown
sheath encloses all later leaves
arises on the opposite side of the plant as the coleoptilar (if present) and the remnants of the coleoptile

Position the Plant

Hold plant so that the first leaf points to your left and carefully fan-out the leaves and tillers. Follow this procedure for consistent results in staging.

Locate the main shoot or stem

The main shoot or stem is usually the tallest and has the most leaves.

Fig 7 Wheat seedling

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Note 5:
Field-grown spring wheat (Triticum aestivum), barley (Hordeum vulgare) and wild oat (Avena fatua) were photographed in the studio. Wheat is used in dissected and close-up views