GB/T 17980.21-2026Pesticides - Guidelines for field efficacy trials - Part 21: Fungicides against seed-borne diseases of cereals (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document is Part 21 of GB/T 17980, "Guidelines for Field Efficacy Testing of Pesticides". GB/T 17980 has published the following... part.

1.Insecticide control of lepidopteran borers in rice;

2.Insecticide Control of Rice Leaf Roller;

3.Pesticide Control of Rice Leafhoppers;

21.Fungicides for the Control of Seed-borne Diseases in Cereals;

---Part 149: Insecticides for the Control of Red Imported Fire Ants. This document replaces GB/T 17980.21-2000 "Guidelines for Field Efficacy Testing of Pesticides (I) Control of Seed-borne Diseases in Cereals with Fungicides". Compared with GB/T 17980.21-2000, the main technical changes in the "Harmful Effects" standard, apart from structural adjustments and editorial modifications, are as follows:

a) The scope of application has been changed (see Chapter 1, Chapter 1 of the.2000 edition);

b) The requirements for test conditions have been changed (see Chapter 4, Chapter 2 of the.2000 edition);

c) Added provisions regarding experimental treatment and blank controls (see 5.1);

d) The requirements for test and control reagents have been changed (see 5.2,

3.1 of the.2000 edition);

e) Changes were made to cell arrangement, cell size, and duplication requirements (see 5.3,

3.2 of the.2000 edition);

1 Scope

GB/T 17980.21-2026 is the Chinese national standard covering trials of seed treatments against the smuts and bunts carried on cereal seed - diseases invisible until heading, and controlled entirely by what was on the seed before it was drilled. The guideline fixes the trial design and the plots, the timing and rate of application, the assessment of diseased heads at maturity before and after treatment, the calculation of efficacy against the untreated control, and the phytotoxicity to be recorded. It replaces GB/T 17980.21-2000, one of the eight parts of GB/T 17980 revised together in this batch. It was issued on 27 February 2026 and has been in force since 1 September 2026, replacing GB/T 17980.21-2000. The document is under the responsibility of the Ministry of Agriculture and Rural Affairs. This page is published from the official record of the 2026 edition; the clause text of a standard this recent is not yet in circulation, and the figures, limits and tables it contains are those of the document itself, delivered in full with the English translation.

This document describes the methods for field plot trials of fungicides for controlling seed-borne diseases in cereals. This document applies to the fungicide control of wheat netted smut (Tilletiacaries), wheat light smut (Tilletialaevis), and small... Wheat leaf blight (Gerlachianivalis), barley loose smut (Ustilagonuda), barley smut (Ustilagohordei) Barley net blight (Drechslerateres), oat loose smut (Ustilagoavenae), oat smut (Ustilagolevis), etc. For the registration of infectious diseases, field efficacy plot trials and efficacy evaluations should be conducted. Field efficacy trials for similar diseases on other crops should follow the same procedures.

2 Normative references

This document has no normative references.

3 Terms and Definitions

This document does not contain any terms or definitions that need to be defined.

4 Test conditions

4.1 Selection of test subjects, crops and varieties The experimental subjects were smut, stem smut, root rot, snow blight, and net spot disease. The experimental crops are wheat, barley, and oats. Disease-susceptible varieties or locally grown varieties should be selected. Record the variety names.

4.2 Environmental Conditions Field trials should be conducted in disease-prone areas, and the cultivation conditions (soil type, fertilizer, sowing and planting date, and plant spacing) of all experimental plots should be considered. It should be uniform and consistent with local scientific agricultural practices. If irrigation is used, record the method, time, and amount of water used.

5 Experimental Design and Arrangement

5.1 Test Treatment Test reagents, control reagents, and blank controls should be included.