Brown rust of wheat

Symptoms

With a large number of pustules, the leaves die, and new pustules can no longer develop on them.

When to look

• Assessment is carried out at the grain filling to milk ripeness stage, as for all types of rust.
• Rust development, above all brown leaf rust on winter wheat, is likely from the stem elongation stage to grain filling.
• To follow the dynamics of development, rust diseases are assessed 3–4 times: before the plants go into winter, at the start of stem elongation, before the start of milk ripeness and 10–12 days after heading, at the start of wax ripeness.
• Winter wheat crops are surveyed on three dates: before the plants go into winter, 10–12 days after heading and at the start of wax ripeness.
• If the disease appears early, the leaves of the lower and middle tiers of susceptible varieties can dry out before the assessment date, so the assessment should be carried out earlier.

How to count

• In fields of up to 100 ha, 20 samples of 10 stems each are taken; on larger areas, 2 additional samples are taken for each 100 ha.
• Infection is rated on the Peterson or Strakhov scale, which shows the conventional and actual percentages of leaf infection.
• Wheat is examined at the places most typical for plant density and plant height. Varieties are divided into groups that differ in the timing of their growth stages.
• Infection is assessed on the top and second leaf tiers (the lower leaf, if present, is also recorded). The leaf and the scale are held at such a distance that the pustules on the leaf and their images on the scale look the same size.
• Leaves that have dried out by more than half are not counted. From the assessment results, the average percentage of plant infection is determined for the first, second and third survey dates.

No rate and no spray timing here: both come from the label and the register.

Yield loss

It causes significant losses to grain farming in Ukraine.

Every fact rests on a quote from its source, and each quote was checked against the page it is printed on.

1. EPPO Global Database · European and Mediterranean Plant Protection Organization
2. Станкевич С. В., Положенець В. М., Немерицька Л. В., Журавська І. А., «Моніторинг хвороб сільськогосподарських культур», навчальний посібник, 301 с. · Інститут біоенергетичних культур і цукрових буряків НААН, Державний біотехнологічний університет; Житомир: Рута, 2022 · p. 146, 149
3. Прогноз фітосанітарного стану агроценозів України та рекомендації щодо захисту рослин у 2025 році · Держпродспоживслужба, НААН, НАН · p. 42
4. Photos: Dávid Horváth, iNaturalist, CC BY 4.0 · Rasbak, Wikimedia Commons, CC BY-SA 3.0 · James Kolmer, Wikimedia Commons, Public domain