Yellow Rust: A century after its appearance, challenge of finding effective variety

Date:05-12-2020

Although it is not a new disease, Yellow Rust (Puccinia striiformis f. sp. tritici (PST)) in wheat has been causing significant damage and losses since its first appearance in 1928-1930.

Until recently, the epidemiological occurrence of Yellow Rust in Argentina was always sporadic and limited to regions with lower average temperatures, such as the southeast of the province of Buenos Aires.

However, due to the spread of susceptible varieties, the spontaneous emergence of new virulent breeds of PST and climate change in the last four campaigns, epiphytes have been recorded and quantified in many wheat-growing areas north and south of Buenos Aires, Entre Ríos, Córdoba, and central and southern Santa Fe.

These factors have made the tolerance of various cultivars a fundamental tool in wheat production, as it facilitates management despite increasingly complex issues that reduce yields, such as poor nutrition, competition from weeds and the presence of other diseases.

Currently in the seed market, there are few varieties that show good properties against Yellow Rust, but that there are some. According to tests by RET INASE, Basilio de Bioceres Semillas is one of them.

Last season, this variety obtained the first place in terms of yield in a trial conducted in La Dulce without the use of fungicides, achieving almost 90 qq/ha.

Guayabo and Gingko, the new varieties of Bioceres Semillas, stand out for their good performance against Yellow Rust and for their good overall results, both in trials and during production throughout the Pampas region, including in Miramar, Pla and Manfredi.

In tests carried out in the Regional Aapresid Bragado-Chivilcoy, Guayabo obtained 74 qq/ha, beating other varieties while the new Gingko variety placed above other varieties participating in its cycle in the CREA Mar y Sierras network, reaching 57 qq/ha on average and providing excellent nutritional values and high levels of protein and gluten.

Given the intrinsic characteristics of the disease, it is highly likely that Yellow Rust will reoccur this season. The good news is that varieties are already available to minimize its impact.

The original Spanish version of this report is from infocampo.com.ar.