TheCropSite.com- news, features, articles and disease information for the crop industry

News

Sugarcane: Brown Rust Coming Back - Limit the Damage

22 February 2012

US - Brown rust has not been a problem during the last two seasons for Louisiana sugarcane producers due to cold weather during the preceding winter.

However, rust is the disease with the potential to cause the industry the greatest loss, according to Jeff Hoy, Plant Pathology and Crop Physiology.

Rust susceptible varieties are being grown on approximately two thirds of our acreage. A mild winter like the one we are currently experiencing will likely allow rust to survive and re-emerge as a problem. We could have a severe outbreak this spring. So, what can be done to minimise the impact of brown rust during 2012?

According to Delta Farm Press, the best management practices for brown rust are: plant resistant varieties; diversify the varieties under cultivation; avoid excess fertility; remove green tissue from the row during winter; and apply fungicide.

Which of these should be acted upon this spring?

The varieties being grown are already established for the coming season. Clipping, or mechanically removing the green tissue in which the rust pathogen survives the winter, should have been done during January. This leaves fertility practices and fungicide application.

Research and field observation have indicated that fields with high nitrogen and phosphorus levels experience the most severe rust.

Due to high fertiliser costs and research indicating lower nutrient requirements for the current varieties, growers have modified their fertilisation practices. Therefore, excess fertility is usually not a factor.

The following conditions identify the fields that are likely to be hit hard by rust (the fields that need to be monitored closely).

  • Susceptible variety is planted
  • Various factors result in early, vigorous growth: plant cane; light textured soil; high fertility; and protected location
  • Rust infection is evident on older leaves and beginning on younger leaves of plants with most advanced growth. These plants may be along a tree line or ditch bank.
  • Rust infection becomes evident from late March until early June. The earlier the disease begins and longer it lasts, the more yield loss it will cause, and the more economic benefit will result from fungicide application.

TheCropSite News Desk



Our Sponsors