Occurrence and effects of stripe rust in wheat spikes in New Zealand

Infection of wheat ( Triticum aestivum L.) spikes with stripe rust ( Puccinia striiformis Westend, f. sp. tritici ) was widespread in crops of susceptible cultivars in the 1983/84 and 1984/85 seasons. In the 1983/84 season in Canterbury, infection was restricted to the cultivars Rongotea, Kopara, and Oroua. In Southland, most crops of ‘Tiritea’ and ‘Takahe’ inspected were infected. Percentage infection of florets was lower in both regions in the 1984/85 season. The lemmas were most often infected, but in severely infected florets the paleas and glumes were also often infected. Grains in infected florets weighed up to 77% less than grains in uninfected florets. The weight loss was related to the severity of infection of individual florets.