WIDESPREAD RSD INCIDENCE IN THE HERBERT DISTRICT

摘要

RSD was identified on 28.4% of 658 farms surveyed in the Herbert district of Queensland during the period 1990-1993. On each farm, four fields of different crop classes were surveyed and 11.3% of fields were found to have RSD infected cane. Disease incidence was 9% in plant crops, 10% in first ratoon, 11% in second ratoon and 15% in older ratoon crops. Of varieties grown in the district, Orpheus (1.5%) and H56-752 (3.9%) had the lowest disease incidence. The major varieties Q115 (14.7%) and Cassius (16.3%) had higher than average disease incidence, whereas Q117 (7.2%), Q119 (7.7%) and Q124 (9.1%) had lower than average disease incidence. From the survey it was calculated that RSD is causing losses to the sugar industry in the Herbert district of over $3M/annum. The use of approved seed in the district declined during the period of the survey. Increased supplies of approved seed have been planted and extension programs are being developed to promote the use of approved seed to control RSD and other diseases.