Evaluation location: California, United States
Test (513) was conducted at the Spence Farm in Salinas, CA. The field for this test at the Spence Farm is infested with the wild type strain of BNYVV. Trial was planted in April/May in a RCBD of single-row plots 2.74 m in planted length with 0.61 m between plots and 0.71 m row spacing. Stand count (number of plants per plot) was recorded 6-weeks post-planting. Plants were rated for disease as signs and symptoms of infection are seen, typically beginning in September. Evaluation for resistance to rhizomania is based on a composite visual score of foliar color and wilting. Scores for foliar yellowing attributed to rhizomania are evaluated on 0 to 9 scale, where 0 = very dark green with no yellowish plants, and 9 = 100% of the plants showing yellowing typical of rhizomania-susceptible varieties. When present, natural PM infection is scored from 0, clean leaves, to 9, indicating at least 90% or more of the leaf area is covered with visible mildew.
Excel file from Kelly Richardson 2010, 2011, 2012 and 2013 data with multiple worksheets
A general overview of the Rhizomania evaluation work at Salinas, California.