The effect of prunus necrotic ringspot virus on field‐grown roses

Abstract

SUMMARYThe effect of prunus necrotic ringspot virus (PNRSV; cherry serotype) on field‐grown maiden rose bushes cv. Fragrant Cloud was assessed in two trials during 1979 and 1980. PNRSV delayed the onset of flowering, reduced the size and number of blooms and increased the proportion of deformed flowers but had no effect on flower pigmentation or scent. Autumnal leaf‐fall was generally earlier in diseased bushes, which lacked vigour and re‐established less readily after transplanting. Although all healthy plants conformed to the British Standards Institution specifications for maiden bush roses, c. half of diseased plants were sub‐standard because the total diameter of the shoots produced at the bud union was less than 20 mm.The significance of these results is discussed in relation to the commercial production of field‐grown rose bushes in the UK.