#Free virus trial

Based on entire genome sequences and the position of virus isolates in phylogenetic trees, occurrence of 11 genotypes of the virus has been reported: BRA, CHN1, CHN3, CUB, FLA1, FLA2, FLA3, HAW, IND, PER, and REU ( Abu Ahmad et al. The causal agent of yellow leaf is a Polerovirus called sugarcane yellow leaf virus (SCYLV). Symptoms of this disease include intense yellowing of the lower side of the sugarcane leaf midrib and necrosis proceeding from the tip toward the base of the leaf. Low virus prevalence observed after three crop seasons suggested that planting virus-free seed cane should limit the impact of SCYLV on sugarcane production in Florida.ДЇirst described in Hawaii in 1989, yellow leaf (previously called yellow leaf syndrome) has been found in most sugarcane-growing areas around the world, including Florida ( Rott et al. However, yield reductions in ratoon crops varied from nonsignificant to 27% depending on cultivar and soil type. No significant negative effect of SCYLV on yield was found in plant cane crop regardless of cultivar and soil type. After three crop seasons, the highest SCYLV prevalence rates were 33 and 7% on organic and mineral soils, respectively. On mineral soil, healthy sugarcane became initially infected in the first ratoon crop. On organic soil, plants of virus-free plots became progressively infected in plant cane and first ratoon crops. Virus prevalence varied from 83 to 100% in plots planted with infected seed cane regardless of cultivar, location, and crop season.

#Free virus trial

Each trial consisted of plots planted with healthy or SCYLV-infected seed cane of two commercial cultivars. Two field trials were set up, one on organic soil and one on mineral soil, to investigate the rate and timing of sugarcane infection by SCYLV under field conditions and the effect of the virus on yield. Sugarcane yellow leaf virus (SCYLV), the causal agent of yellow leaf, is widespread in Florida.