Survival of Self-rooted Rose (Rosa hybrida) as affected by Harvest Stage, Cultivar and Storage period of Budwood wood

Abstract

Roses are the leading cut flower produced in Kenya contributing 70% of total cut flower revenue. Roses may be offered as gifts during occasions such as valentines’, Christmas, and Mothers’ Day. They can also be used for decoration of houses and wedding ceremonies. Low percentage survival rates (less than 50%) of self-rooted cuttings of highly demanded cut rose cultivars (‘Milva’ and ‘Shocking Vasila’) adversely affect their production. This results in increased cost of production and shortage of planting materials consequently delaying planting during the peak periods when export demand is high. In an effort to further understand factors affecting percentage survival in these cultivars, the bud wood development stage and cold storage period of cut wood and their relationship to survival of the two Rosa hybrida, cultivars were evaluated. The bud wood was harvested at flower bud initiation, tight flower bud and full bloom stages and then stored for 0, 3 or 7 days at 2 – 4oC. The treatments were arranged in a completely randomised design with three replications. Bud wood harvested at full bloom stage exhibited significantly (p < 0.05 higher percentage survival than bud wood harvested at flower bud initiation stage in ‘Milva’. Percentage survival of bud wood from tight flower bud and full bloom stages were not significantly different from each other in ‘Shocking Vasila’ though survival from full bloom stage was higher. Storage for 7 days yielded significantly higher percentage survival than 0 days storage in ‘Milva’. Non-storage produced significantly lower percentage survival than 3 and 7 days storage in ‘Shocking Vasila’. Results suggest that the cut wood of the two cultivars should be harvested at full bloom stage and stored for 7 days to achieve higher percentage survival. The cultivars differed significantly in their ability to root. ‘Shocking Vasila’ was found to be an easy to root cultivar compared to ‘Milva’ as more than 70% survival was achieved. ‘Milva’ exhibited less than 45% survival hence difficult root cultivar. In order to improve percentage survival in this cultivar, other methods of propagation such as top grafting and tissue culture should be employed. In addition the effects of exogenous auxin and carbohydrate concentrations on percentage survival of this cultivar should be examined.