Effects of pruning severity and growth retardants on the vegetative growth, flower yield and oil content of damask rose (Rosa damascena Mill.).

Abstract: The effects of pruning height (10, 20 or 30 cm) and growth retardants (cycocel [chlormequat] and maleic hydrazide at 2000, 4000 or 8000 ppm) on the performance of R. damascena were studied in Udaipur, Rajasthan, India during 1993/94. The growth retardants were sprayed after sprouting (when 4-5 leaves were fully developed on shoots) and at 15 days thereafter. Plant height, plant spread, and number of shoots per plant decreased with the increase in growth retardant concentration and decrease in pruning height (i.e. increase in pruning intensity). The effect of the interaction between pruning and growth retardant on vegetative parameters was not significant except on plant spread, which was greatest (1.15 m²) with a pruning height of 30 cm and 2000 ppm cycocel. Flower yield per plant and per hectare, and oil content were also significantly affected by pruning and growth retardant. The interaction between pruning and growth retardant was also significant except on oil content. The greatest flower yield per plant