Effect of Time of Growing Season and Time of Day for Flower Harvest on Flower Yield and Essential Oil Quality and Quantity of Four Rosa Cultivars

摘要

The performance of four Rosa cultivars representing different species (R. damascena 'Gulqandi', R. centifolia 'Sahiwal', R. borboniana 'Lahori' and R. hybrida 'Grass an Teplitz') was evaluated with respect to their floral characteristics under Faisalabad, Pakistan agro-climatic conditions. There was a positive and highly significant interaction between temperature and number of flowers for 'Sahiwal'. As temperature increased, so too did the number of flowers, with a maximum number of flowers/plant inMarch, April and May. This was significantly more than other months of the year. 'Sahiwal' formed the most flowers, followed by 'Grass an Teplitz' then 'Gulqandi'. The effect of time of day of flower harvest (05:00 or 17:00 hr) on the quality and quantity of rose oil produced from these four roses was examined to determine the best harvest time for maximum oil yield, ideal oil content and suitable oil composition. Harvest time significantly affected the quantity and quality (i.e. oil profile and composition) of the oil recovered. Early morning was the best time to harvest flowers for maximum quality and yield of essential oil from all four roses. 'Sahiwal' showed the greatest potential for commercial production of rose essential oil by Faisalabad farmers due to an overall high flower yield over an extended flowering period and relatively high yield of high quality essential oil.