Impact of Soil Amendments and Irrigation Water on Growth and Flowering of Rosa Plant Grown in Sandy Soil Rosa hybrida

ot experiments were conducted for two successive seasons in Antoniadis Garden, Ornamental Plant Research, Horticulture research Institute. Alexandria, Egypt. Rose plants were grown in sandy soil incorporated with organic compost of municipal solid waste (CMSW)at two levels (5 and 15% w/w) and polyacrylamide at two levels (0.1 and 0.2 % w/w) under irrigation regime at two rates (250ml/plant and 500 ml/plant / 3 times per week) to studytheir effect on the growth, flowering, water consumption,chemical contents of rose plants and improvement of hydro-physic-chemical properties of sandy soil under the study. The obtained results showed that the irrigation water rates did not significantly affect the vegetative parameters, the flowering characteristics except for the flowering time that was significantly reduced. The early flowering was recorded at the lower irrigation rate in the 2nd season. The K, chlorophyll and carbohydrates contents significantly increased in one season only. Anthocyanin content did not significantly increase. Pre-planting addition of CMSW at the higher level (15% w/w) significantly stimulated the vegetative parameters in thetwo seasons. The organic compost at level of 15% w/w of CMSW was more effective in promoting the early flowering (45.9 day) and the heavier flower dry weight (3.26g), prolonged vase life were 7.79 and 7.50 day, maximum number of flowers/plant were 7.82 and 5.08 in the two seasons, respectively. The tallest peduncle was 32.34 and 32.07 cm and the longest duration period was 5.72 and 6.19 in the two seasons, respectively. The N, P and K chemical contents, the total chlorophyll, carbohydrates and anthocyanin were significantly stimulated at the higher level (15% w/w) of CMSW compared to the lower level (5%w/w). Amendment of sandy soil with the hydrophilic synthetic polyacrylamide (PAM) at the level (0.2% w/w) significantly reduced the flowering time, while number of flowers/ plant and flower diameter as well as flower dry weight. The total chlorophyll and carbohydrates contents were significantly accumulated in the leaves as a result of utilizing PAM at level (0.2% w/w). Saturated hydraulic conductivity (Ksat) increase with increasing PAM concentrations. The study recommended to grow rose plants in sandy soil under amended with preplanting organic compost (CMSW) at level (15% w/w) and PAM at level (0.2% w/w) with irrigation rate at 250 ml/ plant/ 3times per week.