PHYSIOLOGICAL RESPONSE OF GAZANIA PLANTS TO GROWING MEDIA AND ORGANIC COMPOST

This work was carried out during two successive seasons of 2017 and 2018 at the Nursery, Department of Floriculture, Ornamental Horticulture and Landscape Gardening, Faculty of Agriculture, Alexandria University, Egypt to investigate the effect of different growing media (calcareous + sand + peat moss at the rate 70 and 40%) and two types of organic compost (rice straw and sugar beet at 30 and 60%) and their interaction on the growth and flowering of Gazania splendens plants. The experimental design in split-plot arrangement, with four replications, in both seasons. The growing media were laid out in the main plots and sub-plots included the different organic composts. Three pots were used as a plot for each treatment. The means of the individual factors and their interactions were compared by L.S.D. test at 5% level of probability. The obtained results can be summarized as follows;  most vegetative growth characteristics such as: number of tillers (54.74), number of leaves (239.76) and leaves fresh weight (100.29 g) were significantly affected by organic compost at 60% sugar beet with peat moss treatment, flowers characteristics (inflorescences diameter (9.34 cm) and number of inflorescences (14.87), and inflorescences dry weights (0.459 g), responded significantly to the interaction between the different media and organic compost, the highest significant values were obtained by organic compost at 30 and/ or 60% sugar beet and peat moss. Total chlorophyll (56.23 mg/g f.w.), nitrogen (3.42%), phosphorus (0.74%) in the leaves were the highest with 60% sugar beet and 40% peat moss in both seasons. However, potassium (2.85%) in the leaves gave the highest significant values by 60% sugar beet with calcareous soil (40%) for both seasons. It can be recommended that producing high quality of Gazania splendens plants for different decorative purposes in landscaping can be accomplished by growing plants in the mixture of peat moss (40%) with organic compost at rate 60% sugar beet led to improve its characteristics.