Effect of Different Type Light and Growing Medium on the Growth and Flowering of Two Cultivars of Carnation (Dianthus caryophyllus L.)

This study was carried out in the greenhouse of the Horticulture Department Nursery, College of Agriculture Engineering Sciences, Duhok University, Kurdistan region, Iraq, for the period from 1st Aug 2020 to 1st Mar 2021, to study the effect of five supplemental light (control, natural light, Incandescent 14, Incandescent 18, mixed 14, mixed 18) hours daily and three growing medium (river soil, river soil + 30% local compost, river soil + 60% local compost) on some vegetative growth and flowering of two cultivars of carnation plant. The best results (fewest days) for the number of days from planting to bud emergence, visible flower colour, and anthesis were obtained when the plants were exposed to mixed light colours or incandescent lamps for a 14-hour treatment, Also this treatments were significantly superior in the other characteristics like plant height, flower length and flower diameter compared to the control. Medium with 60% local compost significantly increased all the studied characteristics compared with other mediums. The Ormea (Red) cultivar was significantly superior to the Moonlight cultivar in all studies of characteristics and was early in day numbers for bud emergence, visible flower colour, and anthesis. All second interactions between the investigated factors had a significant influence in all studied characteristics. In addition, the triple interaction between the three factors had a significant impact on all characteristics, including the least days or fewest days to flower anthesis of the Ormea cultivar when planted on medium containing 60% local compost under incandescent 14h, which took 101.80 days compared 176.27 days, with an early reach of 74.47 days for the control. The Moonlight (white) cultivar required the fewest days, 128.93 days, for a medium containing 60% compost under mixed 14h, which needed 123.93 days, compared to the control, which required 195.87 days with an early flowering rate of 71.94 days.