Production of chrysanthemum in different substrates with and without growth promoter pretreatment

The production of flowers has increased in Brazil and has gained more economic importance, especially the chrysanthemum (Dendranthema grandiflora), which responds for approximately 80 % of the total internal flower market. The substrate is a basic input for the production of seedlings that results in plants of good quality, especially in vegetative propagated crops. A study was carried out under greenhouse conditions in randomized block design in 4x2 factorial scheme with the objective to test 4 substrates (S1 - commercial substrate TOPSTRATO HORTALIÇAS®; S2 - 50 % of commercial substrate mixed with 50 % of clay loam soil, S3 - 55 % of clay loam soil mixed with 15 % of washed sand, 15 % of cattle manure and 15 % of wood shavings, and S4 - 25 % of clay loam soil mixed with 25 % of washed sand, 25 % of cattle manure and 25 % of wood shavings, all on volume basis) in combination with pretreatment of stakes with STIMULATE®, growth promoter, in order to produce chrysanthemum cultivar Double Sorted seedlings. For analysis of the growth variables, chrysanthemum stakes with 5 leaves were planted individually in poly tubes. The poly tubes were covered with black screen of 50% shade and irrigated four times a day. At the end of experimental period the seedlings were harvested and growth variables were measured. Analysis of variance revealed significant effect (p ≤ 0.05) of the substrates in plant height (PH) and root length (RL). Substrate S2 presented best results, the PH and RL under this treatment being 12.10, 31.45 and 30.24 %, and 2.75, 18.81 and 14.16 % greater than S1, S3 and S4 substrates, respectively. On the other hand, the stakes without immersion in STIMULATE® showed better growth and significant effects (p ≤ 0.05) were observed in case of number of leaves (NF), fresh and dry weights of shoot, root and total.