Effects of Foliar Application of Ascorbic Acid, Thiamine and GA3 on Growth, Flowerig and Some Bicchemical Characteristics of Marigold

Graden or bedding plants are suitable for landscape design purposes. Marigold (Tagetes spp.) is currently a popular landscape bedding and garden plant due to its color range and moderate tolerance to drought. Therefore, increasing flower number, flower diameter, and some other parameter related to bedding plants performance such as flowering period are veryimportant. Thus, a CRD -based factorial experiment was conducted to assess the effects of foliar application of some substances on growth, flowering and some biochemical characteristics of marigold. The seeds were sown in pots at the beginning of season. Foliar spray (4 times) was applied at 6-leaf stage and with 10 day intervials using thiamine, ascorbic acid and gibberellic acid (GA3) solely or in combination at 100 and 0 mg-1 with 5 replications. The results indicated the highest fresh and dry weight of shoot and root, the highest stem height, root length, stem diameter and flower diameter (0.87, 1, 1.5 and 1.62 fold, respectively), the highest photosynthetic pigments and reduced sugars were found in the combined treatment of these mentioned chemical, compared to control. Furthermore, parameters such as the average number of lateral shoots, chlorophyll index and flower number were considerably increased compared to control. A synergistic effect was also found when vitamins and GA3 were used simultaneously.