USAGE OF ACTOSOL (HUMIC ACID) AND SOME GROWTH REGULATORS FOR IMPROVING PLANT QUALITY OF CHAMAEDOREA SEIFRIZII, BURRET

The present experiment was performed during two successive seasons (2017/2018), (2018/2019) at the nursery of Horticulture Research Institute, Agriculture Research Center, Giza, Egypt. It intended to solve the main important problem facing the production of Chamaedorea seifrizii plant under Egyptian conditions of the slow rate of growth especially at the early stage, besides improving plant quality. So, the individual as well as the combined effects of different actosol levels (organic fertilizer) as a main factor and different levels of the mixture of different growth regulators GA₃ (gibberellic acid), BA (benzyladenine) and NAA (naphthalene acetic acid) as a subfactor were investigated. In both seasons (on November, 1^st) transplants of 9-10 cm length and 2-3 leaves were planted in 25 cm plastic pot filled with the mixture of sand and clay (1:1, v/v). Actosol (humic acid) was applied as a soil drench at different levels (0, 1, 2 and 3 ml/l). Whereas the mixture of the different growth regulators it was applied at different levels (0, 50, 150, 250 and 350 ppm) as a foliar spray. All of them were applied at monthly intervals commencing from three months after planting (February, 1^st) till the termination of the experiment (December, 1^st). Thus, the plants were treated by either actosol or the mixture of the different growth regulators 11 times in every season. Results emphasized the beneficial effect of using the highest levels of actosol (2 and 3 ml/l) for improving root length and its fresh and dry weights, comparing with that gained from untreated control plants with significant effect in the two seasons. Meanwhile, the same levels (2 and 3 ml/l) gave rise to the utmost highest values of the different vegetative growth parameters expressed by plant height, No. of leaves/plant, stem diameter and fresh and dry weight of vegetative part, chemical constituents of vegetative parts was also affected by treating plants with actosol. Pigment contents (chlorophyll a, b and carotenoides), total carbohydrates and minerals (N, P and K %) revealed also an increment due to applying the different levels of actosol, with the mastery of applying the highest level (3 ml/l). With respect to the effect of the mixture of the different levels of growth regulators on roots, vegetative growth parameters and chemical constituents of the plant, it is clear the beneficial effect of the mixtures on improving such traits especially with using the highest level (350 ppm) in the two seasons. From the aforementioned results and the interaction, it could be recommended to supply plants with the highest level of actosol (3 ml/l) and that of the mixture of growth regulators (350 ppm) after three months after transplanting and then at monthly interval for 11 times throughout the growth season in order to produce Chamaedorea seifrizii of good quality with solving the problem of the slow rate of growth under Egyptian conditions.