Optimization of vanilla (Vanilla planifolia Andrews) growth with auxin and Trichoderma harzianum combination treatment

Abstract: Vanilla is a type of spice plant with high economic value. The availability of healthy vanilla seedlings is now one of the conditions for successful large-scale vanilla cultivation. Conventional cultivation of vanilla generally uses a vegetative method (cuttings), in which the growth of roots and shoots is slow, so it needs to be accelerated. Application of the combination of plant growth regulator and biological inoculant is expected to stimulate root growth and development. This study used a completely randomized design (CRD) with two factors, namely auxin, which consisted of 4 concentration levels, namely: A0 (0 ppm), A1 (50 ppm), A2 (100 ppm), A3 (150 ppm); and T. harzianum which consisted of 4 concentration levels, namely: T0 (0 g), T1 (2 g), T2 (4 g), and T3 (6 g). Data analysis used quantitative methods. The results showed that there was no interaction between T. harzianum and auxin. The addition of T. harzianum could increase the vegetative growth of vanilla cuttings in the parameters of shoot growth time, plant height, number of leaves, fresh weight, and root length while the application of auxin affects the increased in the number of roots of vanilla cuttings.