Trichoderma no desenvolvimento inicial de Luffa cylindrica M. Roem. (Cucurbitaceae)

Abstract

Luffa cylindrica M. Roem., also known as bucha, is an annual herbaceous species, scandent, with a long stem and belongs to the family Cucurbitaceae. Fiber producing specie, with prominence in the agroindustrial market, currently presents itself as an economical alternative for small farmers, being a sustainable and commercially viable culture. There is still a lack of studies concerning aspects of vegetative development and plant-microorganism interaction, even with the increase in its cultivation in the Brazilian territory. Trichoderma genus fungi are natural soil microorganisms, playing an important role in agriculture as bioprotectors. There are many studies about the use of products formulated based on trichoderma for plant disease biocontrol, protecting seeds in the soil, however, research on the action of different doses of this bioproduct on the initial development in plants is rarer. The present study aimed to identify the action of different doses of trichoderma in the initial development of the bucha. Therefore, seeds from two accessions: Faxinal do Soturno / RS and Santa Maria / RS were treated with different doses of bio-product based on trichoderma, sown on germitest paper, incubated in a greenhouse (BOD) at 27 ºC, with a photoperiod of 12 hours. In a second experiment, the substrate (soil/commercial substrate) was treated with the same doses and distributed in trays with ten cells each and the seeds were sown and incubated under the previous conditions and subjected to the following tests: germination, first count, speed index of germination, length of aerial part and root, surface area, diameter and volume of root, fresh and dry seedling mass and evaluation of mitotic index. The treated seeds responded negatively to the action of the doses applied in relation to the control treatment in all analyzed variables, including mitotic index, and substrate treatment with the seeds of the Faxinal do Soturno access showed the increased germination percentage, in the treatments T3 (0.10mL) and T4 (1.00mL), and in root area, diameter and volume. In the Santa Maria access, there was an increase in the variable first count, and an increase in fresh root mass in T4, dry root mass in T4 (1.00mL) and T5 (10.0mL) and in area, diameter and volume of roots, when compared to the control. It is concluded through these results that the bioproduct based on trichoderma, when applied to seeds and in substrate, affects positively or negatively the initial development of L. cylindrica, however, one must consider the action of different extrinsic and intrinsic factors as the substrate, the population variability of the different accesses, the dosages and the application mode of the bioproduct.