Flowering, Nutritional Status, and Content of Chloroplast Pigments in Leaves of <i>Gladiolus hybridus</i> L. ‘Advances Red’ after Application of <i>Trichoderma</i> spp.

In this study, we attempt to assess the influence of Trichoderma spp. on the flowering and nutritional status of Gladiolus hybridus L. ‘Advances Red’, as well as on the content of chlorophyll a + b and carotenoids in the leaves. During both years of the experiment, there was a treatment in which Trichoderma fungi were not used (control), and in another treatment, plants were treated with these fungi. After five weeks of cultivation, when leaf apexes were visible above the surface of the substrate, each plant was irrigated with a suspension (20 mL) of mix of Trichoderma spp. (T. viride Schumach-Tv14, T. harzianum Rifai-Thr2, T. hamatum/Bonord/Bainier-Th15). The treatment of the plants Trichoderma-spp. improved their uptake of macro- (P, K and Ca) and micronutrients (Zn, Fe and B), and increased the chlorophyll a + b and carotenoids in their leaves. Trichoderma spp. accelerated the flowering of Gladiolus hybridus L. ‘Advances Red’ by 10–14 days. The fungi stimulated the elongation of inflorescence shoots and inflorescences, in which the number of flowers increased, but flower diameter did not change. Trichoderma spp. improved the nutrients uptake, chlorophyll a + b and carotenoids, and flowering; hence, Trichoderma spp. treatment is suggested for enhancing inflorescence and inflorescence shoots in Gladiolus hybridus.