Promoção do crescimento e da produtividade de salsa (Petroselinum crispum) pelo emprego de cepas comerciais de trichoderma spp.

Abstract

The use of fungi belonging to the genus Trichoderma spp. for the biocontol of pathogens is usual, besides it was observed that some from this fungi are used to promote the plant growth. The objective of this work was to evaluate Trichoderma spp. commercial strains in the promoting seedlings growth and in the productivity of parsley plants, the strains evaluated were: Trichoderma harzianum IBLF 006 WP (Ecotrich WP; Ballagro Agro Tecnologia Ltda., Piracaia, SP, Brazil), Trichoderma harzianum ESALQ 1306 (Trichodermil SC, Koppert Biological Systems, Piracicaba, SP, Brazil), Trichoderma asperellum URM 5911 (Quality WG, BioControle Farroupilha Ltda, Patos de Minas, MG, Brazil), Trichoderma harzianum T22 WG (Trianum WG, Koppert Biological Systems, Piracicaba, SP, Brazil) and Trichoderma harzianum SIMBI T5 (StimuControl SC, Simbiose Agrotechnologia Biológica, Cruz Alta, RS, Brazil). In laboratory assay, seeds of parsley cv. „Graúda Portuguesa‟ were treated with 2 mL of Trichoderma suspension (2.5 × 108 ml-1 conidia per 100 g of seeds) submitted to growth test until 28 days after sowing (DAS). For the greenhouse experiment, parsley seedlings were transplanted into 3.0 L pots containing soil, which was previously treated with 5 mL Trichoderma suspension, totaling 1.5 × 108 conidia per pot. In both, a control without Trichoderma application was included, being arranged in a completely randomized design (CRD). The evaluations were: percentage of germination (PG), root length (RL), shoot length (SL), total length (TL = RL + SL), fresh root mass (FRM), fresh shoot mass (FSM), total fresh mass (TFM = FRM + FSM), root dry mass (RDM), shoot dry mass (SDM), total dry mass (BIO = RDM + SDM), root mass ratio (RMR = RDM/BIO), shoot mass ratio (SMR = SDM/BIO), aerial part/root system retio (AP/RS = SDM/RDM) and productivity at 110 DAS. Althougth no diferences was observed among the Trichoderma treatments and the control about yield, Trichoderma spp. strains provided better TFM (18.98 to 22.92 mg), BIO (3.37 to 4.31 mg) and root system superior to the control (14.20 and 2.44 mg, respectively). Under greenhouse and laboratory conditions. T. harzianum ESALQ1306 was the better strain, suggsting this isolate for applied in the seeds when it aims the initial growth promotion.