Conservação de sementes de portaenxertos de citros em diferentes períodos de armazenamento

Abstract

A key factor for success in citrus production is the use of quality seedlings. Thus, it is necessary to consider factors that interfere with the viability of the seeds used to obtain rootstocks, such as storage time, since it compromises the availability of propagation material at the time of sowing. Based on this, the objective of this work was to evaluate the conservation and physiological quality of seeds of 'Flying Dragon', 'San Diego', 'Índio', 'Cravo Santa Cruz', 'Riverside', 'BRS Sunki Tropical', ' Volkameriano', as well as Poncirus trifoliata during different storage periods, in addition to the incidence of pathogenic fungi and the initial growth of the seedlings. For this, two experiments were carried out. In the first one, the physiological quality of the seeds was evaluated in a factorial 8 x 5 scheme (eight rootstocks and five storage periods: 0, 3, 6, 9 and 12 months), with forty treatments and four replications of fifty seeds. After 45 days, germination percentage, vigor and seed viability were evaluated. It was concluded that, with the exception of Poncirus trifoliata, the seeds of 'Flying Dragon', 'San Diego', 'Índio', 'Cravo Santa Cruz', 'Riverside', 'BRS Sunki Tropical', 'Volkameriano' can be stored for up to six months. In the second test, whose objective was to determine the incidence and carry out the identification of pathogenic fungi in the seeds, the experimental design was completely randomized, with eight replications and 25 seeds per replication. It was verified that after six months of storage, the seeds of all rootstocks presented fungi, such as: Aspergillis spp., Penicillium spp., Fusarium spp., Trichoderma spp., Cephalosporium spp. and Tricodersia spp. In the second chapter, the objective was to evaluate the emergence and initial growth of seedlings of the same cultivars and species used in previous experiments, originating from seeds stored for three months. The experimental design was completely randomized, with eight treatments (eight rootstocks) and four replications with twenty-five seeds. After 120 days, an emergence of 13% was obtained (P. trifoliata); 23% (‘Riverside’); 25%10 ('Volkamerian'), and 24% for the other rootstocks. As for the initial growth of seedlings, there was variation, depending on the cultivar and species studied.