Quality of brachiaria seeds used in integrated systems

• Autor(a) principal: Avelino, Anne Caroline Dallabrida
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/3506
• topic: Capins tropicais; Contato; Fertilizante; Fungos; Germinação; Fitonematoides; Vigor; CNPQ::CIENCIAS AGRARIAS; Contact; Fertilizer; Fungi; Germination; Phytonematodes; Tropical grasses; Vigor

The crop-livestock integration system (ILP) is a model of sustainable cultivation that allows the recovery of degraded pastures and the intensification of pasture and grain production. However, the presence of pathogens in the production fields has hampered the use of these systems. Based on this, the objective was to carry out a bibliographic review describing the main forages and agricultural crops used in crop-livestock integration systems in tropical regions, the main phytonmatodes associated with these crops and the possible control measures, in addition to identifying the associated fungi the main agricultural and forage crops that cause damage to integrated production systems in Brazilian tropical regions and possible control measures. For this, it was based on a bibliographic review of the Scielo, Scopus and Google Scholar databases, with data from 1999 to 2019. Based on the literature, the cultivation of forages belonging to the genera Brachiaria syn. Urochloa sp. and Panicum syn. Megathyrsus sp., together with soybean, corn, sorghum and millet crops are prevalent in the ILP system of tropical regions. The phytomatomatoides Meloidogyne sp., Pratylenchus brachyurus, Heterodera glycines, Rotylenculus reniformis, Aphelenchoides sp., Ditylenchus sp. and Filenchus sp. can cause greater damage to the main cultures used in ILP. No method of control can eradicate phytonmatodes. The most effective control for the studied phytomatodes is through the integrated management of pests and diseases. The main fungi reported as associated with forage and agricultural crops, and soils from integrated systems in tropical Brazilian regions are Bipolaris sp., Curvularia sp., Exserohilum syn. Helminthosporium sp., Phoma sp., Fusarium sp., Macrophomina sp., Pythium sp., Rhizoctonia sp. and Sclerotium sp. The main methods indicated for fungi control are the use of quality seeds, crop rotation, resistant cultivars and chemical treatment of the seeds. Integrated production systems have been developed to preserve productive resources and maintain the profitability of agribusiness. However, the use of seeds of low physiological and sanitary quality for the implantation of agricultural and forage crops in production fields can favor the dissemination and proliferation of phytopathogens. Thus, the objective was to evaluate the effects of the contact times of brachiaria seeds with the chemical fertilizer on the sanitary quality of brachiaria seeds; to identify the main genera of fungi and phytonmatoids associated with the main tropical forage seeds used in integrated systems, and to distinguish the seeds with high physiological and sanitary quality. Three experiments were carried out in a completely randomized design, in the laboratory, using seeds of brachiaria seeds. The first experiment was carried out in a 5x2 factorial scheme, with four replications. The treatments consisted of the contact times (0, 24, 48, 72 and 96 hours) of the fertilizer 05-25-15 (N-P2O5-K2O) with the seeds of Brachiaria syn. Urochloa ruziziensis cv. Kennedy and B. syn. Urochola brizantha cv. Marandu. After the time of contact of the fertilizer with the brachiaria seeds, the seeds were separated and the analyzes were carried out: water content, germination, health and accelerated aging, with subsequent germination test and sanitary analysis of the seeds. The other two experiments (experiment 1 corresponding to the 2017/18 crop and experiment 2, corresponding to the 2018/19 crop) were performed with four treatments and four replicates each. The treatments consisted of the seeds of Brachiaria syn. Urochloa ruziziensis cv. Kennedy (ruziziensis grasses) and B. syn. Urochola brizantha cultivars Marandu, Xaraés and BRS Piatã (Marandu, Xaraés and Piatã grasses). Cladosporium sp., Fusarium sp., Rhizoctonia sp., Meloidogyne sp., Filenchus sp., Aphelenchus sp., Aphelencoides sp. and Rotylenchulus sp. are the main phytopathogens found in association with the seeds studied in this work. Comparing the seeds studied in this work, the seeds of ruziziensis grasses have better physiological quality and the seeds of xaraés grasses have better sanitary quality.