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CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Little is known about the agronomic aspects of Mexican Sunflower (Tithonia diversifolia), in spite of its potential for multiple uses. In this study, we evaluated the effects of application rates of biofertilizer and irrigation on yield, growth, and leaf chlorophyll and nutrient content of Mexican Sunflower. In an experiment in the Brazilian semi-arid region, we used a 5 × 2 factorial arrangement, consisting of five application rates of biofertilizer (0, 40, 80, 120, and 160 m3 ha-1), with and without irrigation. The statistical design was randomized blocks with three replications. Irrigated plants of Mexican Sunflower had greater dry and fresh matter yields, greater height, and greater leaf area index and leaf contents of K, Zn, and B. However, the high concentration of bicarbonate in the irrigation water reduced the leaf contents of N, Ca, S, Fe, and Mn. The mean increase in the two cuttings obtained with the use of irrigation was 350% and 314% for fresh and dry matter, respectively. The increase in the biofertilizer application increased the leaf chlorophyll contents of irrigated plants; however, it did not result in production or nutritional gains. In regions with low availability of rainfall, irrigated cultivation of Mexican Sunflower is recommended.

Plants have the ability to undergo morphophysiological changes based on availability of light. The present study evaluated biomass accumulation, leaf morphoanatomy and physiology of Neonotonia wightii andPueraria phaseoloides grown in full sunlight, as well as in 30% and 50% shade. Two assays were performed, one for each species, using a randomized block design with 10 replicates. A higher accumulation of fresh mass in the shoot of the plants was observed for both species under cultivation in 50% shade, while no differences were detected between the full sunlight and 30% shade. N. wightii and P. phaseoloides showed increase in area and reduction in thickness leaf when cultivated in 50% shade. There were no changes in photosynthetic rate, stomatal conductance, water use efficiency and evapotranspiration of P. phaseoloidesplants because growth environment. However, the shade treatments caused alterations in physiological parameters of N. wightii. In both species, structural changes in the mesophyll occurred depending on the availability of light; however, the amount of leaf blade tissue remained unaltered. Despite the influence of light intensity variation on the morphophysiological plasticity ofN. wightiiand P. phaseoloides, no effects on biomass accumulation were observed in response to light. As plantas têm a capacidade de sofrer mudanças morfológicas com base na disponibilidade de luz. O presente estudo avaliou a acumulação de biomassa, morfoanatomia foliar e fisiologia de Neonotonia wightii ePueraria phaseoloides cultivadas a pleno sol, bem como a 30 e 50% de sombra. Dois ensaios foram realizados, um para cada espécie, usando um delineamento de blocos casualizados com 10 repetições. Observou-se maior acúmulo de massa fresca na parte aérea das plantas para ambas as espécies cultivadas em 50% de sombreamento, enquanto não foram detectadas diferenças entre pleno sol e 30% de sombreamento. N. wightii e P. phaseoloides mostraram aumento de área e redução da espessura foliar quando cultivadas a 50% de sombreamento. Não houve alterações na taxa fotossintética, condutância estomática, eficiência no uso da água e evapotranspiração nas plantas de P. phaseoloidesem função do ambiente de cultivo. No entanto, os tratamentos sombreados causaram alterações nos parâmetros fisiológicos de N. wightii. Em ambas as espécies, mudanças estruturais no mesofilo ocorreram dependendo da disponibilidade de luz; no entanto, a quantidade de tecido da lâmina foliar permaneceu inalterada. Apesar da influência da variação de intensidade luminosa sobre a plasticidade morfofisiológica de N. wightii eP. phaseoloides não foram observados efeitos na acumulação de biomassa em resposta à luz.

Cratylia argentea is a multi-purpose shrub with potential as a source of protein for livestock, but is rarely used in production units. This study aimed to monitor the establishment of a stand of this plant in a sandy Ultisol (Red-Yellow Argisol), in an area of 4,000 m2 on a rural property in Cruzeiro do Sul, Acre, Brazil, comparing 2 planting methods: (i) transplanting seedlings (78 in total); and (ii) direct seeding (3,820 seeds in 1,910 pits). The existing pasture was sprayed with glyphosate before planting C. argentea. Subsequently, herbicide and mechanical methods were used to control weeds, while fertilizer was applied and the area was mulched. In the first year after planting, activities performed and inputs were recorded along with costs in order to create a reference model for those intending to cultivate this species in the humid tropics. At 10 months after planting, average height of plants was 162 cm (range 70?240 cm) with no effect of planting method. Ninety-seven per cent of plants established from seedlings survived, while 81% of pits established from direct seeding in the field had surviving plants. The cost of establishing a hectare of C. argentea was US$ 1,654.17, with 85.8% of the cost for labor and only 14.2% for other inputs, although costs of producing seedlings and hand-planting them were not considered. Studies to develop planting systems using less labor seem warranted. Made available in DSpace on 2020-10-14T09:12:44Z (GMT). No. of bitstreams: 1 Establishing-Cratylia.pdf: 894419 bytes, checksum: 4430d48124ce63b836b34654996ed4a6 (MD5) Previous issue date: 2020