Productivity and accumulation of nutrients in plants of jambu, under mineral and organic fertilization<br>Produtividade e acúmulo de nutrientes em plantas de jambu, sob adubação orgânica e mineral

The organic production is a system that allows achieving good levels of productivity, while avoiding the risks of chemical contamination of farmers, consumers and the environment. Because jambu plant is widely used as alternative medicine and cosmetics industries, has been increasing interest in its cultivation. The aim of this study was to analyze the biomass, accumulation of nutrient, productivity and determine the pesticide residue in plant jambu when grown under organic and mineral fertilization. The experiment was conducted at the Experimental Farm São Manuel, FCA / UNESP. The experiment was conducted at São Manuel Experimental Farm UNESP. The statistical was arranged in the randomized block design, in a 2 x 6 factorial scheme, two sources of fertilizers (organic and mineral) and six doses of nitrogen, with four replications. The characteristics evaluated were plant height, fresh and dry weight, nutrients of accumulation in shoots and productivity. Mineral fertilizer gave higher biomass, productivity and accumulation of N and K in relation to organic fertilizer used. It is recommended the dose of 90g m-2 of urea as appropriate to obtain these results. However the organic fertilization favored the accumulation of phosphorus in plants jambu in relation the mineral fertilizer, and the dose of 10 kg m-2 of cattle manure recommended to achieve this result in plants jambu. We did not detect the presence of phosphorous and carbamate on leaves of jambu under organic and mineral fertilization. However, we observed the presence of chlorine in the leaves used for the two fertilizations.<p><p>A produção orgânica é um sistema que permite alcançar bons níveis de produtividade, evitando ao mesmo tempo os riscos de contaminação química do agricultor, dos consumidores e do meio ambiente. Pelo fato da planta de jambu ser bastante utilizada como medicamento alternativo e por indústrias de cosméticos, vem aumentando o interesse pelo seu cultivo. Assim, o objetivo desse trabalho foi analisar a biomassa, acúmulo de nutrientes, a produtividade e determinar o resíduo de agrotóxico em plantas de jambu quando cultivado sob adubação orgânica e mineral. O experimento foi conduzido na Fazenda Experimental São Manuel, FCA/UNESP. O delineamento estatístico foi em blocos casualizados, com esquema fatorial (2 x 6), sendo duas fontes de adubação (orgânica e mineral) e seis doses de nitrogênio, com quatro repetições. As características avaliadas foram alturas de plantas, massas frescas e secas de folhas, produtividade e acúmulo de nutrientes. A adubação mineral proporcionou maior biomassa, produtividade e acúmulo de N, P e K em relação à adubação orgânica utilizada. Preconiza-se a dose de 90g m-2 de uréia como adequada para obtenção desses resultados. Com tudo a adubação orgânica favoreceu ao acúmulo de P nas plantas de jambu em relação à adubação mineral, sendo a dose de 10 kg m-2 de esterco de curral recomendada para conseguir esse resultado nas plantas de jambu. Não foi detectada a presença de agrotóxicos fosforados e carbamatos em folhas de plantas jambu sob adubação orgânica e mineral. No entanto, foi observada a presença de clorados nas folhas nas duas adubações utilizada

Biostimulant properties of cyanobacterial hydrolysate related to polyamines

Abstract Developing new and natural sources of plant growth promotors is essential to ensure the safe and sustainable production of vegetables for human consumption. In recent years, the potential of microalgae as plant biostimulants has been investigated. Arthrospira platensis (Spirulina platensis) biomass is a recognized protein source and its enzymatic hydrolysis contains molecules such as polyamines with potential to promote plant growth. Therefore, the aim of the present study was to investigate the biostimulant properties of hydrolyzed biomass of A. platensis. Bioassays were performed to determine auxin-like and cytokinin-like bioactivity of the hydrolysates. In addition, its effect on lettuce seedling growth was investigated and an organic system field trail performed where yield and free polyamine levels in leaves quantified. The hydrolysates had a cytokinin-like effect in the bioassay. Foliar applications promoted the growth of lettuce seedlings with the 4-h reaction hydrolysate (Sph4) being the most effective at promoting growth and increasing the spermine content by 64% in the lettuce leaves. The polyamine concentration was also compared in nonhydrolyzed A. platensis and Sph4. Hydrolysis resulted in a 34% increase in spermine content. It was concluded that Sph4 is a natural plant growth promoter that can be used as a raw material for biostimulants, and spermine could be an active compound and a metabolic indicator of Sph4 bioactivity