Ao Deus todo poderoso e criador das nossas vidas, pela presença constante no meu coração, por guiar meus passos neste caminho, tão árduo e pela família maravilhosa que me concedeu. OFEREÇO Aos meus pais, Walter e Juracy, uma dádiva de Deus para minha vida, pela fé e esperança com que acreditaram na realização deste grande sonho, por toda demonstração incondicional de amor e carinho. Aos meus irmãos, Reginaldo, Edcarlos e Kênia Cíntia, mesmo que distantes pelo incentivo e companheirismo em todos os momentos. Aos meus avós, carinhosamente chamados de "Dindinho e Dindinha" grandes motivadores da minha carreira profissional. A minha tia, Edna, pela ajuda nos momentos mais difíceis, nunca mediu esforço para colaborar com minha formação acadêmica. A Karina Batista pelo carinho, compreensão e presença continua nesta fase da vida. DEDICO A uma grande amiga Alline Campos, pelas as palavras de incentivo e motivação.
2 Calcium (Ca) and boron (B) have been reported as the major macro-and micronutrient required for castor bean plant yield. The objective of this study was to determine the Ca:B ratios (in the growth media and plant tissue) for fruit yield and shoot dry weight of the castor bean (Ricinus communis L.), grown in a nutrient solution, and to evaluate Ca and B supply on concentration and total uptake of Ca, potassium (K), magnesium (Mg), and B, as well on the seed oil content. The treatments were arranged in a 3 × 3 factorial fashion, consisting of three rates of Ca (40, 80, and 160 mg L −1 ) and three of B (0.32, 0.96, and 1.60 mg L −1 ). Calcium and B rates increased the shoot and root dry weight and fruit yield at a Ca:B ratio in the nutrient solution of 166 and 100, respectively. Symptoms of B deficiency were observed in plants supplied with 0.32 mg B L −1 , regardless of the Ca concentration in the nutrient solution. Plants which showed visual symptoms of Ca deficiency cultivated with 40 mg Ca L −1 presented concentration of Ca in plant tissue up to 10 g kg −1 . The concentration and total Ca and B uptake increased with the rates of them. Notwithstanding, the shoot Ca accumulation was improved by B rates. In addition, there were no decreases in K and Mg uptake due to Ca rates. Furthermore, addition of 80 mg L −1 of Ca and 1.60 mg L −1 of B in the growth media increased the seed oil content. The Ca:B ratio in the diagnostic leaf associated with the highest plant dry weight (shoot and root) and fruit yield, was 500 (16 to 20 g kg −1 of Ca, and for 30 to 40 mg kg −1 of B).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.