Optimum Ratio of Calcium and Boron in the Nutrient Solution or in Castor Bean Shoot for Fruit Yield and Seed Oil Content

Abstract

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).

Isolation and expression analysis of transcripts encoding metallothioneins in oil palm

“…The yield and the quality of palm oil were highly influenced by genes expressed during the final weeks of ripening (Shaarani et al 2010). From the point view of metal ion-binding, the yield and quality of fruit oil are affected by deficiency or excess of macro-and micro-elements (Franco et al 2012). Therefore, it can be assumed that the high homology of the type 2 MT proteins between the two crops, oil palm and maize, may indicate that the MTs have a biosynthesis function as metal chelators, thereby enhancing the oil production process.…”

Influência do boro no teor, acúmulo e eficiência nutricional em porta-enxertos de caramboleira

“…Já em relação ao cobre, a sua eficiência de absorção foi reduzida, após a dose de 1,9 mg dm -3 de B aplicadas ao substrato (Figura 7D). Para Fageria (2002) (Franco et al, 2012). Moraes et al (2002), ao observaram a relação entre a flexibilidade do caule de seringueira (Hevea spp) e a carência de boro, verificaram que a síntese de pectato de cálcio nestas plantas é bloqueada pela carência de boro.…”

Avaliação do estado nutricional, taxa fotossintética e produção de biomassa do sorgo sacarino submetido a combinações de doses de nitrogênio e potássio

“…Os resultados foram submetidos às análises estatísticas utilizando-se o programa estatístico SAS -System for Windows 6.11 (SAS INSTITUTE, 1996) -HAMDAOUI et al, 2003;ZEHIROV;GEORGIEV, 2003;FRANCO et al, 2012;SHAMS et al, 2012…”