Mineral nutrition and yield of sweet potato according to phosphorus doses

Abstract

The sweet potato is a vegetable with potential for expansion of its production area, due to its versatility of use, as it can be used as food, feed and biofuel. However, there is limited information on the mineral nutrition and performance of this vegetable in response to fertilization, especially phosphorus, which is a nutrient with strong interaction with the soil. Given the above, the aim of the present study was to evaluate phosphorus fertilizer levels on growth, mineral nutrition and sweet potato productivity. An experiment carried out from September 3, 2011 until January 3, 2012, in São Luis-MA, aimed to evaluate phosphorus fertilizer levels on growth, mineral nutrition and productivity of sweet potato plants. The experimental design was a completely randomized blocks with four replications. Harvest took place 123 days after seedling transplantation. Phosphorus doses influenced the P level in the soil, plant aerial and root dry matter, total and commercial productivities, and the accumulation of P in the plant aerial part dry matter, tuberous roots and the total plant. The foliar P content was verified to follow a linear adjustment to the doses of P2O5 whereas total and commercial productivities of roots followed a quadratic adjustment. Maximum productivity (1.68 kg m-2) resulted when the P2O5 dose was 191 kg ha-1. The optimal economical dose was 104 kg P2O5 ha-1, that is, 54% of the dose that resulted in the highest commercial productivity.

Rooting of sweet potato seedlings submitted to supplemental calcium and phosphorus nutrition on substrate

“…This indicates that although in the treatment without P the roots reached their maximum growth earlier, the lower P availability in the substrate of this treatment limited root growth to the point of drastically reducing their growth rates. These results, as well as those of other studies, show that depending on the time of seedling permanence in the (Rós et al, 2011; and that P deficiency reduces plant root growth by severely reducing cell division in the root tissues (Sánchez-Calderon et al, 2005) since P acts in the process of energy transfer in the cells (Cruz et al, 2016).…”

“…In the roots, leaves and seedlings, the amounts of DM accumulated increased up to the last evaluation at all P doses. However, in the control treatment, the root and leaf DM in the last two evaluations and the whole seedling' DM in the last evaluation were significantly smaller than those values in the treatments supplied with P ( Figures 4A, C and E), demonstrating that sweet potato responds positively to P fertilization (Cruz et al, 2016). This higher growth of seedlings supplied with P occurred because in these treatments the rates of DM accumulated in the roots and seedlings were higher than those in the treatment without P from 45 days until the end of the permanence of the seedlings in the trays (Figures 4B and F).…”

Doses De Fósforo Na Fertirrigação De Mudas Em Substrato a Base De Fibra De Coco E Influência Na Produção Do Repolho

“…No entanto, o excesso de P também foi prejudicial, pois na maior dose (75 mg L -1 de P) a MFPA das mudas foi de apenas 1,26g. O excesso de adubação fosfatada pode prejudicar as plantas por salinizar o substrato ou por reduzir a disponibilidade de outros nutrientes, dentre os quais micronutrientes catiônicos, principalmente o zinco (CRUZ et al, 2016;SILVA et al, 2016). Tendência semelhante foi obtida para a massa da matéria seca da parte aérea (MSPA), com máximo valor estimado em 0,42g para a dose 40 mg L -1 de P. Os valores obtidos são superiores aos relatados por Godoy e Cardoso (2005), em couve-flor: 0,6 a 1,1g e 0,1 a 0,25g, para as MFPA e MSPA, respectivamente.…”

“…A massa da matéria fresca das raízes (MFR) aumentou linearmente conforme o aumento da dose de fósforo (Figura 1), confirmando o relatado por Cruz et al (2016), ou seja, que este nutriente é importante para o desenvolvimento do sistema radicular. A média da MFR foi de 0,62g, com variação de 0,47g a 0,74g, obtidos na testemunha sem P e na maior dose (75 mg L -1 ), respectivamente.…”

Produtividade De Coentro Verdão Submetido a Doses De Fósforo E Nitrogênio Na Fase Vegetativa

“…Cimó (2018) observou que a testemunha sem P obteve média de 0,47g, enquanto o tratamento de maior dose (75 mg L -1 ), obteve 0,74g de massa fresca da raiz respectivamente. O fornecimento de fósforo em quantidades adequadas é importante para o desenvolvimento do sistema radicular, além de incrementa a produção das culturas (RAIJ 1991;CRUZ et al,2016).…”