unit consisted of two plants, with six replicates, in a randomized complete block design. (2001).

[ Links ], Silva, N.M., Carvalho, L.H., Kondo, J.I., Bataglia, O.C., Abreu, C.A. No pH natural, teores de matéria orgânica (MO) e de argila foram as variáveis que mais influenciaram a Adsmáx nas camadas superficiais. The samples. This model suc- cessfully described B transport at different water fluxes and pH values when using the adsorption parameters derived from batch equilib- rium experiments. In: Martin-Prevel, P., Gagnard, J., Gautier, P. 1984. This B value is low according to Raij et al.

Entretanto, a fronteira entre biofortificação e toxicidade de Se pode ser estreitada pelo aumento da demanda transpiratória resultante da variação na umidade relativa do ar (UR), contribuindo para que concentrações biofortificantes de Se tornem-se tóxicas. Neste contexto, o enriquecimento ou biofortificação de plantas comestíveis com Se tem sido adotado como estratégia para contornar a deficiência deste elemento no solo. The Langmuir equation with the pH-dependent adsorption coefficient simulated well the B adsorption at equilibrium. Devido a carência de estudos relativos à biofortificação ou toxicidade de Se no Brasil, há a necessidade de mais pesquisas envolvendo este elemento em plantas, sobretudo, considerando-se o papel da UR na absorção de Se pelas plantas.

(2005) for soils with boron levels lower than 0,2 mg dm3־ when the extractor is hot water. SP. As fontes de Se serão avaliadas isoladamente. 25, 371־ 374. The mixture was applied over a 40 cm wide band at a distance of 30 cm from the plant trunk. If one considers 95% of this maximum production the value would be 2,1 kg.ha1־ , quite close to the dosage of 2 kg ha1־ recommended by Teixeira et al. Boron concentrations were significantly higher toward the tips of individual leaflets in both species. (1997), indicating that the soil in the experimental cultures should respond to boron fertilization. Desenvolvimento Sustentável. Campinas. Notwithstanding, mineral nutrition of coconut palm plants has received, poor available information refers essentially to the, mainly of micronutrients, cause reductions in the. Estabelecimento de normas DRIS para. Boron efficiency probably originates from a combined effect of three processes: B uptake, B translocation and retranslocation, and B utilization. 2003. The experimental, An experiment was conducted to standardize the critical boron level in soil and leaf samples of coconut palms grown in a typical Entisol of the Onattukara region of Kerala, India. Some of the most severe disorders caused by boron deficiency include brown-heart of rutabaga (Brassica napobrassica L. Mill), and internal brown-spot of sweet potatoes (Iponoea batatas L. Lam). O coqueiral do sítio São João, com seis anos de idade, com produtividade média de 227 ± 16 frutos planta-1 ano-1, foi amostrado a intervalos de 132 dias, durante dois anos, para estabelecer as normas DRIS, por apresentar as maiores produtividades. [ Links ], Broschat, T.K.

Os parâmetros Adsmáx e KL estimados por regressão não-linear não se correlacionaram com o pH. 1991). McMurtrey (1948) lists the visual symptoms of a number of crops, and in nearly all, the main visual symptoms of boron deficiency are that terminal growth ceases, internodes become shortened, and the plant often acquires a rosetted (bushy) appearance. Benvindo1 and L. Chaves Alencar1, 1Federal University of Piauí, Campus Professora Cinobelina Elvas, Rodovia BR 135, Km 03, 64900-000 - Bom Jesus, Pi, Brazil. 1, 229-276. Mass flow was the predominant mechanism for B transport in soil, supplying 100% of the plant demand in the soils treated with the highest B rates. Boron deficiency in palms. The treatments had consisted of the combination through the experimental matrix of Plan Puebla III, 5 doses of N and 5 doses of K2O both oscillating of 135 the 2565 g plant -1 year -1 derived of the urea and white potassium chloride. Teor foliar de boro em função da aplicação de bórax na axila foliar de coqueiro-anão verde no Norte Fluminense. 33, 1281-1290. Revista Brasileira de Fruticultura. The applied doses of boric acid hadno phytotoxity effect, even when the application was repeated after five months.

O delineamento experimental a ser adotado será o inteiramente casualizado em esquema fatorial 2 x 10 representado pela combinação duas condições de UR (35 e 70%) e dez concentrações de Se (0; 2; 4; 6; 8; 16; 32; 64; 96; 128 µmol L-1) fornecidos na forma de selenato ou selenito. The higher palm tree production was associated to levels of 0.6mg dm-3 of B in the soil and 23.5mg kg-1 in leaves. Os dados obtidos serão submetidos à análise de variância e, em caso de diferenças significativas entre os tratamentos pelo teste F, as médias dos tratamentos de UR serão comparadas entre si dentro de cada concentração de Se. Productivity was expressed by the average number of fruits harvested per plant, per year. Métodos de análise química de plantas. Distribuição de nutrientes e sintomas visuais de deficiência de boro em raízes de coqueiro-anão verde. Boron concentration was determined by the procedure described by Bataglia et al. Trees have a larger body size, longer lifespan and more B reserves than do herbaceous plants, indicating that woody species might undergo long-term or mild B deficiency more commonly and that regulation of B reserves helps trees cope with B deficiency.

Recommendations about boron dosages to be applied to coconut plants are scarcely found in the literature (Teixeira and Silva, 2003; Santos et al., 2003). Hence, adoption of measures such as application of organic manure at 20 kg palm -1 , husk burial in the basin and split application can enhance the nutrient use efficiency.

Maiores quantidades de B foram adsorvidas na amostra superficial do NVef e nos horizontes Bw positivamente carregados dos Latossolos ácricos. This review paper aims at exploring techniques that can be used to amend non-responsive soils and evaluate methods of ameliorating such soils through the proper utilization of nutrients supplied from different organic and inorganic sources. Nutrient Cycling in Agroecosystems. (1995) and Communar and Keren (2006) also point out the importance of factors such as sandy soils, low in organic matter and exposed to heavy rains, which drain much of the boron to deeper layers. Rate-limited boron, transport in soils: the effect of soil texture and. (2008). da., Conceição, H.E.O.

43, 1769-1775.

[ Links ], Pinho, L.G.R., Monnerat, P.H., Pires, A.A., Marciano, C.R., Soares, Y.J.B. The trees growing in a red-yellow Latosol (162 g kg-1 of clay) were artificially irrigated. 32, 2581-2590. em coqueiro-anão-verde. The rain leaches the boron out of sandy soil. 1 Federal University of Piauí, Campus Professora Cinobelina Elvas, Rodovia BR 135, Km 03, 64900-000 - Bom Jesus,Pi, Brazil.