Adubação do feijoeiro (Phaseolus vulgaris L.) em um cambisol do estado de Sergipe

The effects of NPK on the yield of bean was studied by means of a 3³ factorial experiment In an incomplete block design according to Yates confounded W model. The experiment was conducted in the same site for two subsequent years. Rates of nutrient utilized were as follows: nitrogen (0, 20 and 40 kg/ha of N) , phosphorus (0, 50 and 100 kg/ha of P(2)0(5)) and potassium (0, 20 and 40 kg/ha of K(2)0) applied as urea, triple superphosphate and potassium chloride, respectively. All plots received an uniform application of 60 kg/ha of S as calcium sulfate, 4 kg/ha of Zn as zinc sulfate, 4 kg/ /ha of Cu as copper sulfate, 1 kg/ha of B as borax and 0,2 kg/ha of Mo as sodium molibdate. A number of extratreatments was planted with the main field trial to study the effect of sulfur and micronutrients. The same rates indicated above were used. Treatments were as follows: check, complete minus S, complete minus micro and complete (NPK S micro). These treatments were analysed as a randomized block experiment. The results obtained led to the following conclusions: a) yield of common beans was significantly affected by the application of phosphorus in the two years the field experiment was planted; b) no significant effects on the yield of beans were detected for nitrogen, potassium, sulfur and the composite mixture of micronutrients.Os efeitos de NPK na produção do feijoeiro foram estudados através de um experimento fatorial 3³, disposto em blocos incompletos segundo o modelo de confundimento W de Yates. Este experimento foi conduzido dois anos no mesmo local, sendo as seguintes as doses dos nutrientes: nitrogênio (0, 20 e 40 kg/ha de N),fósforo (0, 50 e 100 kg/ha de P(2)0(5)) e potássio (0, 20 e 40 kg/ha de k(2)0) os quais tiveram como fontes uréia, superfosfato triplo e cloreto de potássio, respectivamente. Todas as parcelas receberam uma adubação uniforme com enxofre e micronutrientes, nas seguintes doses e fontes: 60 kg/ha de S como sulfato de cálcio, 4 kg/ha de Zn como sulfato de zinco, 4 kg/ha de cobre como sulfato de cobre, 1 kg/ha de B como borax como borax e 0,2 kg/ha de Mo como molibdato de sódio. Os resultados obtidos permitiram concluir que: a) o fósforo causou aumentos altamente significativos na produção do feijoeiro, nos dois anos de condução do ensaio; b) não foram observados efeitos significativos do nitrogênio, potássio, enxofre e da mistura de micronutrientes na produção do feijoeiro

Chemical fertilization, attack by Aceria guerreronis and productivity of green dwarf coconut

O objetivo deste trabalho foi determinar a influência de níveis de nitrogênio e de potássio aplicados em combinação, via fertirrigação, sobre a produtividade do coqueiro 'Anão-Verde', e a intensidade de ataque do ácaro Aceria guerreronis Keifer (Acari: Eriophyidae). O estudo foi conduzido de fevereiro de 2003 a março de 2004, no Município de Neópolis, SE, em um plantio comercial de coqueiro 'Anão-Verde', com oito anos de idade, que desde o ano 2000 vinha recebendo, via microaspersão, os seguintes tratamentos (gramas de N e K por planta por ano): 135 e 135; 1.890 e 1.890; 810 e 135; 135 e 810; 1.890 e 810; e 810 e 1.890. Foram realizadas quatro avaliações trimestrais, entre abril de 2003 e março de 2004, nos cachos de frutos associados às folhas 14 e 18. A produção de frutos foi influenciada pelos níveis de N e K aplicados ao coqueiral, porém a infestação (8 a 80% de frutos atacados) e a severidade dos danos do ácaro-praga (3 a 47%) não foram afetadas pela adubação química.The objective of this work was to determine the influence of nitrogen and potassium applied through fertigation, on green dwarf coconut productivity, and the intensity of Aceria guerreronis Keifer (Acari: Eriophyidae) attack. The study was carried out in a commercial orchard of eight-year old green dwarf coconut, in the Neópolis County, Sergipe State, Brazil. The orchard received through microsprinkling (fertigation), since 2000, the following treatments (grams per plant per year of N and K): 135 and 135; 1,890 and 1,890; 810 and 135; 135 and 810; 1,890 and 810; and 810 and 1,890. Four evaluations were done every three months between April, 2003 and March, 2004, on fruit bunches associated with the leaves 14 and 18. Fruit production was influenced by N and K level applied on the coconut orchard, but mite infestation (from 8 to 80% of fruits) and the damage severity on fruits (from 3 to 47%) were not significantly affected by the chemical fertilization

Alteration of the physiologic characteristics in banana under fertirrigation conditions

A aplicação de fertilizantes via sistema de irrigação tem se tornado uma prática importante para o suprimento de nutrientes na fruticultura. No entanto, é necessário estudar o efeito dessa aplicação sobre a fisiologia da bananeira a fim de aumentar a eficiência do uso desses insumos. O objetivo deste trabalho foi estudar os efeitos de doses de nitrogênio e potássio, via água de irrigação, sobre as características fisiológicas da bananeira, cultivar ‘Prata-Anã’, nos tabuleiros costeiros do Estado de Sergipe. O experimento foi conduzido no campo, utilizando um fatorial 4x4 com quatro blocos casualizados, na Estação Experimental da Universidade Federal de Sergipe. Foram testados dois fatores: nitrogênio (0; 250; 500 e 750, em kg ha-1 de N, na forma de uréia) e potássio (0; 290; 580 e 870, em kg ha-1 de K2O, na forma de cloreto de potássio). Foram determinadas: a taxa de assimilação de CO2, a transpiração, a condutância estomática, a concentração interna de CO2 e as eficiências no uso da água e da carboxilação. A condutância estomática foi reduzida, principalmente, na fertilização com 700kg ha-1 de N e na ausência de K, afetando as trocas gasosas e, conseqüentemente, o processo fotossintético. Em situações de maior disponibilidade de potássio, as bananeiras necessitam de menores quantidades de nitrogênio para manutenção da eficiência no uso da água, como conseqüência da melhoria no ajuste estomático._________________________________________________________________________________________ ABSTRACT: Fertilizer application through the irrigation system, has become an important way to supply nutrients to fruit trees. However, it is necessary to study its effects on the banana tree physiology, in order to improve fertilizer use efficiency. The objective of this study was to evaluate doses of nitrogen and potassium through irrigation water, on the physiological characteristics of the banana tree, cv. ‘Prata-Anã’, in the coastal tablelands of Sergipe State. The experiment was established in the field, using a 42 factorial with four randomized blocks, at the Sergipe Federal University Experimental Station. Two factors were tested: nitrogen (0; 250; 500 and 750, in kg ha-1 of N, as urea) and potassium (0; 290; 580 and 870, in kg ha-1 of K2O, as potassium chloride). Rate of net CO2 assimilation, transpiration, stomatal conductance, internal leaf CO2 concentration, water use efficiency and carboxylation efficiency were determined. The stomatal conductance was reduced in the fertilization with 700kg ha-1 of N and absence of K, affecting the gas exchanges and, consequently, the photosynthesis. In situations of higher potassium readiness, the banana trees need smaller amounts of nitrogen in order to maintain the efficiency in the water use, as consequence of the best stomatal adjustment

Phosphorous availability as influenced by chemical and mineralogical properties of Sergipe state soils, Brazil

Typescript (photocopy).Sergipe state is located Northeast of Brazil between the parallels 9(DEGREES)31'20" and 11(DEGREES)34'12" south latitude, and between the meridians 36(DEGREES)24'27" and 38(DEGREES)11'20" by longtitude west of Greenwich. Soil samples from ten representative Sergipe state soils were collected to a 20 cm depth and used in this study. Tentatively these soils can be classified as Oxisols, Alfisols, Inceptisols, Entisols and Spodosols. It has been determined that phosphorus is the most limiting nutrient in these soils and that significant response to the nutrient has been observed in corn, beans, cassava, peanuts, cotton and forages. Since the mineralogy of these soils had not been investigated, that was an objective of the present study. Mineralogy of the coarse and fine clay fractions of these samples were determined by XRD, infrared, CEC and total dissolution. Phosphorus status was determined by plant P uptake, fractionation, and parameters of P availability (intensity, capacity and quantity). The mineralogical data revealed that the coarse clay fraction was composed of quartz, feldspars, kaolinite, mica and chlorite. The fine clay fraction was composed of kaolinite and mica. Smectite and chlorite also were detected. Phosphorus availability measured by plant P uptake in the greenhouse was not highly influenced by the chemical and mineralogical properties studied. However, P capacity calculated from sorption isotherms was highly influenced by Fe(,2)O(,3). Phosphorus fractionation data revealed that Al-P and Fe-P were the predominant sources of P. Nevertheless, a considerable amount of P was in occluded, reductant soluble and organic forms. Among the extractants studied 0.05 N H(,2)SO(,4) produced adequate results with the least analytical problems. The mineralogical data should provide more accurate interpretations and extrapolations about chemical and physical properties of these soils. In addition, the P data should contribute to upgrade management decisions on these soils

Phosphorous availability as influenced by chemical and mineralogical properties of Sergipe state soils, Brazil

Typescript (photocopy).Sergipe state is located Northeast of Brazil between the parallels 9(DEGREES)31'20" and 11(DEGREES)34'12" south latitude, and between the meridians 36(DEGREES)24'27" and 38(DEGREES)11'20" by longtitude west of Greenwich. Soil samples from ten representative Sergipe state soils were collected to a 20 cm depth and used in this study. Tentatively these soils can be classified as Oxisols, Alfisols, Inceptisols, Entisols and Spodosols. It has been determined that phosphorus is the most limiting nutrient in these soils and that significant response to the nutrient has been observed in corn, beans, cassava, peanuts, cotton and forages. Since the mineralogy of these soils had not been investigated, that was an objective of the present study. Mineralogy of the coarse and fine clay fractions of these samples were determined by XRD, infrared, CEC and total dissolution. Phosphorus status was determined by plant P uptake, fractionation, and parameters of P availability (intensity, capacity and quantity). The mineralogical data revealed that the coarse clay fraction was composed of quartz, feldspars, kaolinite, mica and chlorite. The fine clay fraction was composed of kaolinite and mica. Smectite and chlorite also were detected. Phosphorus availability measured by plant P uptake in the greenhouse was not highly influenced by the chemical and mineralogical properties studied. However, P capacity calculated from sorption isotherms was highly influenced by Fe(,2)O(,3). Phosphorus fractionation data revealed that Al-P and Fe-P were the predominant sources of P. Nevertheless, a considerable amount of P was in occluded, reductant soluble and organic forms. Among the extractants studied 0.05 N H(,2)SO(,4) produced adequate results with the least analytical problems. The mineralogical data should provide more accurate interpretations and extrapolations about chemical and physical properties of these soils. In addition, the P data should contribute to upgrade management decisions on these soils

Aspectos técnicos e econômicos da bananeira 'Prata-Anã' sob fertirrigação nos tabuleiros costeiros de Sergipe Technical and economical aspects of the banana tree "Prata-Anã" under fertirrigation in the coastal tablelands of Sergipe

Neste trabalho, objetivou-se estudar os efeitos de doses de nitrogênio e potássio via água de irrigação, sobre o tempo de colheita, componentes da produção: número de pencas, número de frutos pencas-1, número de frutos cacho-1 e massa do cacho planta-1, e lucratividade da bananeira Prata-Anã em tabuleiros costeiros do Estado de Sergipe. O experimento foi conduzido no campo, utilizando um arranjo fatorial 4x4 com quatro blocos casualizados, na Estação Experimental da Universidade Federal de Sergipe. Foram testados dois fatores: nitrogênio (0; 350; 700 e 1050, em kg ha-1 de N, na forma de uréia) e potássio (0; 400; 800 e 1200, em kg ha-1 de K2O, na forma de cloreto de potássio). O primeiro ciclo da bananeira 'Prata-Anã' é prolongado em situações de deficiências de N e K. O maior rendimento do cacho (32,56t ha-1) é obtido com a aplicação de 1050kg ha-1 ano-1 de N e 1112kg ha-1 ano-1 de K2O, cujas doses proporcionam uma lucratividade de 27,75 % e uma redução do custo de produção de 40,54%.The objective of the work was to study the effects of doses of N and K applied through irrigation water, on the number of days between planting and harvesting, yield components (number of hands, number of fruits per hands, number of fruits per bunch, bunch weight per plant) and the profitability of the 'Prata-Anã' banana, in the coastal tablelands of Sergipe State. The experiment was carried out in the field at the Sergipe Federal University Experimental Station. A 4² factorial in a randomized block experimental design was used. Treatments were nitrogen (0; 350; 700 e 1050, kg ha-1 of N, as urea) and potassium (0; 400; 800 e 1200, kg ha-1 of K2O, as potassium chloride). Nitrogen and potassium deficiencies increased the number of days between planting and harvesting in the first cycle. Maximum yield of 32.56 t ha-1 was associated with 1050 kg ha-1 year-1 of N and 1112kg ha-1 year -1 of K2O. These doses were able to increase net income by 27.75% and reduced costs by 40.54%