Augusto Miguel Nascimento Lima

DESORDEM FISIOLÓGICA E PRODUTIVIDADE DE MANGUEIRA CV. PALMER ASSOCIADA À NUTRIÇÃO DE BORO

The Sao Francisco Valley is the largest producer of mango under irrigated conditions. In the mango crop, beyond yield, boron is the micronutrient that most affects the fruit quality and this deficiency can cause physiological disorders. Accordingly, an experiment was carried out to evaluate the association of boron with incidence of physiological disorder in mango fruits cv. Palmer and his effect in the fruit yield. The treatments consisted on seven different fertilization managements: T1 = Two fertirrigations with 50 g plant -1 of H3BO3 (fertilizing of the grower); T2 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.2%)]; T3 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.4%)]; T4 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.6%)]; T5 = T1 + two sprays with H3BO3 (0.3%) + three fertirrigations (10 g plant -1 of H3BO3); T6 = T1 + two sprays with H3BO3 (0.3 %) + three fertirrigations (20 g plant -1 of H3BO3); T7 = T1 + two sprays with H3BO3 (0.3%) + three fertirrigations (40 g plant -1 of H3BO3). There is evidence that boron deficiency can cause the emission of fruits affected by physiological disorder and the management of boron fertilization is effective for reducing this problem and also influences mango fruit yield cv. Palmer, detaching that T2 reached an average yield of 35.62 t ha-1, although more studies are needed to recommend a suitable crop management system.The Sao Francisco Valley is the largest producer of mango under irrigated conditions. In the mango crop, beyond yield, boron is the micronutrient that most affects the fruit quality and this deficiency can cause physiological disorders. Accordingly, an experiment was carried out to evaluate the association of boron with incidence of physiological disorder in mango fruits cv. Palmer and his effect in the fruit yield. The treatments consisted on seven different fertilization managements: T1 = Two fertirrigations with 50 g plant -1 of H3BO3 (fertilizing of the grower); T2 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.2%)]; T3 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.4%)]; T4 = T1 + five sprays with H3BO3 [first two (0.3%) and others (0.6%)]; T5 = T1 + two sprays with H3BO3 (0.3%) + three fertirrigations (10 g plant -1 of H3BO3); T6 = T1 + two sprays with H3BO3 (0.3 %) + three fertirrigations (20 g plant -1 of H3BO3); T7 = T1 + two sprays with H3BO3 (0.3%) + three fertirrigations (40 g plant -1 of H3BO3). There is evidence that boron deficiency can cause the emission of fruits affected by physiological disorder and the management of boron fertilization is effective for reducing this problem and also influences mango fruit yield cv. Palmer, detaching that T2 reached an average yield of 35.62 t ha-1, although more studies are needed to recommend a suitable crop management system.

Modeling changes in organic carbon stocks for distinct soils in southeastern brazil after four eucalyptus rotations using the century model

Soil organic matter (SOM) plays an important role in carbon (C) cycle and soil quality. Considering the complexity of factors that control SOM cycling and the long time it usually takes to observe changes in SOM stocks, modeling constitutes a very important tool to understand SOM cycling in forest soils. The following hypotheses were tested: (i) soil organic carbon (SOC) stocks would be higher after several rotations of eucalyptus than in low-productivity pastures; (ii) SOC values simulated by the Century model would describe the data better than the mean of observations. So, the aims of the current study were: (i) to evaluate the SOM dynamics using the Century model to simulate the changes of C stocks for two eucalyptus chronosequences in the Rio Doce Valley, Minas Gerais State, Brazil; and (ii) to compare the C stocks simulated by Century with the C stocks measured in soils of different Orders and regions of the Rio Doce Valley growing eucalyptus. In Belo Oriente (BO), short-rotation eucalyptus plantations had been cultivated for 4.0; 13.0, 22.0, 32.0 and 34.0 years, at a lower elevation and in a warmer climate, while in Virginopolis (VG), these time periods were 8.0, 19.0 and 33.0 years, at a higher elevation and in a milder climate. Soil samples were collected from the 0-20 cm layer to estimate C stocks. Results indicate that the C stocks simulated by the Century model decreased after 37 years of poorly managed pastures in areas previously covered by native forest in the regions of BO and VG. The substitution of poorly managed pastures by eucalyptus in the early 1970´s led to an average increase of C of 0.28 and 0.42 t ha-1 year-1 in BO and VG, respectively. The measured C stocks under eucalyptus in distinct soil Orders and independent regions with variable edapho-climate conditions were not far from the values estimated by the Century model (root mean square error - RMSE = 20.9; model efficiency - EF = 0.29) despite the opposite result obtained with the statistical procedure to test the identity of analytical methods. Only for lower soil C stocks, the model over-estimated the C stock in the 0-20 cm layer. Thus, the Century model is highly promising to detect changes in C stocks in distinct soil orders under eucalyptus, as well as to indicate the impact of harvest residue management on SOM in future rotations.

Boron fertilizing management on fruit production and quality of mango cv. Palmer in semiarid

Adequate fertilizing management is crucial to reach high mango yields that demand a well-defined fertilizer management, including micronutrient such as boron which management is more difficult due to the narrow range between deficiency and toxicity. This way, an experiment was carried out to evaluate the fruit production and quality of mango cv. Palmer as a function of boron fertilizing management in Brazilian semiarid. The experimental design was in randomized blocks with six treatments (strategies for boron fertilizing), as follows: T1 = five sprays with H3BO3 (two first at 0.3% and three at 0.2%); T2 = five sprays with H3BO3 (two first at 0.3% and three at 0.4%); T3 = five sprays with H3BO3 (two first at 0.3% and three at 0.6%); T4 = two sprays with H3BO3 at 0.3% + three fertigations with 10 g of H3BO3 plant -1; T5 = two sprays with H3BO3 at 0.3% + three fertigations with 20 g of H3BO3 plant -1; and T6 = two sprays with H3BO3 at 0.3% + three fertigations with 40 g of H3BO3 plant -1. Boron fertilizing management (foliar spray and fertigation) affects fruit production and quality of mango cv. ‘Palmer’ grown in semiarid. According to the minimum quality criteria required for mango fruit commercialization and the fruit production per plant in semiarid, five sprays with H3BO3 [two first at 0.3% and three at 0.2%] could be recommended.

Production and quality of mango fruits cv. Tommy atkins fertigated with potassium in semi-arid region

1Instituto Federal de Educação, Ciência e Tecnologia do Maranhão. São Raimundo das Mangabeiras-MA. Brasil. E-mail: marcio.carneiro@ifma.edu.br 2Universidade Federal do Vale do São Francisco. Petrolina-PE. Brasil. E-mails: augusto.lima@univasf.edu.br; italo.cavalcante@univasf.edu.br; karla.smsousa@univasf.edu.br; karynebosa@hotmail.com 3Universidade Estadual Paulista “Júlio de Mesquita Filho” Câmpus Araraquara. Araraquara-SP. Brasil. E-mail: fernandac.alencar2010@gmail. com Abstract-Correct management of potassium (K) fertilization is of fundamental importance for mango orchards, and K is one of the most exported and yield-limiting nutrients. Thus, an experiment was carried out to evaluate the production and physical-chemical characteristics of Tommy Atkins mango fruits under fertigation with different doses of potassium chloride and potassium sulfate in the semi-arid region. The experimental design was randomized blocks in split plots, using five K doses (50, 75, 100, 125 and 150% of the recommended dose) in the plots and two sources of K (potassium chloride – KCl and potassium sulfate – K2SO4) in the subplots, with four replicates. The following characteristics were evaluated: transverse and longitudinal diameters, skin thickness, fruit weight, production per plant, pulp percentage, hydrogen potential (pH), soluble solid (SS), ascorbic acid (VIT C), titratable acidity (TA) and SS/TA ratio. The doses and sources of K applied through fertigation caused significant effect on fruit physical-chemical characteristics and production per plant in Tommy Atkins mango, particularly at the dose of 349 g plant-1 of K2SO4, which led to higher production per plant and guaranteed the minimum quality required for fruit physical-chemical characteristics.

Impacto do manejo dos resíduos da colheita, do preparo do solo e da adubação na produtividade de eucalipto

Tem sido cada vez maior a preocupacao das empresas do setor florestal em adotar praticas pautadas na conservacao do solo e da agua. Nesse sentido, este trabalho teve por objetivo avaliar o impacto do manejo dos residuos da colheita, do preparo do solo e do uso de residuos industriais, na fertilidade do solo e produtividade de eucalipto. O experimento foi iniciado apos o corte raso de um plantio comercial de EUCALYPTUS GRANDIS, onde os residuos da colheita foram manejados (retirada de todo o residuo; remocao da casca e dos galhos com diâmetro superior a 3,0 cm; e manutencao de todos os residuos na superficie do solo). Em seguida, realizaram-se o preparo do solo (com subsolador de uma e tres hastes), a aplicacao dos residuos industriais (residuo de celulose e cinzas) na superficie do solo e o plantio de mudas de EUCALYPTUS GRANDIS X E. UROPHYLLA Foi utilizado o delineamento em blocos ao acaso, contendo oito tratamentos e quatro repeticoes. Os tratamentos consistiram da combinacao dos diferentes tipos de manejo dos residuos da colheita, preparo do solo e aplicacao dos residuos industriais. Cada parcela experimental foi composta por cinco linhas com 19 plantas cada. Aos 83 meses apos o plantio, foram medidos o DAP (diâmetro a altura do peito) e a altura das arvores, para calculo do volume de madeira. A fertilizacao e a manutencao dos residuos da colheita florestal elevaram os teores de Ca2+ e Mg2+ trocaveis no solo. A manutencao total dos residuos vegetais na area apos a colheita resultou em aumento de 71,7 m3 ha-1 de madeira, quando comparado a remocao de todos os residuos. Nao houve diferenca entre os modos de preparo do solo com subsolador de uma e tres hastes, quanto ao volume de madeira. Os maiores volumes de madeira foram obtidos dos tratamentos que receberam as maiores quantidades de residuo de celulose e cinzas, ao mesmo tempo em que foi mantida parte do residuo vegetal apos a colheita. A aplicacao do residuo de celulose e cinzas favoreceu a manutencao e, ou, aumento da produtividade do eucalipto.