Victor Martins Maia

Pegamento e crescimento inicial de mudas de jabuticabeiras 'Açu' e 'Sabará' submetidas a dois tipos de enxertia

Establishment and growth of grafts of jaboticaba trees ‘Acu’ and ‘Sabara’ sumitted to two types of graft The jabuticabeira (Plinia sp.) Belongs to the Myrtaceae family and is native to Central / South / Southeast Brazil. The aim of this study was to determining the establishment and growth of grafts of jaboticaba trees ‘Sabara’ (P. jaboticaba (Vell)) and ‘Acu’ (P.cauliflora ) submitted to the cleft grafting and whip grafting methods. Were evaluated the initial establishment to 50 days after grafting, the final one at 262 days after grafting, the diameter and lengt of the stem and leaf number appeared to 78, 107 136, 167, 199, 228 e 262 days after grafting. The variety ‘Sabara’ showed higher initial establishment when subjected to the whip grafting method. The jabuticaba ‘Acu’ was greater on the final establishment. Cultivar ‘Acu’ showed larger diameter, longer length of stem and more leaves.

Growth and production of irrigated vitória pineapple grown in semi-arid conditions

This study aimed to evaluate the growth characteristics of irrigated Vitoria pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

Phenotypical correlations between agronomical characters in Prata type bananas (Musa) and its implications on yield estimate

Instituto Federal do Amazonas Campus São Gabriel da Cachoeira, Rodovia BR 307, Km 03, s/no, Estrada do Aeroporto, Cachoeirinha, CEP 69750-000, São Gabriel da Cachoeira, AM. Instituto Federal Baiano Campus Guanambi, Caixa Postal 09, Distrito de Ceraima, CEP 46430-000, Guanambi, BA. Universidade Estadual de Montes Claros, Rua Reinaldo Viana, 2630, Bico da Pedra, CEP 39440-000, Janaúba, MG. Embrapa Mandioca e Fruticultura, Caixa Postal 007, Rua Embrapa, s/n, CEP 44380-000, Cruz das Almas, BA.

PLANTIO IRRIGADO DE BANANEIRAS RESISTENTES À SIGATOKA-NEGRA CONSORCIADO COM CULTURAS ANUAIS

To assess the irrigated cultivation of banana resistant to black Sigatoka, intercropped with annual crops in the northern region of Minas Gerais, a trial was conducted on an experimental farm of the Universidade Estadual de Montes Claros, in Janauba-MG. The experiment was carried out from April 2006 to July 2007, in a 3 x 5 randomized block design with split plots. The plots consisted of three banana varieties (Pacovan Ken, Caipira and Thap Maeo) and subplots of four interim crops (common bean Pearl, okra Dart, watermelon Crimson Sweet and cowpea), with three replications and a control (banana without intercrop). Altogether 756 banana plants were considered, in 45 plots, using 6 central banana plants per plot, representing the main crop. The intercrops were planted in the banana interrows, in those with and those without the irrigation pipeline. The banana and intercrops were planted in the same period. Banana plants were spaced 3.0 m between rows and 2.0 m between plants and irrigated by microsprinklers spaced 6 m apart. Vegetative and reproductive characteristics of the banana varieties were evaluated in the 1st cycle. No significant effect of the crops on the banana varieties was observed, except for the traits number of days from planting to flowering and number of days from planting to harvest of the banana varieties. The cowpea use promoted delay at the crop cycle of three varieties of banana plants Pacovan Ken, Caipira e Thap Maeo.

AVALIAÇÃO DE GENÓTIPOS DE BANANEIRA À Colletotrichum musae EM PÓS-COLHEITA 1

Some tetraploides hybrids present resistance to anthracnose, however the information on the levels of resistance of these genotypes and the behavior in Brazil are reduced. The aim of this study was to evaluate the incidence and severity of injury on the behavior of different banana genotypes resistant to Black Sigatoka for different concentrations of conidia of Colletotrichum musae in different times of evaluation. The fruits of the genotypes, Thap Maeo, Caipira, Pacovan Ken, Ambrosia, PV 42-53, PA 42-44, FHIA 01, FHIA 18 and cultivar Prata Ana, were collected at the stage of physiological maturation. Bunches containing three fruits were atomized with different concentrations: 0, 102, 103, 104, 105 and 106 conidia/mL of C. musae. The fruits were incubated at 25 oC. The incidence and severity of the anthracnose were evaluated 3, 6, 9 and 12 days after the inoculation. A completely randomized experimental design was used, in a factorial scheme 9x6x4 (genotypes, concentrations of spores and evaluation periods) with four replications containing four bunches of three fruits. After twelve days of evaluation all the fruits of all the studied genotypes presented incidence of C. musae when different concentrations of inoculum were used. Concerning the severity of the anthracnose, the cultivar Thap Maeo had the lowest severity (27,5%) of anthracnose while the genotypes Ambrosia, PV 42-53, FHIA 18 and FHIA 01 were the most susceptible to the anthracnose at 64%, 64%, 61,33%, 58% of severity, respectively.

PRODUCTION AND POSTHARVEST QUALITY OF IRRIGATED PASSION FRUIT AFTER N-K FERTILIZATION

Studies with nitrogen and potassium in yellow passion fruit cultivars with high yield potential are scarce in semiarid regions. The aim of this study was to evaluate the influence the N and K doses on productivity and fruit quality of different passion fruit cultivars in irrigated conditions in the northern of Minas Gerais state. The study was installed at experimental farm located in Janaúba-MG. This area was located at 15o 47’ S and 43o 18’ W, 516 m above sea level. The experiment was in completely randomized block with four replications, arranged in 4 x 6 factorial design consisting of four Passion Fruit cultivars (BRS Sol do Cerrado, BRS Ouro Vermelho, BRS Gigante Amarelo, IAC 275) and six N and K doses, which corresponded to 0-0, 50-125, 100-250, 150-375, 200 -500 and 250-625 kg ha-1 yr-1 of N and K2O, respectively. BRS Gigante Amarelo and BRS Sol do Cerrado cultivars showed higher productivity. Total fruit yield and average fruit weight were higher for BRS Sol do Cerrado and IAC 275, BRS Gigante Amarelo and BRS Ouro Vermelho cultivars, respectively. IAC 275 showed the highest pulp yield and along with BRS Sol do Cerrado, showed the higher soluble solids/titratable acidity ratio. BRS Sol do Cerrado, BRS Gigante Amarelo and IAC 275 cultivars showed higher pulp productivity, indicating that they are more promising for passion fruit juice industry.

MACRONUTRIENT CONCENTRATION AND CONTENT IN PASSION FRUIT LEAVES UNDER SAMPLING METHODS AND N-K FERTILIZATION RATES

Nitrogen and potassium fertilization and assessment of adequate nutritional status are essential for increasing fruit production of passion fruit. However, studies related to characterization of the leaf nutrient concentration and content in passion fruit with different production capacities are scarce in the literature in Brazil. The objective of this study was to evaluate macronutrient leaf concentration and content in different parts of the reproductive shoot of yellow passion fruit subjected to different ratios of N and K fertilization. The study was conducted in a randomized block design, with three replications, following a 4 x 6 factorial arrangement consisting of four cultivars of yellow passion fruit (BRS Gigante Amarelo, IAC 275, BRS Ouro Vermelho, and BRS Sol do Cerrado) and six application rates of N-K2O fertilizer (0-0, 50-125, 100-250, 150-375, 200-500, and 250-625 kg ha-1 year-1). Two leaf sampling methods were adopted (leaf located at a position adjacent to the fruit, and leaf located at the end of the reproductive branch) for nutritional assessment. The leaf located at the adjacent position had lower N, P, K, Mg, and S concentration and higher Ca concentration than the concentrations observed in the standard leaf. However, the higher leaf dry matter in adjacent leaves resulted in increased macronutrient concentration/content. The increase in N-K fertilizations inhibited Ca and Mg content in the leaves adjacent to the fruit of the Gigante Amarelo, IAC, and Ouro Vermelho passion fruit cultivars, but did not affect Ca and Mg content in the standard leaf. The passion fruit cultivars showed different leaf nutrient contents after N-K fertilization, indicating variable nutritional demands and the need for specific diagnostic methods for each cultivar.