Ana Claudia Costa

Qualidade de tangerinas 'Ponkan' em função da regularidade no raleio químico

Researches suggest that the chemical thinning with appropriate phytoregulators concentrations must be used for more than one year, in order to improve the quality of ‘Ponkan’ tangerines. Thus, the chemical thinning was applied for two years, in this study, in order to evaluate the physicochemical characteristics of ‘Ponkan’ ( Citrus reticulata Blanco) tangerines. The evaluation process was conducted in a twelve-year-old tangerine orchard, grafted on ‘Rangpur’ lime ( Citrus limonia Osbeck), spaced 6.0 m among rows and 3.0 m among plants. The plants were sprayed with four Ethephon concentrations (200 mg L -1 , 400 mg L -1 , 600 mg L -1 and 800 mg L -1 ), after the period of physiological fruit drop, when fruits reached 25-30 mm in transversal diameter, in January 2009 and January 2010. Plants without spraying were used as control. The experimental design was randomized blocks, with four blocks and four plants per plot. There was interaction between the Ethephon concentrations and years of thinning application for percentage of thinning, number of fruits, mass, transversal and longitudinal diameter, soluble solids contents, titritable acidity, ratio and total sugar. There was no effect of Ethephon concentrations for juice yield. The chemical thinning regularity with Ethephon application increased mass, transversal and longitudinal diameter, soluble solids and ratio of ‘Ponkan’ tangerines.

Organic fertilizer and Lithothamnium on the cultivation of red pitaia

The red pitaya is a fruit cactus native from the rainforests of Mexico, Central America and South America that has shown great potential in domestic and foreign markets, due to its hardiness and exotic appearance. The work was carried out to evaluate the influence of organic fertilizers and the application of Lithothamnium (calcified seaweed) on production and fruit quality of red pitaia [ Hylocereus undatus (Haw.) Britton & Rose]. The experimental design was a randomized block with eight treatments: control (no fertilization), cattle manure (CaM), chicken manure (ChM), calcified seaweed (CS), cattle manure + chicken manure, cattle manure + calcified seaweed, chicken manure + calcified seaweed and cattle manure + chicken manure + calcified seaweed. The fertilizers were applied every three months since September 2008, with three blocks, and the experimental unit consisted of four plants. The analyzes done were: yield , number of fruits per plant, fruit mass, pulp yield, transverse diameter, longitudinal diameter, peel thickness, soluble solids (SS), titratable acidity (TA), pH and SS/TA ratio. The highest productivities were obtained in treatments containing CaM + ChM + CS (7.16 t ha-1) and CaM + ChM (6.90 t ha-1) in 2011, and the first treatment also showed higher productivity in 2012 (9.40 t ha-1). Greater number of fruits per plant was obtained when fertilization was carried out with CaM + ChM + CS in the two years evaluated. There were no significant differences among the chemical characteristics of red pitaia fruits with different fertilizations.

Floração e frutificação em diferentes tipos de cladódios de pitaia-vermelha em Lavras -MG

Recentemente, algumas especies de cactaceas tem-se destacado quanto ao potencial como frutiferas, sendo suas frutas utilizadas como alimento para o homem. dentre essas, a pitaia tem despertado grande interesse. O presente trabalho teve como objetivo estudar a floracao e a frutificacao em diferentes tipos de cladodios (tamanho e presenca ou ausencia de frutificacao em safras anteriores) de pitaia-vermelha em Lavras-MG. As observacoes foram realizadas em plantas de pitaia-vermelha [Hylocereus undatus (haw.) Britton & Rose], com quatro anos de idade, tutoradas em mouroes de eucalipto com 1,80 m de altura, no espacamento de 3 x 3 m. Do surgimento do botao floral ate a abertura da flor, decorreram cerca de 21 dias, e da antese ate a colheita do fruto, cerca de 35 dias. Cladodios que ja haviam produzido frutos em anos anteriores e com tamanho entre 40 e 60 cm de comprimento apresentaram maior porcentagem de cladodios com frutos e maior numero de frutos por cladodio.

QUALITY OF PITAIA FRUITS SUBMITTED TO FIELD BAGGING

Nos ultimos anos, com a mudanca no perfil do consumidor, tem aumentado a exigencia por alimentos com niveis reduzidos ou mesmo isentos de agrotoxicos. O ensacamento dos frutos no campo e considerado uma das praticas fitossanitarias mais antigas e eficazes, sendo uma alternativa ao uso do controle quimico. Objetivou-se, no presente trabalho, testar alguns tipos de embalagem no ensacamento dos frutos de pitaia durante seu desenvolvimento na planta, visando a manutencao de sua qualidade. Foram utilizados frutos de plantas de pitaia-vermelha [Hylocereus undatus (Haw.) Britton & Rose] com cinco anos pos-plantio. O delineamento experimental utilizado foi em blocos casualizados, com 5 tratamentos, 4 repeticoes e 10 frutos por parcela. Os tratamentos foram constituidos da testemunha (sem ensacamento), saco de jornal, saco de papel Kraft, saco de papel-manteiga e saco de tecido nao tecido (TNT). As seguintes caracteristicas foram avaliadas: porcentagem de frutos remanescentes ate a colheita, porcentagem de frutos danificados, massa dos frutos, diâmetro longitudinal e transversal, rendimento de polpa, espessura da casca, teor de solidos soluveis (SS), pH, acidez titulavel (AT) e relacao SS/AT. Nao houve diferenca entre os tratamentos para a maioria das caracteristicas analisadas, com excecao do percentual de frutos remanescentes na planta e do percentual de frutos danificados. O ensacamento nao altera as caracteristicas fisicas e quimicas de frutos de pitaia-vermelha. Sacos de TNT e jornal sao mais eficientes no ensacamento de frutos de pitaia devido a maior permanencia nos frutos durante seu desenvolvimento na planta.

Qualidade de pitaia (Hylocereus undatus) submetida à adubação orgânica e armazenada sob refrigeração

Abstract In this work the effect of organic fertilization associated with refrigeration on red pitaya quality was investigated. For 4 years the plants were fertilized every three months according to the following treatments: control (no fertilization) (T1); bovine manure (14 kg / plant) (T2); chicken manure (2 kg / plant) (T3) and chicken manure (2 kg / plant) + bovine manure (14 kg / plant) (T4). The fruits were stored for 21 days at 13 °C and evaluated on days 0, 7, 14 and 21 for loss of fresh mass, colour, firmness, total titratable acidity (TTA), pH, total soluble solids (TSS), TSS / TA, total sugars and reducing and non-reducing sugars. The results showed that during refrigerated storage of the pitaya fruits, the organic fertilization treatments interfered with the quality parameters evaluated, attenuating the loss of fruit quality. It should be highlighted that fertilization with bovine manure associated with chicken manure proved to be more effective than the other organic fertilizers, and resulted in fruits with reduced quality losses during storage.