Leonardo Duarte Pimentel

Repetibilidade em características biométricas do fruto de macaúba

Estimates of repeatability coefficient have been used in character study of several species of palms, helping to define the number and appropriate period of assessment of genotypes to increase the efficiency of breeding programs. For macaw palm there are no reports of such studies. In this context it is important to determine the repeatability coefficient of the following biometric characteristics of fruits: fruit weight, fruit volume, equatorial diameter of the fruit, kernel weight, kernel volume, equatorial diameter of de kernel, and thickness of the endocarp, and the determination of the minimum number of ratings for an efficient selection process and evaluation of macaw palm subsamples. The study was conducted at the Department of Plant Science, Federal University of Vicosa, and 145 macaw palm subsamples were analyzed, from collections made in the states of Minas Gerais, Sao Paulo, Mato Grosso do Sul, Para, Maranhao and Pernambuco. There were significant differences for all traits analyzed, and there was agreement on the magnitude of repeatability coefficients of each feature obtained by different methods. However, the repeatability coefficients ranging between eight characteristics, from 0.68 to 0.99, and were observed for feature endocarp thickness and volume of kernel, respectively. The coefficient of determination obtained from 10 repetitions for the eight features and the four methods were superior to 95%. The evaluation of four fruits is sufficient to assess the traits of macaw palm subsamples with 90% accuracy.

Características físicas do maracujá-azedo em função do genótipo e massa do fruto

Physical traits of the fruits of several progenies were evaluated and the correlations among them were studied. The fruits, originated of natural pollination, were picked up at the harvest stage and classified in two weight classes: 1 -180 to 230 g and 2 -80 to 130 g. of each class were sampled two fruits to evaluate the mass of the fruit (g), mass of the skin (g), mass of the seeds (g), mass of the juice (g), longitudinal length and equatorial diameter of the fruit (mm), thickness of the skin (mm), number of seeds, juice weight per seed (g), ratio skin thickness/ fruit ray, ratio longitudinal length/equatorial diameter, juice content (%), skin ratio (%), seed ratio (%) and residues (%). The thickness of the skin varied among the mass classes, indicating that skin evaluation of different fruit sizes can lead to misunderstandings and the evaluation of the progenies.

Cost of production and profitability ofthe passion fruit plant in the agroindustrial market ofthe Zona da Mata of Minas Gerais State, Brazil

Brazil is the largest world producer and consumer of passion fruit, but in the last years, the national industry of juice started to import pulp to assist the crescent demand of juice (concentrated, integral, nectar and tropical juice). Considering the fruit agro-processor cluster from the Zona da Mata Mineira, it is observed that the demand for fruit is not being fully achieved, particularly in the case of passion fruit, which is imported in nature from other states or processed (pulp) from other countries, aiming the manufacture of ready to drink juice. Since it is a culture of fast economical return, the passion fruit plant has become attractive for the producers, but there is still lack of information about the production costs and the profitability in the agro industrial market, avoiding the spread of the culture. With the objective of giving a technical and economical support for the development of the culture in the region, it was estimated the costs of production and the economical indicators were calculated: Net Present Value (NPV), Internal Rate of Return (IRR) and Payback (PB). According to the method used for the analyses it is possible to conclude that the cultivation of the passion fruit plant is a profitable activity and of fast return and it is considered a good alternative for investment in the region.

Influência do substrato na germinação e desenvolvimento inicial de plantas de maracujazeiro amarelo (Passiflora edulis Sims f. flavicarpa Deg)

Na maioria das vezes, a muda de maracujazeiro amarelo e produzida a partir de sementes. Neste sentido, o exito no estabelecimento da cultura depende de varios fatores, entre os quais esta a utilizacao de sementes de boa qualidade e a escolha do melhor substrato. Com este trabalho, objetivou-se avaliar a influencia de quatro substratos na germinacao e desenvolvimento inicial de plantas de maracujazeiro amarelo (Passiflora edulis Sims f. flavicarpa Deg), cultivar IAC 277. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Vicosa, de abril a junho de 2004. Foram testados quatro substratos: Plantmax® ; Plantmax® + Areia (1:1 v/v); Plantmax® + Latossolo Vermelho (1:1 v/v); Plantmax® + Latossolo Vermelho + Areia (1:1:1 v/v). Foi utilizado o delineamento experimental em blocos casualizados, com quatro tratamentos e tres repeticoes, considerando-se como unidade experimental, cada 5 recipientes plasticos. Apos 48 dias da semeadura foram analisados: porcentagem de germinacao; comprimento total, da parte aerea e de raiz das plantas e a massa da materia seca total das plantas. Os dados foram submetidos a analise de variância e ao teste de Tukey (a = 0,05). Pelos resultados obtidos nao foram observadas diferencas significativas entre os substratos em todas as variaveis analisadas. Com isso, conclui-se que os quatros substratos utilizados proporcionaram condicoes adequadas a germinacao e ao desenvolvimento inicial de plantas de maracujazeiro amarelo, cultivar IAC 277.

Seleção de progênies de maracujazeiro-amarelo vigorosas e resistentes à verrugose (Cladosporium cladosporioides)

The scab (Cladosporium cladosporioides) is a harmful disease of the yellow passion fruit vine (Passiflora edulis f. flavicarpa). It attacks young tissues of leaves, branches, flowers and fruits, causing necrosis at the infected site. Three passionfruit cultivars and 39 half-sibling progenies were evaluated for plant vigor and scab incidence at the Department of Phytotechnics of the Federal University of Vicosa, in Brazil, in February 2003. A randomized block design with three replication and four plants per parcel were aplayed. Plant vigor and incidence of scab were evaluated according to a scale varying from one (less vigor or low incidence) to five (higher vigor or higher incidence). The selection was simulated independently for resistance to scab and plant vigor and by means of two selection indexes involving the two characters. The selection index 2, with weight -2: 1 for resistance to scab and plant vigor, respectively, gave the most balanced estimated selection gains, around 10% for each one of the characters, and was adopted in this work. Heritabilities of 44,68% and 56,53% were estimated for resistance to scab and plant vigor, respectively. The progenies 2, 3, 6, 7, 19, 20, 22, 27, 32 and 36 were selected based in the selection index 2.

Seleção precoce de maracujazeiro pelo uso da correlação entre dados de produção mensal e anual

The objective of this work was to determine the sampling seasons of productivity and yield components, in passion fruit, that should allow early selection for superior genotypes. One hundred eleven genotypes of yellow passion fruit, from South and Southeast Brazil, were evaluated during two consecutive years. Variables were assessed monthly for: yield per plant, number of fruits per plant and average fruit weight. The monthly and annual data of these variables were correlated to total yield accumulated in the two years. Among the monthly data, the third month provided the best correlation with the accumulated data. Positive and negative selections were simulated with the third month data and compared with selection based on the two years accumulated data. The data from the third month of the first year were adequate for fruit weight selection, but number of fruits and yield per plant would be better selected with data from the third month of the second year.

Influence of the maturity stage and post-harvest storage in germination and initial development processes of yellow passion fruit

The passion fruit is among the main fruit crops cultivated in Brazil. The propagation is predominantly by seeds. Seeds with good quality should be collected at adequate development stage, which can be established according to the fruit maturity stage. The aim of this work was to verify the influence of the fruit maturity stage and the post-harvest storage in the germination and initial development of the seedlings of yellow passion fruit (Passiflora edulis f. flavicarpa). The work was carried out in the Federal University of Vicosa (MG), Brazil. The seeds used were extracted of fruits in three fruit maturity stages (stage 1 - green beginning to alter its fruit epidermis coloration to yellow; stage 2 - fruit with 5 until 50% yellow epidermis coloration and stage 3 - fruit with more than 50% yellow epidermis coloration), and four post-harvest storage periods (0, 3, 6 and 9 days) at room temperature. After, the seeds were sowed in plastic boxes with fine washed sand. The experiment was designed in completely randomized blocks, in a factorial 3 x 4 (maturity stage x post-harvest storage period), with four replications, where each plot was constituted by 50 seeds. It was concluded that, the yellow passion fruit seeds should be extracted at the fruit maturity stages 2 or 3. For the development process of the yellow passion fruit seedlings it was recommended to store the fruits during 3 to 6 days before the seeds extraction.

Repetibilidade em características do fruto do maracujazeiro

The analysis of successive measurements of a trait, in a group of individuals, is a recommended procedure in the genetic improvement of crops, because it is expected that the superiority or inferiority of an individual in relation to the others remains over the measurements. The veracity of this expectation can be evaluated by the coefficient of repeatability of the traits. The objectives of this work were (1) to determine the coefficient of repeatability of the following traits: mean mass, longitudinal length, equatorial diameter, mean mass of pulp and skin, and skin thickness; and (2) to determine the minimum number of evaluations for an efficient process of genotype selection of passion fruit. Data on twenty half-sib progenies from the passion fruit improvement program were used in the study. Differences were observed among estimates of repeatability coefficients obtained by variance analysis and multivariate methods. Principal components analysis based on the covariance matrix always presented higher estimates, mainly for skin thickness and longitudinal length of fruits. Eighteen measurements were enough to predict the real value of individuals with 90% accuracy in the first year of production, for fruit fresh mass, pulp and peel mass, longitudinal length and equatorial diameter.

Evaluation of chilling requirement in peach through grafted twigs

ABSTRACT - The methodologies used for chilling requirement evaluation have limitations in relation to its applicability. The aim of this work was to evaluate the chilling requirement of six peach varieties (‘Rei da Conserva’, ‘Setembrino’, ‘Reliquia’, ‘Convenio’, ‘Campinas-1’ and ‘Biuti’), using one-year-old twigs grafted in the fall. The work was carried out in the Department of Plant Science, at the Federal University of Vicosa (MG), Brazil. The experiment was designed as completely randomized, with fi ve replications, and one grafted plant per plot. According to the results, the chilling requirements for peachs cv. ‘Rei da Conserva’, ‘Reliquia’, ‘Setembrino’, ‘Campinas-1’, ‘Convenio’ and ‘Biuti’ were around 200, 150, 150, 50, 400 and 150 chilling units, respectively. The grafted twigs methodology was effi cient for evaluation of peach chilling requirement. Index terms : adaptation, chilling requirement, dormancy, Prunus persica. INTRODUCAO O pessegueiro e uma especie frutifera que apresenta ampla capacidade de adaptacao a diferentes condicoes ambientais, sendo cultivado em regioes temperadas e subtropicais (Silveira, 2003). No Bra-sil, as condicoes climaticas das regioes produtoras de pessego sao muito variaveis, principalmente em relacao ao frio hibernal necessario para a adaptacao da cultura. O frio tem dupla funcao sobre o mecanismo da dormencia das fruteiras de clima temperado. Induz a entrada e a saida da dormencia, a fi m de permitir a brotacao e a fl oracao (Putti, 2001). Ha cultivares de pessegueiro com baixa ( 400 – 700 horas), moderada alta (> 700 – 900 horas) ou alta necessidade de frio (> 900 horas) (Mariani, 2006).Porem, a estimativa exata da necessidade de frio de determinada planta para a quebra da dor-mencia e praticamente impossivel em condicoes de campo, uma vez que a radiacao solar, as fl utuacoes diurnas de temperatura e outros fatores nao podem ser controlados (Dennis Jr., 2003). Em particular, nas condicoes climaticas subtropicais, o frio neces-sario para a quebra da dormencia das plantas pode nao ocorrer em qualidade e quantidade sufi cientes, o que proporciona alteracoes no comportamento

Efeito do pH da água de embebição e do trincamento das sementes de maracujazeiro amarelo na germinação e desenvolvimento inicial

O maracujazeiro esta entre as principais fruteiras cultivadas no Pais, sendo semeadura o metodo predominante na producao de mudas. Objetivou-se com este trabalho avaliar o efeito do pH da agua de embebicao e do trincamento das sementes nos processos de germinacao e desenvolvimento inicial do maracujazeiro amarelo, cultivar IAC 277. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Vicosa (MG). Os tratamentos foram constituidos de sementes trincadas e nao trincadas embebidas durante 24 horas em solucao de agua destilada com pHs 3,0; 4,0; 5,0; 6,0 e 7,0. Posteriormente, no interior da casa-de-vegetacao, as sementes foram semeadas em caixas plasticas contendo areia fina lavada. Foi utilizado o delineamento experimental em blocos casualizados, num fatorial 5 x 2 (pH da solucao x trincamento da semente), com quatro repeticoes, considerando como unidade experimental, um lote de 50 sementes. Apos 28 dias da semeadura, foram analisadas: porcentagem de germinacao e sobrevivencia; indice de velocidade de emergencia; comprimento total; altura e comprimento da raiz primaria e, massa da materia seca total das plântulas. Concluiu-se que, os valores de pH das solucoes de embebicao foram favoraveis com os pHs de 3,81 e 6,14, para sementes nao trincadas e trincadas, respectivamente. Os valores de pH das solucoes de embebicao nao influenciaram no desenvolvimento inicial do maracujazeiro amarelo. As sementes nao trincadas apresentaram os melhores resultados, nao sendo aconselhavel o trincamento das mesmas nos processos de germinacao e desenvolvimento inicial do maracujazeiro amarelo.