Determining the preliminary performance of selected Annonaceae cultivars in subtropical conditions

Plants phenology is extremely important tool for crop management, crop manipulation, and marketing. The objective of this research was to investigate the phenology and fruit quality of the several Annonaceae species under subtropical conditions of Homestead, Florida, USA. The study was carried out in an experimental sugar apple (Annona squamosa L.), orchard with cultivars: 'LeahReese', 'Lessard Thai' and 'Red' and the atemoya ‘Gefner’ (A. cherimola x A. squamosa L). Ten uniformly vigorous and healthy plants of each cultivar were selected. The fruit harvest period was similar for all the cultivars, except for sugar-apple 'LeahReese', which had the shortest harvest period of only 41 days. Multivariate analysis showed that 'Lessard Thai' and 'Red' sugar apple cultivars had smaller sizes and lower chemical quality. Cultivar "LeahResse" had the highest fruits, in addition, a strong correlation with the atemoya hybrid "Gefner". The sugar apples ‘Lessard Thai’ and 'Red' had similar phenology and had a 166-day pruning to harvest cycle. In contrast, 'LeahReese' sugar apple and 'Gefner' atemoya had significantly longer cycles of 182 and 196 days, respectively. The sugar apple 'LeahReese' had the best physical characteristics of the cultivars investigated, while the atemoya 'Gefner' had the best physiochemical characteristics and the longest shelf life

Fruits quality of loquat cultivars in a function of bagging at different development stages

O ensacamento é uma operação de extrema importância no cultivo da nespereira por proporcionar qualidade à colheita de frutas, além de permitir uma minimização na utilização de produtos químicos. Entretanto, ainda existe carência de informações quanto ao momento adequado de realizar a operação, principalmente considerando-se o estádio limite de ensacamento em que se podem obter frutos de qualidade comercial. Em função do exposto, objetivou-se avaliar a qualidade dos frutos ensacados de cultivares de nespereiras em diferentes estádios. Avaliaram-se as cultivares 'Mizuho', 'Mizumo', 'Mizauto', 'Centenária', 'Néctar de Cristal' e a seleção IAC NE-3 a três estádios de ensacamento, ou seja, quando os diâmetros médios deles atingiram 0,5cm, 1,0cm e 1,5cm. Após os frutos atingirem o tamanho de acordo com cada tratamento, realizou-se o ensacamento das panículas, utilizando papel jornal. Quando maduros, os frutos foram colhidos e avaliados quanto ao comprimento, diâmetro e massa do fruto, presença de danos internos e externos. O ensacamento em diferentes estádios de desenvolvimento interferiu na qualidade dos frutos de nespereira. Frutos ensacados com diâmetros entre 0,5 e 1,0cm foram os que apresentaram a melhor qualidade comercial. A seleção IAC NE-3 se destacou entre as nespereiras quanto às dimensões dos frutos.The bagging is an operation of extreme importance in the loquat culture because it provides fruit quality, and allows minimization of chemical products use. However, there is still lack of information, related to the adequate moment to carry through the operation, especially considering the limit of bagging stage, in which there are fruits of marketable quality. Therefore, this study aimed to evaluate the quality of bagged fruits of loquat cultivars in different stadiums of development. The cultivars 'Mizuho', 'Mizumo', 'Mizauto', 'Centennial', 'Crystal Nectar' and selection IAC NE-3 were evaluated in three stages of bagging, that is, when fruits reached an average diameter of 0.5cm, 1.0cm and 1.5cm. After fruits reached the size in accordance to each treatment, the panicles were bagged using newsprint. When mature, the fruits were harvested and evaluated regardless to length, diameter and fruit mass, presence of internal and external damages. The bagging at different developmental stages interfered in the quality of loquat fruit. bagged with diameters between 0.5 and 1.0cm were the ones that had presented the best commercial quality. The IAC NE-3 selection detached e among the loquat fruit due to its dimensions

Emergência e desenvolvimento inicial de plântulas de cupuaçu cultivadas sob diferentes substratos e condições de sombreamento

O cupuaçu pode ser propagado por via sexuada ou assexuada, sendo a via seminífera o processo mais utilizado. Dessa forma, ambientes apropriados para a produção de mudas propiciam melhores condições para o crescimento inicial em campo, colaborando para o aumento da homogeneidade, sanidade e redução da mortalidade de plantas no momento do plantio. Assim, fatores como luz e tipo de substrato são importantes para a germinação de sementes e emergência inicial de plantas. Nesse contexto, objetivou-se com o presente trabalho avaliar o efeito de diferentes substratos, bem como a influência do sombreamento na emergência e no crescimento inicial de plântulas de cupuaçu. O experimento foi conduzido na Embrapa Roraima, utilizando-se delineamento inteiramente casualizado, em esquema fatorial 3 x 7, constituídos de diferentes ambientes (canteiro sem cobertura, canteiro com cobertura tipo sombrite de 50% de luminosidade e canteiro com cobertura plástica transparente de 100 micras), combinados com diferentes substratos (areia, solo, vivatto®, serragem, areia+solo, areia+solo+vivatto® e areia+solo+serragem). Após a semeadura, avaliou-se a porcentagem de emergência e o índice de velocidade de emergência no intervalo de cinco dias, quando, ao final dos 50 dias, avaliou-se o comprimento da parte aérea, o número de folhas, a área foliar, o comprimento do sistema radicular, o diâmetro do caule, a massa seca da parte aérea e do sistema radicular. Observou-se que maior porcentagem de emergência, IVE e desenvolvimento inicial de plântulas de cupuaçuzeiro são obtidos ao se utilizar substrato constituído por areia+solo+serragem. O ambiente com sombreamento de 50% de luminosidade proporciona maior porcentagem de emergência, IVE, diâmetro do colo e massa seca do sistema radicular

Relation between the mineral nutrients and the Vitamin C content in camu-camu plants (Myrciria dubia) cultivated on high soils and flood soils of Ucayali, Peru

Camu-camu is a native plant of the Peruvian Amazon. It is noted for its high concentration of ascorbic acid, however this feature varies widely from one location to another due to genetic and environmental factors. In order to determine the relationship between mineral nutrients and the concentration of ascorbic acid in camu-camu plants, a study was conducted in three camu-camu producing areas in flood-prone soils and soils on dry land conditions in the Ucayali Region. For this purpose, soil samples and camu-camu were collected. The content of following macronutrients was analyzed: nitrogen, phosphorus, potassium, calcium and magnesium; also was determined the concentration of aluminum, pH, organic matter and ascorbic acid. The results show that the camu-camu plantations located in upland soils had lower concentrations of ascorbic acid and lower natural fertility, than soils prone to flooding. Ascorbic acid is negatively related to the concentration of aluminum and positively to the concentration of magnesium and phosphorus in the camu-camu producing areas. It is concluded that the concentration of ascorbic acid in camu-camu plants is best expressed when soils have better chemical attributes and good conditions of natural fertility

Individual selection in a genetic test with 43 advanced progenies of camu-camu Myrciaria dubia Kunth (McVaugh) in floodable plot near Iquitos, Peruvian Amazon

The research summarized and validated the individual selection of camu-camu (Myrciaria dubia (Kunth) McVaugh) plants. 43 progenies, previously selected in genetic tests and fields of producers of flood areas, were evaluated. Each progeny was installed in a row of 10 half-sister plants, with a space of 3x2 m. Using the SELEGEN (Reml / Blup) Model 63 program, four crops were analyzed, and individuals were selected for each of the 16 descriptors evaluated. For fruit yield, the Tipishca-Río Tigre population stood out, occupying 5 of the first 10 places. The individuals TT0725-4 (Tigre-Tipishca) turned out to be a natural recombinant for fruit yield / weight. And individual 64-8 turned out to be triple recombinant (yield / fruit weight / ascorbic acid). The descriptors with the highest genetic control with r ≥ 0.30 were: average fruit weight, brix degrees, plant height, number of basal branches and petiole length. The criteria of similarity of the morphological markers with the fruit yield are proposed as predictive indexes of productivity. The plant height at two years of age was the most important

AVALIAÇÃO DA QUALIDADE DE PÊSSEGOS ‘REGIS’ MINIMAMENTE PROCESSADOS

O objetivo deste trabalho foi avaliar o efeito do ácido cítrico a 1 e 2% na manutenção de qualidade de pêssegos ‘Régis’ minimamente processados, durante 9 dias de armazenamento sob refrigeração (5±1°C e 85-87% UR) e atmosfera modificada passiva. Foram realizadas análises de cor, firmeza, textura, sólidos solúveis, acidez titulável, pH, CO2 e O2. Observaram-se aumentos no valor a e redução nos valores b e L no pêssego minimamente processado, independentemente do tratamento com ácido cítrico, indicando escurecimento do produto principalmente no 9º dia de armazenamento. De maneira geral, os teores de acidez titulável e pH variaram entre os dias de armazenamento e entre as concentrações estudadas, ao contrário do teor de sólidos solúveis que não se alterou. A firmeza, CO2 e O2 sofreram alterações apenas para o fator tempo de armazenamento ao contrário da textura que se mostrou maior no tratamento com 2% de ácido cítrico. Pode-se concluir que nenhuma das concentrações de ácido cítrico testadas foi eficiente na prevenção do escurecimento enzimático dos pêssegos minimamente processados, armazenados a 5±1°C e 85-87% UR em atmosfera modificada passiva. The aim of this work was evaluate the effect of citric acid at 1% and 2% in the maintenance of the quality of minimally processed ‘Régis’ peaches, during 9 days storage under refrigeration (5±1°C, 85-87% RU) and passive modified atmospheres. The following analyses were realized: color, firmness, texture, soluble solids, titratable acidity, pH, CO2 and O2. Increasing in a value and decreasing in b and L values on minimally processed peaches were observed, independent of the citric acid treatment, indicating a browning on the product mainly on the 9th day of storage. Overall, the levels of titratable acidity and pH changed at the storage period and at the concentrations studied, unlike the content of soluble solids that remained unchanged. The texture, CO2 and O2 changed only for the storage period unlike texture that was higher with the treatment of citric acid 2%. It can be concluded that neither tested concentration of citric acid was effective in preventing enzymatic browning of minimally processed peaches stored the 5±1°C and 85-87% RU and passive modified atmosphere

Effect of plant-growth regulators, adjuvants and artificial pollination on the fixation and quality of Annona squamosa L cultivars’ fruit

The aim of the study was to assess the effect of plant regulators (gibberellic acid and naphthalene acetic acid) and adjuvant LI 700® with and without hand pollination on the fruiting and quality of Annona squamosa L. cultivars. The experiment was conducted in the experimental orchard of the Florida Tropical Research and Education Center (TREC/UF) in Homestead, Florida, USA. The experimental design in random blocks comprised 14 treatments, 10 repetitions and 3 flowers per treatment and per tree for ‘Red’ and ‘Lessard Thai’ cultivars. To assess quality, 9 fruit from each treatment were used, with 3 repetitions  and 3 fruit per repetition. High instability was observed in fruit fixation rates between cultivars. The application of growth regulators did not increase fruit fixation in the tested cultivars. The application of naphthalene acetic acid had a deleterious effect on the flowers of the sugar apple cultivars. The most uneven (asymmetrical) fruit was obtained in the treatments with the application of growth regulators. The application of the adjuvant showed toxicity, causing damage to the skin of the fruit. The fruit with the greatest symmetry had the lowest levels of soluble solids and the highest toxicity. The application of growth regulators associated with hand pollination was not efficient, presenting a low percentage of fruit fixation for Annonaceae cultivars. None of the studied treatments produced parthenocarpic fruit (without seeds). The utilization of an adjuvant in the applied concentration caused damage to the fruit peels (darkening) due to toxicity in both cultivars

Biometric characterization, water absorption curve and vigor on araçá-boi seeds

Araçà-boi is a fruit, which awakes great interest for presenting pulp of quality. Their seeds are recalcitrant and present a relatively short period of viability. The water absorption by seeds is a mechanism of growth resuming of the embryo with a subsequent of the tegument breakage by the radical. The seed electric conductivity is a vigor testing is directly related to the membrane permeability. Study of the curve of water absorption by the araçá-boi seeds will contribute to characterize their germination process. In this context, studies concerned with seeds were conducted, which characterized the mass, biometrics, water content, electric conductivity and water imbibition by seeds. It was found that the population of plants established in Manaus-AM produces small, medium and large seeds and which present 70.2, 68.2 and 47.5% of moisture. The greatest water increase takes place in the first hour of absorption, regardless of the size of seeds and water absorption velocity is not influenced by their size. The imbibition curves characterized in the 144-hour period, independent of the size of seeds, show changes of two physiological phases. Both the large and medium seeds present smaller conductivity values, obtaining smaller percentages of germination for possessing increased vigor indices

Intraspecific grafting and anatomical compatibility of Eugenia stipitata Mc Vaugh

The E. stipitata is a native fruit tree from the Amazon, currently in the domestication phase due to its high nutritional and economic potential. In this process, studies aiming at the technical feasibility of propagating materials with desirable agronomic qualities are necessary but still incipient. Thus, the objective of this study was to evaluate different grafting methods forE. stipitata propagation and the compatibility between scion and rootstock using anatomical analysis as a tool. For the experiment, a randomized block design was used in a split-plot scheme over time, with three replications. The plots consisted of three grafting types: cleft grafting, side-veneer grafting, and budding. The subplots were four evaluation times: 30, 60, 90, and 120 days after grafting (DAG). The evaluated variables were the grafting success rate, the number of shoots per graft, shoot length, and shoot diameter. There was a significant interaction between the factors under study. During the experimental period, an increasing grafting success rate and the number of shoots emitted were observed for budding, although with a low success rate. Through cleft grafting, there was a complete loss of shoots at 120 DAG, leading to the subsequent death of all tissues. Budding grafting appears as a promising method for E. stipitata propagation, demonstrating vascular tissue connection feasibility, although this effect did not reflect in the grafting success rate.