Vegetative development, fruits yield and optimization of pineapple cv. Pérola with different levels of irrigation

Apesar de ser uma planta com necessidades hídricas relativamente baixas, o abacaxizeiro tem demanda permanente de água, variável ao longo do ciclo e dependente do seu estádio de desenvolvimento. Assim, objetivou-se analisar volumes de irrigação no desenvolvimento vegetativo, no rendimento da fruta e na otimização do abacaxizeiro cv. Pérola. O experimento foi realizado na Universidade Federal de Sergipe, município de São Cristóvão (11°01'S, 37°12'W), no delineamento em blocos ao acaso, com quatro tratamentos (lâminas de água) (100% da evaporação do tanque Classe A (523,7mm ano-1); 75% da evaporação do tanque Classe A (392,8mm ano-1), 50% da evaporação do tanque Classe A (261,8mm ano-1) e 0% da evaporação do tanque Classe A, seis repetições e 12 plantas úteis por parcela. O sistema de irrigação foi por aspersão convencional disposto em linha, com pressão de 20mca e vazão de 1,33m3 h-1. A área foliar (cm2) mínima atingida de 4552,6cm2 foi observada no volume de água de 122,9mm ano-1, enquanto a massa seca das folhas (147,6g) foi constatada com 17mm ano-1. O máximo comprimento da folha D (88,9cm) foi estimado com 532,7 mm ano-1. Já o máximo comprimento do fruto (23cm) foi observado na lâmina de 296,9mm ano-1. A massa do fruto máxima estimado de 1.736g foi constatado na lâmina de 356,4mm ano-1. No contexto, a irrigação contribui de forma positiva no desenvolvimento vegetativo e rendimento da fruta do abacaxizeiro. Ressalta-se remuneração mensal líquida de R 1.161,17ha-1, quando se adota lâmina de irrigação de 356,4mm ano-1. _________________________________________________________________________________________ ABSTRACT: Regardless a relatively low water needs, pineapple fruit has a variable behavior related to water need throughout its biological cycle depending on the development stage. The objective of this work was to analyze irrigation on the vegetative development and fruits yield in pineapple cv. Pérola. The experiment was conducted at the Universidade Federal de Sergipe Experimental Station, at São Cristóvão - SE (11°01'S, 37°12'W), in a randomized block design, with four water level treatments as follow: 100% of Class-A (523.7mm ano-1) evaporation pan; 75% of Class-A (392.8mm ano-1) evaporation pan, 50% of Class-A (261.8mm ano-1) evaporation pan and 0% of Class-A evaporation pan, in six replications and twelve plants per plot. The splinkler watering system of irrigation was installed in a line, with an operating pression of 20 mca and a sprinkler dischrage of 1.33m3h-1. A minimum leaf area of 4552.6cm2 was observed, considering a water level of 122.9mm year-1, while a leaf dry matter was 147.6 g in 17mmyear-1. The maximum leaf length (D) of 88.9cm was estimated considering 532.7mmyear-1. The maximum fruit length of 23cm was observed, considering a water level of 296.9mmyear-1. The maximum estimated fruit weight was 1.736g in a water level of 356.4mm year-1. The irrigation seems to contribute in a positive way to the vegetative development in the pineapple fruit yield. It is important to mention that it could be observed a net profit of R 1,161.17 ha-1, when a water level of 356.4mm ano-1 of irrigation was adopted

Reproductive phenology of Dipteryx odorata (Aubl.) Willd (Fabaceae) in two forest areas in the Central Amazon

Long term phenological studies in tropical forests are scarce. A phenological study of Dipteryx odorata was carried out from 1974 to 2000 in two areas of Amazon Forest: Reserva Florestal Ducke (RFD) and Estação Experimental de Silvicultura Tropical (EEST). The objective was to compare the phenological patterns between the two areas, to verify the regularity of flowering and fruiting over a period of 27 years, and to verify the influence of climatic factors in these events. Five trees were marked in the RFD and five in the EEST; and were observed monthly for the presence of flowers, unripe and ripe fruits. The flowering and unripe fruiting presented an irregular pattern in both areas, and also varied with regard to duration and period of occurrence between years and seasons. Nevertheless, they presented similar frequency of occurrence during the 27 years of observation. On the other hand, the production of ripe fruits presented a different pattern, with three year intervals without ripe fruits in the RFD, and seven year intervals in the EEST. We concluded that the frequency of flowering and unripe fruiting was annual, and the frequency of occurrence of ripe fruiting was supra-annual, with an irregular pattern, and a duration from intermediate to extended. We also observed the occurrence of one to three year intervals between flowering and unripe fruiting episodes, and one to seven year intervals between episodes with ripe fruiting. The influence of climatic factors in the patterns observed was not clear. We suggest the rational use of natural products extracted from Dipteryx odorata, the "cumaru", especially the fruits, and the development of more long term studies, fundamental for understanding the reproductive phenological patterns as well as the resource offering patterns in tropical forests.Estudos fenológicos de longa duração em florestas tropicais são raros. Foi realizado o acompanhamento fenológico de Dipteryx odorata, no período de 1974 à 2000, em duas áreas de floresta amazônicaa Reserva Florestal Ducke (RFD) e Estação Experimental de Silvicultura Tropical (EEST). O objetivo foi observar os padrões fenológicos nas duas áreas, verificar a regularidade da floração e frutificação num período de 27 anos e a influência dos fatores climáticos nestes eventos. Foram marcados cinco indivíduos na RFD e cinco na EEST e observados quanto à produção de flores, frutos imaturos e maduros. A floração e a produção de frutos imaturos apresentaram padrão irregular nas duas áreas observadas, variando quanto a época de ocorrência e a duração entre anos e estações, mas apresentaram freqüência de ocorrência similar nos 27 anos observados. Para a fenofase frutos maduros este padrão foi diferente, com intervalos de até três anos sem ocorrência de frutos maduros, na RFD e de sete anos na EEST. Conclui-se que a freqüência de ocorrência das fenofases de floração e frutos imaturos foi anual e a de frutos maduros supra-anual, todas com padrão irregular e duração de intermediária a prolongada. Ocorreu variação de um a três anos entre episódios de floração e frutos imaturos e de um a sete anos entre episódios de frutos maduros, não ficando evidente, nesta análise, a influência dos fatores climáticos nos padrões observados. Sugere-se o uso racional dos produtos derivados de Dipteryx odorata, o cumaru, especialmente quanto à exploração de seus frutos e o desenvolvimento de mais estudos de longa duração, fundamentais para entender os padrões fenológicos reprodutivos e de oferta de recursos em florestas tropicais

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

Physiological analysis of leaf senescence of two rice cultivars with different yield potential Análise fisiológica da senescência foliar de duas cultivares de arroz com diferentes potenciais de produtividade

The objective of this work was to evaluate the physiological changes that occur in different leaves during the early and late grain-filling stages of two rice genotypes (Oryza sativa subsp. indica , BRS Pelota cultivar, and O. sativa subsp. japonica , BRS Firmeza cultivar), which present differences in grain yield potential. The plants were cultivated in greenhouse. Pigment content, chlorophyll fluorescence, electron transport and oxygen evolution rate were determined in the grain-filling stage, from the first to the forth leaf (top to bottom). Pigment content, photochemical efficiency of photosystem II and electron transport decreased significantly according to the position of leaves in 'BRS Pelota'. The BRS Firmeza cultivar shows higher pigment content and higher activity of the photosynthetic apparatus in comparison to 'BRS Pelota' during the grain-filling stage.<br>O objetivo deste trabalho foi avaliar as mudanças fisiológicas que ocorrem em diferentes folhas durante o início e o final do estádio de enchimento de grãos em dois genótipos de arroz (Oryza sativa subsp. indica cultivar BRS Pelota e O. sativa subsp. japonica cultivar BRS Firmeza) que apresentam diferenças no potencial de produção de grãos. As plantas foram cultivadas em casa de vegetação. Os teores de pigmentos, a fluorescência da clorofila e a taxa de liberação de oxigênio foram determinados no estádio de enchimento de grão da primeira à quarta folha (do topo à base). O teor de pigmentos, a eficiência fotoquímica do fotossistema II e o transporte de elétrons decresceram significativamente de acordo com a posição das folhas na cultivar BRS Pelota. A cultivar BRS Firmeza apresentou maior teor de pigmentos e maior atividade do aparato fotossintético em comparação à 'BRS Pelota' durante o estádio de enchimento de grão