Potential of Brazilian eugenia myrtaceae - As ornamental and as a fruit crop

Brazilian Myrtaceae comprises several genera of trees and shrubs used for ornamental and fruit production. In addition to the well known Guava, Pitanga and Jaboticaba, other species could be used for fruitculture, due the value and quality of their fruits and adaptation to some climate conditions mainly the subtropical one. Nine species of Eugenia were evaluated at Jaboticabal, located at 48° W and 21° S in São Paulo state in a germplasm bank. The average rain by year is 1431 mm and the temperature 22,2° C at an altitude of 575 m. The species are Eugenia klozschiana Berg. (Pero-do-campo), E. stipitata Mc Vaugh (Araça-boi), E. tomentosa Camb. (Cabeludinha), E. dysentherica DC. (Cagaita), E. brasiliensis Berg. (Grumixama), E.pitanga (Pitanga-anã), E. luchsnathiana Berg. (Pitomba), E. uvalha Camb. (Uvaia) and E. involucrata DC. (Cereja-do-rio-grande). The evaluations comprised tree development, fruit quality and leaf and flower morphological studies. The main results are: the trees of Pera-do-campo and Pitanga-anã are small shrubs of 1 to 2 m height, Araça-boi and Cabeludinha are small trees, 3 to 5 m high, and the other species are tall trees, with 5 to 10 m height. The species adapted well to the subtropical conditions, except for Araça-boi, which is native to the Amazonian region and exhibited a severe fungus disease infection. In relation to fruit quality, all the species had edible fruit, some were sweet and juicy, Cabeludinha, Grumixama, Pitomba, Cereja-do-rio grande and Pitanga-anã, while others had high acidity (Araça-boi, Pera-do-campo, Cagaita and Uvaia and were more suitable for processing. Simple, single leaves were characteristic of all species, but with different sizes and shapes., With the addition of color, smell and other characteristics, leaf size and shape were useful for comparative classification. Flower components and structure are described also.

Estimation of variance components and prediction of breeding values in rubber tree breeding using the REML/BLUP procedure

The present paper deals with estimation of variance components, prediction of breeding values and selection in a population of rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell.-Arg.] from Rio Branco, State of Acre, Brazil. The REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) procedure was applied. For this purpose, 37 rubber tree families were obtained and assessed in a randomized complete block design, with three unbalanced replications. The field trial was carried out at the Experimental Station of UNESP, located in Selvíria, State of Mato Grosso do Sul, Brazil. The quantitative traits evaluated were: girth (G), bark thickness (BT), number of latex vessel rings (NR), and plant height (PH). Given the unbalanced condition of the progeny test, the REML/BLUP procedure was used for estimation. The narrow-sense individual heritability estimates were 0.43 for G, 0.18 for BT, 0.01 for NR, and 0.51 for PH. Two selection strategies were adopted: one short-term (ST - selection intensity of 8.85%) and the other long-term (LT - selection intensity of 26.56%). For G, the estimated genetic gains in relation to the population average were 26.80% and 17.94%, respectively, according to the ST and LT strategies. The effective population sizes were 22.35 and 46.03, respectively. The LT and ST strategies maintained 45.80% and 28.24%, respectively, of the original genetic diversity represented in the progeny test. So, it can be inferred that this population has potential for both breeding and ex situ genetic conservation as a supplier of genetic material for advanced rubber tree breeding programs. Copyright by the Brazilian Society of Genetics.

Visual and acoustic signaling in three species of Brazilian nocturnal tree frogs (anura, hylidae)

Visual communication seems to be widespread among nocturnal anurans, however, reports of these behaviors in many Neotropical species are lacking. Therefore, we gathered information collected during several sporadic field expeditions in central and southern Brazil with three nocturnal tree frogs: Aplastodiscus perviridis, Hypsiboas albopunctatus and H. bischoffi. These species displayed various aggressive behaviors, both visual and acoustic, towards other males. For A. perviridis we described arm lifting and leg kicking; for H. albopunctatus we described the advertisement and territorial calls, visual signalizations, including a previously unreported behavior (short leg kicking), and male-male combat; and for H. bischoffi we described the advertisement and fighting calls, toes and fingers trembling, leg lifting, and leg kicking. We speculate about the evolution of some behaviors and concluded that the use of visual signals among Neotropical anurans may be much more common than suggested by the current knowledge. © 2007 Departamento de Ciências Biológicas.

Leaf spray fertilization of boron and zinc on productivity and fruit quality of Japanese pear tree

The cultivation of fruit plants from temperate climate in tropical or subtropical regions can be a good income alternative for the producer. However, due to the little existent information about cultivation of those fruit plants, the producers use imported techniques of other producing areas, or even an association of practices used for other fruit plants, pointing out the leaf spray fertilization of micronutrients without appropriate scientific base. In this context, the objective of this study was to verify the effect of the leaf spray fertilization of B and Zn on productivity and fruit quality of Japanese pear tree. The experiment was conducted from 2004 to 2005, in Ilha Solteira, in northwestern São Paulo State-Brazil. The climate is, according to the Köpppen Classification, tropical wet and dry (Aw). The 'Okusankichi' cultivar, grafted on Pyrus communis L. rootstock was used as well as doses of 110 g.ha-1 of B and 250 g.ha-1 of Zn in each application. The treatments were: T1. water, T2. boric acid, T3. zinc sulfate, T4. T2 + T3, T5. boric acid + urea + citric acid + EDTA, T6. zinc sulfate + urea + citric acid + EDTA, T7. T5 + T6, T8. boric acid + urea + citric acid + EDTA + sodium molibdate + sulfur + calcium chloride, T9. zinc sulfate + urea + citric acid + EDTA + Fe sulfate + Mn sulfate + Mg sulfate and, T10. T8+T9. A randomized blocks design was used and the averages were compared by Tukey test. In the first crop the mixture of boric acid with quelating agents were efficient to supply B to the plants and zinc sulfate plus quelating agents were efficient to increase Zn leaf content. However, the productivity and the fruit quality were not influenced by the leaf spray of B and Zn. In the second crop the leaf content of B and Zn and the productivity were not influenced by the leaf spray; the boric acid and the zinc sulfate with or without quelating agents increased the contents of total soluble solids and, the boric acid with or without quelating agents increased the contents of total titratable acidity.

Fig tree orchard formation using organic fertilization

The present work aimed at evaluating the effects of cattle manure fertilization on the growth and yield of fig trees. The cultivar 'Roxo de Valinhos' was used. One-, two-, three-and four-year-old trees were treated with cattle manure containing 0, 25, 50, 75, 100, 125 and 150% of the recommended nitrogen level per plant. The experiment was carried out using randomized blocks with 7 treatments, 5 replicates and 5 plants per experimental plot. The evaluated characteristics were: plant height, stem diameter, secondary branch length and diameter, yield per plant (kg plant-1), besides some quality characteristics of fruits such as pH, titratable acidity, soluble solids and texture. Manure application enhanced plant growth and fruit production. Significant differences were observed only for soluble solids content, pH and texture, which varied according to the crop cycle. After four crop cycles (2002/03, 2003/04, 2004/05 and 2005/06), the best results (about 5.0 kg of fruits per plant) were obtained with 100% of the recommended nitrogen dose, which corresponded to 14.3 kg of cattle manure per plant, in the last crop cycle (2005/2006).

Phosphorus and potassium budget in the soil-plant system in crop rotations under no-till

Soil management and crop rotations can affect P and K budget in soil, decreasing losses, and increasing fertilizer use efficiency. The P and K budget in the soil-plant system at depths up to 60. cm was studied for different soil managements and crop rotations under no-till for three years in Botucatu, São Paulo, Brazil. The investigated crop rotations were: triticale (X Triticosecale) and sunflower (Helianthus annuus) cropped in autumn-winter; pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor), and Sunn hemp (Crotalaria juncea) were grown in the spring, as well as an additional treatment with chiseling followed by a fallow period; and soybean (Glycini max, L., Merril) was cropped in the summer. Each year triticale and sunflower were grown in plots and pearl millet, forage sorghum, Sunn hemp and of chisel/fallow in sub-plots. The triticale/millet rotation led to the largest decrease in available P within the 0-0.60. m layer of the soil profile and the largest K increase within the 0-0.05. m layer. Potassium mobility in the soil profile and the increases in the available K content in the 0.40-0.60. m layer were independent of the management system. Crop rotations with or without chiseling are not effective in preventing soil P losses. There is considerable K leaching below 0.60. m, but chiseling and the use of high K accumulating plants as triticale results in lower K losses. © 2012 Elsevier B.V.

Quantification of uncertainties associated with space-time estimates of short-term soil CO2 emissions in a sugar cane area

The characterization of soil CO2 emissions (FCO2) is important for the study of the global carbon cycle. This phenomenon presents great variability in space and time, a characteristic that makes attempts at modeling and forecasting FCO2 challenging. Although spatial estimates have been performed in several studies, the association of these estimates with the uncertainties inherent in the estimation procedures is not considered. This study aimed to evaluate the local, spatial, local-temporal and spatial-temporal uncertainties of short-term FCO2 after harvest period in a sugar cane area. The FCO2 was featured in a sampling grid of 60m×60m containing 127 points with minimum separation distances from 0.5 to 10m between points. The FCO2 was evaluated 7 times within a total period of 10 days. The variability of FCO2 was described by descriptive statistics and variogram modeling. To calculate the uncertainties, 300 realizations made by sequential Gaussian simulation were considered. Local uncertainties were evaluated using the probability values exceeding certain critical thresholds, while the spatial uncertainties considering the probability of regions with high probability values together exceed the adopted limits. Using the daily uncertainties, the local-spatial and spatial-temporal uncertainty (Ftemp) was obtained. The daily and mean emissions showed a variability structure that was described by spherical and Gaussian models. The differences between the daily maps were related to variations in the magnitude of FCO2, covering mean values ranging from 1.28±0.11μmolm-2s-1 (F197) to 1.82±0.07μmolm-2s-1 (F195). The Ftemp showed low spatial uncertainty coupled with high local uncertainty estimates. The average emission showed great spatial uncertainty of the simulated values. The evaluation of uncertainties associated with the knowledge of temporal and spatial variability is an important tool for understanding many phenomena over time, such as the quantification of greenhouse gases or the identification of areas with high crop productivity. © 2013 Elsevier B.V.

Phosphorus and potassium balance in a corn-soybean rotation under no-till and chiseling

Nutrient use efficiency has become an important issue in agriculture, and crop rotations with deep vigorous rooted cover crops under no till may be an important tool in increasing nutrient conservation in agricultural systems. Ruzigrass (Brachiaria ruziziensis) has a vigorous, deep root system and may be effective in cycling P and K. The balance of P and K in cropping systems with crop rotations using ruzigrass, pearl millet (Pennisetum glaucum) and ruzigrass + castor bean (Ricinus communis), chiseled or not, was calculated down to 0.60 m in the soil profile for 2 years. The cash crops were corn in the first year and soybean in the second year. Crop rotations under no-till increased available P amounts in the soil-plant system from 80 to 100 %, and reduced K losses between 4 and 23 %. The benefits in nutrient balance promoted by crop rotations were higher in the second year and under without chiseling. Plant residues deposited on the soil surface in no-till systems contain considerable nutrient reserve and increase fertilizer use efficiency. However, P release from ruzigrass grown as a sole crop is not synchronized with soybean uptake rate, which may result in decreased yields. © 2013 Springer Science+Business Media Dordrecht.

Cover crops and no-till effects on physical fractions of soil organic matter

Physical fractions (free light fraction, intra-aggregate light fraction and heavy fraction) of soil organic matter (SOM) are good indicators of soil quality for sustainable land use. The objective of this study was to evaluate the effect of cover crops on total organic carbon (TOC) and physical fractions of soil organic matter in soil under a no-tillage system (NTS) and a conventional tillage system (CTS, one plowing and two disking). A three-year field experiment was carried out as a cover crop-rice (Oryza sativa)-cover crop-rice rotation. Treatments included cover crops (Panicum maximum, Brachiaria ruziziensis, Brachiaria brizantha, and pearl millet (Pennisetum glaucum), fallow, till or no till. The SOM was physically fractionated in free light fraction (FLF), intra-aggregates light fraction (IALF) and heavy fraction (HF). The levels of C in whole soil were also evaluated, as well as C in the light fractions (FLF+IALF) and in the HF. Results indicated that concentrations of C in the FLF and IALF in surface soils (0-0.05m) were much higher (10.8 and 1.95gkg-1, respectively) than that in the 0.05-0.1m soil depth (7.68 and 1.54gkg-1, respectively) and in the 0.1-0.2m soil depth (4.98 and 1.24gkg-1, respectively). The NTS resulted in higher levels of FLF (12.2gkg-1) and IALF (2.19gkg-1) than with CTS (1.37-7.30gkg-1). Millet had the highest C (19.5gkg-1) and N (1.1gkg-1) concentrations in soil. There was an accumulation of TOC and total N in the surface soil with cover crops, and concentrations of TOC were higher in the HF (79.0%) than in the light fractions (21.0%). Although SOM changed little during the two years of this experiment, the various C fractions were significantly affected by the tillage treatments. We conclude that SOM physical fractionation allowed seeing significant differences caused by the soil management in the organic matter dynamics in a short period of time. © 2013 Elsevier B.V.

Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC) and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp.) residues to the short-term CO2-C loss, we studied the infl uence of several tillage systems: heavy offset disk harrow (HO), chisel plow (CP), rotary tiller (RT), and sugarcane mill tiller (SM) in 2008, and CP, RT, SM, moldboard (MP), and subsoiler (SUB) in 2009, with and without sugarcane residues relative to no-till (NT) in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47% and 41%, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

Impact of the timing and duration of weed control on the establishment of a rubber tree plantation

A produção da seringueira é reduzida pelas plantas daninhas que competem por recursos ambientais; portanto, a época e duração do controle de plantas daninhas influencia a interferência das plantas daninhas. Os objetivos deste estudo foram: avaliar o crescimento de plantas de seringueira (Hevea brasiliensis), determinar o período crítico para controle das plantas daninhas e avaliar a recuperação do crescimento das seringueiras que conviveram com plantas daninhas por diferentes períodos de tempo após o plantio. Dois grupos de tratamentos foram estabelecidos em condições de campo, no primeiro ano de investigação: um grupo conteve períodos crescentes de infestação de plantas daninhas, enquanto o outro conteve períodos crescentes de controle das plantas daninhas, também incluindo uma testemunha livre de plantas daninhas e uma testemunha com infestação total de plantas daninhas. No segundo ano da investigação, as plantas daninhas foram totalmente controladas. Urochloa decumbens foi a planta daninha dominante (mais de 90% de cobertura). O crescimento da cultura foi grandemente reduzido devido à interferência de plantas daninhas. A altura de plantas decresceu mais rapidamente que qualquer outra característica. Altura de planta, massa seca de folhas e área foliar decresceram em 99%, 97% e 96%, respectivamente, e foram as características mais reduzidas. A altura de plantas também se recuperou mais rapidamente que qualquer outra característica quando o período de controle das plantas daninhas foi entendido. Contudo, a massa seca do caule aumentou em 750%, fazendo desta a característica mais recuperada. O período crítico para o controle de plantas daninhas foi entre 4 e 9½ meses após o plantio, no primeiro ano; contudo, as seringueiras mostraram expressiva recuperação do crescimento quando as plantas daninhas foram controladas ao longo do segundo ano.

Leaf synchrony and insect herbivory among tropical tree habitat specialists

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Soil microbiological attributes under summer/winter crops rotation in a no-tillage system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new probabilistic canopy dynamics model (SLCD) that is suitable for evergreen and deciduous forest ecosystems

There are strong uncertainties regarding LAI dynamics in forest ecosystems in response to climate change. While empirical growth & yield models (G&YMs) provide good estimations of tree growth at the stand level on a yearly to decennial scale, process-based models (PBMs) use LAI dynamics as a key variable for enabling the accurate prediction of tree growth over short time scales. Bridging the gap between PBMs and G&YMs could improve the prediction of forest growth and, therefore, carbon, water and nutrient fluxes by combining modeling approaches at the stand level.Our study aimed to estimate monthly changes of leaf area in response to climate variations from sparse measurements of foliage area and biomass. A leaf population probabilistic model (SLCD) was designed to simulate foliage renewal. The leaf population was distributed in monthly cohorts, and the total population size was limited depending on forest age and productivity. Foliage dynamics were driven by a foliation function and the probabilities ruling leaf aging or fall. Their formulation depends on the forest environment.The model was applied to three tree species growing under contrasting climates and soil types. In tropical Brazilian evergreen broadleaf eucalypt plantations, the phenology was described using 8 parameters. A multi-objective evolutionary algorithm method (MOEA) was used to fit the model parameters on litterfall and LAI data over an entire stand rotation. Field measurements from a second eucalypt stand were used to validate the model. Seasonal LAI changes were accurately rendered for both sites (R-2 = 0.898 adjustment, R-2 = 0.698 validation). Litterfall production was correctly simulated (R-2 = 0.562, R-2 = 0.4018 validation) and may be improved by using additional validation data in future work. In two French temperate deciduous forests (beech and oak), we adapted phenological sub-modules of the CASTANEA model to simulate canopy dynamics, and SLCD was validated using LAI measurements. The phenological patterns were simulated with good accuracy in the two cases studied. However, IA/max was not accurately simulated in the beech forest, and further improvement is required.Our probabilistic approach is expected to contribute to improving predictions of LAI dynamics. The model formalism is general and suitable to broadleaf forests for a large range of ecological conditions. (C) 2014 Elsevier B.V. All rights reserved.