Determinação da matéria seca e teores de macronutrientes em folhas de frutíferas usando diferentes métodos de secagem

O objetivo desse estudo foi avaliar diferentes métodos de secagem de folhas para três diferentes frutíferas (maracujá, pêssego e abacate), com relação à determinação da matéria seca e os teores foliares de macronutrientes. Foram coletadas amostras de folhas recém expandida de três culturas, do pomar da fazenda de ensino e pesquisa da FCAV-UNESP, câmpus de Jaboticabal, no mês de janeiro de 2010, coletando-se para cada cultura 12 amostras com 25 folhas cada. Os tratamentos constituíram-se por dois métodos de secagem, estufa de circulação de ar forçada regulada a uma temperatura de 70°C e o forno microondas (FMO). Avaliou-se a massa da matéria seca e os teores foliares de macronutrientes. Os resultados sugerem que os dois métodos de secagem testados se assemelham na determinação de matéria seca e nos teores foliares de macronutrientes para as culturas análisadas, exceto os teores de cálcio na cultura do pêssego.

Persea pumila (Lauraceae), a New Species from the Brazilian Serra da Mantiqueira Mountain Range

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aromatic compounds from three Brazilian Lauraceae species

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

Seasonal effects of foliar application of phosphonate on phosphonate translocation, in vitro pollen viability and pollen germination in `Hass' avocado (Persea americana Mill.)

Phosphonate fungicides are used widely in the control of diseases caused by Phytophthora cinnamomi Rands. For the most part phosphonate is seen as a safe to use on crops with phytotoxicity rare. However, recent research has shown that phosphonate has detrimental effects on the floral biology of some indigenous Australian plants. Since phosphonate fungicides are regularly used for the control of Phytophthora root rot in avocados, research was carried out to study the translocation of phosphonate fungicide in 'Hass' trees and any effects on their floral biology. Field-grown trees were sprayed with 0, 0.06 or 0.12 M mono-dipotassium phosphonate (pH 7.2) at summer flush maturity, floral bud break or anthesis. Following treatment, phosphonic acid concentrations were determined in leaves, roots, inflorescence rachi and flowers and in vitro pollen germination and pollen tube growth studied. Phosphonic acid concentration in the roots and floral parts was related to their sink strength at the respective times of application with concentration in roots highest (36.9.mg g±1) after treatment at summer flush maturity and in flowers (234.7 mg g±1) after treatment during early anthesis. Phosphonate at >0.03 M was found to be significantly phytotoxic to in vitro pollen germination and pollen tube growth. However, this rate gave a concentration far in excess of that measured in plant tissues following standard commercial applications of mono-dipotassium phosphonate fungicide. There was a small effect on pollen germination and pollen tube growth when 0.06 and 0.12 M mono-dipotassium phosphonate was applied during early anthesis. However, under favourable pollination and fruit set conditions it is not expected to have commercial impact on tree yield. However, there may be detrimental commercial implications from phosphonate sprays at early anthesis if unfavourable climatic conditions for pollination and fruit set subsequently occur. A commercial implication from this study is that phosphonic acid root concentrations can be elevated and maintained with strategic foliar applications of phosphonate fungicide timed to coincide with peaks in root sink strength. These occur at the end of the spring and summer flushes when shoot growth is relatively quiescent. Additional foliar applications may be advantageous in under high disease-pressure situations but where possible should be timed to minimize overlap with other significant growth events in the tree such as rapid inflorescence, and fruit development and major vegetative flushing.

Enhancing somatic embryogenesis in avocado (Persea americana Mill.) using a two-step culture system and including glutamine in the culture medium

The development of a more efficient in vitro regeneration system for somatic embryos (SEs) of avocado (Persea americana) would facilitate the development of new superior cultivars for this valuable horticultural crop. In this study, we report a new and efficient method for maintenance and regeneration of avocado SEs. Avocado SEs of four cultivars remained healthy and viable in vitro for 11 months on a medium used for mango somatic embryogenesis, compared with 3-4 months on Murashige and Skoog medium. Various supplements and media modifications were investigated to improve the low conversion rate of regenerated plants from avocado SEs reported previously. The one-step system for regeneration of white-opaque somatic embryos (WOSEs) used solid medium only over a period of 12-14 weeks (sub-culturing every 6 weeks). Addition of praline and glutamine improved the total regeneration from 0 to 17.5% and 10.5%, and plant/shoot recovery from 0 to 12.5% and 5%, respectively. A two-step culture system involving the transfer of WOSEs of cultivar 'Reed' after 6 weeks on solid to liquid medium for 12-15 days as an intermediate step, followed by subculturing again onto solid medium for 6 weeks improved total regeneration to 29% and plant/shoot recovery to 18.3 from 0% when regenerated by subculturing on solid medium only. Supplementation with proline in the solid as well as liquid medium in the two-step culture system at 0.4 g/L increased total regeneration to 35% and plant/shoot recovery to 20%. We were able to achieve highest regeneration using glutamine at 1 g/L in the two-step culture system in terms of both total regeneration (58.3%, including 43.3% bipolar regeneration) and plant/shoot recovery (36.7%) rates, which were significantly higher than in any other treatment investigated. (C) 2013 Elsevier B.V. All rights reserved.

Pau-rosa (Aniba rosaeodora Ducke) Lauraceae): informações sobre o sistema de plantio e o manejo sustentável da espécie.

Dados da espécie. Produtividade. Valor econômico. Produção de mudas e plantio de pau-rosa. Produção de biomassa. Produção de essência a partir de folhas e galhos.

Incidencia del manejo agronómico convencional y orgánico sobre la biodiversidad en sistemas productivos de aguacate (Persea americana Mill.) en el estado de Michoacán, México

La pérdida de la biodiversidad que genera la disminución de interacciones bióticas y procesos ecosistémicos es uno de los principales problemas ecológicos en la actualidad. Esta situación se ha relacionado a la simplificación de los sistemas naturales y a la intensificación de los sistemas productivos agrícolas, prácticas que incluso pueden ir en detrimento del rendimiento de los campos de cultivo. Sin embargo, las huertas podrían ser reservorios de biodiversidad y recursos alimenticios que provean hábitats de alta calidad para muchos organismos. En este trabajo, se relaciona el tipo de manejo agronómico (convencional y orgánico) en huertas aguacateras con la riqueza y la composición de las comunidades de visitantes florales, acarreadores de polen y plantas herbáceas con el fin de estudiar la diversidad asociada a dichos sistemas y la incidencia del manejo agronómico sobre estas comunidades. El trabajo se compone de 3 capítulos. El primer capítulo plantea la relación entre el manejo agronómico y la diversidad de visitantes florales y plantas herbáceas a partir de la generación de Unidades Básicas de Clasificación (UBC). En el segundo capítulo, se aborda la ecología reproductiva del aguacatero, en donde se estimó la oferta floral, la diversidad de la comunidad de visitantes florales y acarreadores de polen, su eficiencia de estos en el acarreo de polen y su contribución a la producción de frutos bajo el manejo agronómico orgánico y convencional. En el tercer capítulo, se construyeron y analizaron seis redes de interacción de polen acarreado-acarreador en dos momentos del cultivo: i) durante la floración del aguacatero y ii) en ausencia de floración del aguacatero. El estudio se llevó a cabo durante dos años consecutivos en el pico de floración 2010/2011 y 2011/2012 en 6 huertas orgánicas y 4 convencionales (...) Los resultados de este trabajo mostraron como el manejo agronómico puede influir en la estructura de la comunidad de visitantes, acarreadores de polen y herbáceas. Considerando que el cultivo del aguacatero presenta la floración en una época específica del año, es importante que existan de forma continua otros recursos florales para los acarreadores como son las herbáceas. Los recursos provenientes de estas plantas pueden mantener durante el año la funcionalidad de la comunidad de visitantes y acarredores, proporcionando el servicio ecosistémico de la polinización de plantas silvestres y de las cultivadas. A su vez, la tesis contribuye al fortalecimiento del conocimiento de patrones que proponen que la disponibilidad de recursos florales en las huertas derivados de manejos agronómicos más integrales y menos intensivos que favorecen el incremento de la riqueza de visitantes de flores y acarreadores de polen nativos