Análise econômica da bananeira "Pacovan Ken" em função de diferentes tensões de água do solo.

O trabalho avaliou economicamente a bananeira ?Pacovan Ken? sob diferentes tensões de água no solo, relacionando os custos de produção obtidos pela aplicação de água e as receitas alcançadas através da produtividade para cada tratamento. O experimento foi realizado em um solo tipo Cambissolo, em Limoeiro do Norte, Ceará, utilizando a cultivar Pacovan Ken irrigada por microaspersão. Os tratamentos consistiram em iniciar as irrigações quando a tensão da água na zona radicular da cultura (0-0,4 m) atingisse -15, -30, -45 e -60 kPa. Três sensores de resistência elétrica tipo matriz granular (modelo Watermark) foram instalados em cada parcela (0,15; 0,30 e 0,50 m). Nas avaliações de produção foram utilizadas quatro plantas situadas na fileira dupla central de cada parcela. Para cálculo do custo da irrigação (Ci) foi adotado apenas o custo de aplicação da água, considerando uma situação hipotética padrão para irrigação de uma área de 5,0 ha. A melhor relação custo/benefício encontrada para a cultivar de banana Pacovan Ken na região estudada foi obtida quando as irrigações eram iniciadas na tensão de água no solo de -15 kPa, apresentando uma menor sensibilidade à variação de preço do produto, além do maior índice de lucratividade

Animal Performance and Productivity of New Ecotypes of Brachiaria Brizantha in Brazil

Brazil has the competitive advantage of a very dynamic and cost effective animal production system on pastures over other countries. The pursuit for more productive forages that will result in higher quality beef at a lower cost is then justified. Brachiaria is the most important forage genus utilised in Brazil, thus an intense search for new cultivars amongst collected and introduced ecotypes from Africa is underway. Following agronomic evaluation of this material in plots, 8 pre-selected Brachiaria ecotypes were tested under intermittent grazing in paddocks (Euclides et al., 2001). Continuing on the process of cultivar development, two out of the eight, selected for superior agronomic characteristics were compared to the standard cultivar Marandu, under grazing and the results are presented in this paper

Carbon Accumulation in Soils under \u3ci\u3eBrachiaria\u3c/i\u3e Pastures in the Atlantic Forest Region of the South of Bahia, Brazil

The objective of this study was to investigate the change in carbon stocks in soil following deforestation of the Atlantic forest in the South of Bahia State (Brazil) and replacement with productive pastures of Brachiaria humidicola either in monoculture or with the introduction of the forage legume Desmodium ovalifolium. Carbon stocks in the 0-30 cm layer were 44.5 Mg ha-1 under the original forest and found to be approximately 42 Mg ha-1 C 10 years later. At this time pastures of B. humidicola with or without the presence of D. ovalifolium were formed and grazed continuously for a further nine years until 1997. To 30 cm depth, C stocks increased during this time to 49.3 Mg ha-1 in the grass-only pasture and 52.4 Mg ha-1 in the mixed pasture which suggests that the presence of the legume enhanced C accumulation under the Brachiaria pastures. Analysis of the 13C abundance of samples taken to 100 cm depth in 1997 revealed that there was significant accumulation of organic matter derived from the Brachiaria to a depth of 50 cm in the soil and this material was of high C:N ratio (22-27)

Uso de fungicidas e óleo de Piper aducun (dilapiol) para o controle de Colletotrichum musae.

A banana está entre as frutas mais produzidas e consumidas no Brasil. A antracnose (Colletotrichum musae) é a principal doença pós-colheita em frutos, porém, a infecção inicia no campo. O controle da antracnose é difícil, e o estudo de produtos químicos e alternativos que reduzam as infecções e seu progresso nos frutos é importante no manejo da doença

Cycling of N and P in Grass-Alone (\u3ci\u3eBrachiaria\u3c/i\u3e) and Mixed Grass/Legume (\u3ci\u3eBrachiaria/ Desmodium ovalifolium\u3c/i\u3e) Grazed Pastures in the Atlantic Forest Region of Brazil

There are estimated to be \u3e 80 M ha of Brachiaria pastures in the tropical regions of Brazil. When continuously grazed with only modest fertiliser inputs (and no N) these pastures can maintain reasonable cattle weight gains (\u3e 200 kg LWG/ha per year). However, without fertiliser and when overgrazed, LWGs fall rapidly to low levels. Recent studies have shown that N and P deficiency are the most important factors limiting productivity. The objective of this study was to study fluxes of N and P in the pasture system in order to understand resilience to poor management and minimum nutrient requirements to guarantee their sustainability

Forage Legume Presence and Grazing Intensity Effect on Nitrogen Dynamics in \u3ci\u3eBrachiaria\u3c/i\u3e Pastures in the South of Bahia, Brazil

The objective of this study performed in the Atlantic forest region of the South of Bahia (Brazil) was to examine the influence of the presence of the forage legume Desmodium ovalifolium in pastures of Brachiaria humidicola on the nitrogen recycled through plant litter over stocking rates of 2, 3 and 4 head ha-1. The results demonstrated that the presence of the D. ovalifolium in the pasture significantly increased the protein content of the associated Brachiaria grass, and the rate and quantity of N recycled through the litter pathway. While had no significant increase in animal weight gain due this legume, the increase in N recycled through the litter pathway should provide an increase in the sustainability of pasture production, especially at the lower stocking rate where the grazing pressure was lower and the proportion of legume was higher

Grazing intensity affects forage accumulation and persistence of Marandu palisadegrass in the Brazilian savannah.

This 3?year study evaluated the effects of grazing intensity on herbage and steer responses in continuously stocked Brachiaria brizantha cv. Marandu pasture in the Brazilian savanna. Treatments consisted of three grazing intensity levels, characterized by canopy heights of 15, 30 and 45 cm, measured twice per week. Responses variables included tiller population density (TPD), herbage accumulation rate (HAR) and body weight gain per area (WGA). A decline in TPD (1,237 vs. 767 tillers/m2) was observed from the first to the third grazing years, which influenced the HAR from the first to the third years (90.1 vs. 52.4 kg ha?1 day?1). A marked decline in body WGA (541 vs. 276 kg ha?1 year?1) was observed along the three years in pastures managed at a height of 15 cm, indicating that this is an unstable condition for Marandu palisadegrass pasture. HAR was similar for pastures managed at 30 or 45 cm and was relatively stable during the experimental period, averaging 91.8 and 99.1 kg ha?1 day?1 respectively. Body WGA was similar and constant throughout the experimental period for pastures managed at 30 (596 kg ha?1 year?1) and 45 cm (566 kg ha?1 year?1). Maintaining continuously stocked Marandu palisadegrass pastures at a 15 cm canopy height should be avoided due to long?term decreases in plant persistence and animal body WGA, particularly when soil P is below critical levels at pasture establishment and during pasture utilization