Germinação de sementes de araca-boi (Eugenia stipitata Mc Vaugh) submetidas a diferentes métodos de armazenamento e períodos de conservação.

O objetivo do presente trabalho foi estudar a germinação de sementes de araca-boi, sob dois métodos de armazenamento e quatro períodos de armazenamento.bitstream/item/74492/1/AP-1998-Germinacao-sementes-araca-boi.pd

Production and vegetative growth of coffee trees under fertilization and shade levels

It is difficult to separate the effects of light reduction versus nutrient and water competition in agroforestry systems. The objective of this experiment was to evaluate the effect of shading and fertilizer supply on the vegetative development and yield of Coffea arabica over six years. The coffee trees were covered with shade screens (photosynthetically active radiation reduction up to 48%) and fertilized from 100 to 40% of the recommended amount from 2001 on. Leaf area, number of leaves, number of nodes, leaf area per branch and, yield were determined. Although no effect of fertilization was found, shading influenced the number of nodes, leaf area and production from the third year on. The number of nodes and yield decreased as shading increased. The effect of the yield bienniallity was more evident in the unshaded trees, which yielded an average of 2,646 kg ha¹. The trees under 48% shading yielded an average of 2,094 kg ha¹. After 2004 the leaf area per branch increased as the shade increased, at the end of both the maximum and minimum growth periods. During the first three years, the coffee trees do not change their vegetative or productive characteristics as a response to shading. The shade effects become more intense after the beginning of the higher yield period. The shaded coffee trees have a larger leaf area and a smaller number of nodes than the coffee trees under full sun. The yield decreases as photosynthetically active radiation limitation increases, and yield bienniallity is less intense in shaded trees.Em sistemas agroflorestais é difícil separar os efeitos da competição por luz daquela por água e nutrientes. O objetivo do experimento foi avaliar o efeito do sombreamento e do fornecimento de fertilizantes sobre o desenvolvimento vegetativo e a produtividade de cafeeiros arábica ao longo de seis anos. Os cafeeiros foram cobertos com telas sombreadoras (redução da radiação fotosinteticamente ativa em até 48%) e fertilizados de 100 até 40% da recomendação. Foram determinados a área da folha, o número de folhas, o número de nós, a área foliar por ramo e a produtividade dos cafeeiros. Embora não houvesse efeito da fertilização, o sombreamento influenciou o número de nós, a área da folha e a produção a partir do terceiro ano. O número de nós e a produtividade reduziram conforme aumentou o sombreamento. Cafeeiros sob pleno sol apresentaram maior bienalidade da produção e produtividade média de 2646 kg ha¹. Cafeeiros sob 48% de sombreamento produziram em média 2094 kg ha¹. Após três anos a área foliar aumentou com o aumento do sombreamento, tanto no final do período de maior quanto de menor crescimento. Nos três primeiros anos, os cafeeiros não diferiram nas características vegetativas ou reprodutivas devido ao sombreamento. Os efeitos do sombreamento tornam-se mais intensos após o início do período de altas produtividades. Cafeeiros sombreados apresentam folhas maiores e menor número de nós do que cafeeiros sob pleno sol. Nos anos de alta produtividade esta decresce com o aumento do sombreamento e a bienalidade é menos intensa nos cafeeiros sombreados

Improving the outcomes of community forests in Suriname - Recommendations for CSOs

As part of a multi-country review of community forest rights, Tropenbos Suriname conducted a review of the community forests in Suriname, to understand the extent to which they result in positive conservation and livelihood outcomes, and to identify the conditions for their success and ways in which Civil Society Organisations (CSOs) can help with achieving these. In this policy brief we summarize some of the main outcomes of the review, and the consequent recommendations for CSOs

Estudios ecol?gicos de ra?ces en sistemas agroforestales: experiencias metodol?gicas en el CATIE

Ilus. Tab. Glo. p. iii. Bib. p. 22-2

Human papillomavirus in malignant cervical lesions in Surinam, a high-risk country, compared to the Netherlands, a low-risk country

In various countries epidemiologic studies show an association between human papillomavirus (HPV) and cancer of the uterine cervix. We determined the presence of HPV and the distribution of the different HPV genotypes in cervical carcinomas from Surinam, a high-incidence country. The results were compared to the Netherlands where the incidence is five times lower. One hundred thirty cervical carcinomas from patients in Surinam were randomly selected and compared to an unselected group of 128 cervical carcinomas from caucasoid Dutch patients. Presence of HPV and distribution of HPV genotypes was determined in DNA extracted from paraffin-embedded specimens by polymerase chain reaction and sequence analysis. HPV DNA was detected in 82% of the Surinamese cervical cancer patients and in 87% of the Dutch patients. Thirteen different HPV genotypes were detected in the Surinamese group, and nine different HPV genotypes were detected in the Dutch group. Among the HPV-positive samples, HPV 16 was present in 68% in the Netherlands compared to only 49% in Surinam, where less common genotypes such as HPV 35, 45, and 58 were more prevalent. The results show a strong association between HPV and cervical cancer in both groups. However, the observed significant variation in distribution of the genotypes in the two populations with a large difference in cervical carcinoma incidence is important to the general understanding of the etiology of cervical cancer and to the development of HPV vaccination strategie

Agroforestry in the Amazon Region: A Pathway for Balancing Conservation and Development

This chapter argues for a broader conceptual domain provided by agroforestry practices as a key pathway for the reorientation of agricultural systems in the Amazon toward modes of production that combine productivity and sustainability. A contextualization of the multiple expressions of current agroforestry development in the Amazon shows that, contrasting with homegardens and shifting cultivation, ubiquitous in the region, planned or organized agroforestry systems are still minor elements of the agricultural landscape, often arising from farmers’ experimentation or resulting from initiatives funded by international cooperation. A “multichain” approach focusing on both established markets as well as “secondary chains” is suggested as a pathway for agroforestry to go beyond subsistence toward income generation and to reduce the constraints faced by Amazon farmers to intensify land use. The costs and risks presented by practices leading to intensification, aggravated by problems in regional infrastructure, limited access to adequate technical and financial services, and insecure land tenure require equitable development policies and programs to support such initiatives. A stronger policy identity for agroforestry in the region should thus recognize the provision of both economic goods and ecosystem services, and this chapter argues that given the carbon stored in agroforestry systems, the framework of environmental international agreements is an opportunity to combine environmental and livelihood benefits through the design, promotion, and dissemination of agroforestry strategies. A review of policies that can influence adoption of sustainable land use systems in the Amazon region attests their operation in a fragmented manner. These policies must be set as a cohesive whole, being agroforestry the common thread to support and link initiatives to reduce poverty and hunger, curb deforestation and CO2 emissions, and to mitigate climate change. Agroforestry will be then an effective strategy to bridge gaps between policies, and particularly in linking environmental opportunities with economic realities, while enhancing the livelihoods of smallholders, traditional communities, and indigenous peoples in the Amazon

Shade trees and tree pruning alter throughfall and microclimate in cocoa (Theobroma cacao L.) production systems

Shade trees in agroforestry systems protect the understory cocoa from climate extremes. Shade tree pruning manages microclimatic conditions in favor of cocoa production while tree diversity is maintained. Adaptation of pruning has to consider seasonal changes in temperature and precipitation to protect the understory cocoa. Context Structural characteristics of tree stands such as species diversity, tree density, and stratification can affect throughfall and microclimate. Pruning changes the canopy and may therefore modulate internal conditions. Aims The aim of this study is to assess the environmental growing conditions of cocoa trees. Methods We monitored canopy openness and the impact of stand structure on throughfall and microclimate in three cocoa production systems (monoculture, agroforestry, and successional agroforestry) and a natural regrowth in a long-term trial in Bolivia from 2013 to 2015. We further focused on the effect of annual shade tree and cocoa pruning on these variables to evaluate the potential impact of this activity. Results Agroforestry systems buffered extreme climate events like temperature fluctuations compared to monocultures but reduced light and throughfall drastically. Spatial variability of throughfall and transmitted light were low under a high and closed shade tree canopy. Shade tree pruning resulted in higher canopy openness, light transmittance, and throughfall, while the buffer function of the agroforestry systems concerning temperature and humidity fluctuations was reduced. Conclusion Differences between cocoa production systems regarding throughfall and microclimate were overlain by pruning activities. Cocoa agroforestry systems are temporal dynamic systems. Pruning timing and intensity is pivotal for balancing light and water availability under seasonally varying environmental conditions to conserve micro-environments for cocoa production with less exposure to unfavorable climate