Search

The bronzing disease of Thai jackfruit (Artocarpus heterophyllus Lam.) has recently appeared in Vietnam, causing a significant loss for farmers, but its control method is still restricted. In this study, we identified pathogens based on morphological and molecular characterizations. A total of 25 bacterial isolates were isolated from diseased samples. The bacterium produces white or yellow pigment in culture, is gram-negative, slightly pleomorphic, non-motile, facultatively anaerobic, short-rod, and catalase-positive. It hydrolyzes gelatin and starch but not tween 80, and produces acid from glucose, sucrose, and lactose. The bacterium does not produce indole and does not produce hypersensitivity to tobacco. The results of sequencing of the encoded region of synthesis of capsular polysaccharide (cpsD) and pathogenicity-related genes HrpS confirmed that the causative agent is Pantoea stewartii subsp. stewartii. The pathogen's possible host range could be traditional jackfruit varieties, fruits, and crops such as durian, longan, mango, tomatoes, broccoli, pumpkin, cucumber, corn, rice, sweet potatoes, water spinach, peanuts, and green beans. The P. stewartii subsp. stewartii could enter the host plant cell through open wounds or natural openings such as stomata. The results confirmed the presence of P. stewartii subsp. stewartii in Vietnam and suggest that the jackfruit tree should not be planted in plantations with these crops to prevent cross-contamination and the spread of pathogens. [ABSTRACT FROM AUTHOR]

Coconut (Cocos nuciferaL.) is a multipurpose plantation crop with versatile uses, including as a refreshing drink, edible oil, and, nutraceuticals. Its nutraceutical properties have increased demand in global markets. However, coconut productivity remains low owing to inadequate improved planting materials. This challenge has created a high demand and low supply gap in the coconut industry, which needs to be addressed through breeding methods that can increase productive cultivars in a shorter time. Breeding methods, such as mass selection and hybridization between dwarf and tall cultivars, are the main coconut improvement methods because of their simplicity and ease of use. The hybrids produced, however, take a long time (4-6 years) to bear fruits due to genes inherited from tall parents. Dwarf hybrids that bear fruits in a shorter time (3 years) are less exploited. Developing these coconut types through efficient breeding methods can fill the supply and demand gaps created in the coconut industry. Marker-assisted selection and multi-omics, have been used to identify quantitative traits of agronomic importance to increase genetic gains in dwarf coconut cultivars. This review article summarizes the advances in coconut improvement through conventional breeding, marker-assisted selection, and multi-omics approaches, focusing on dwarf coconut cultivars. [ABSTRACT FROM AUTHOR]

Bird‐ and bat‐mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for pest biocontrol. We used a full‐factorial experiment excluding birds, bats, and ants to assess their effects on (a) the abundance of multiple arthropod groups; (b) predation pressure on arthropods evaluated through artificial sentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestry systems of native cacao varieties in Peru. Birds and bats increased cacao yield by 118%, which translates in smallholder benefits of ca. US $959 ha−1 year−1. Birds and bats decreased predation by ants and other arthropods, but contributed to the control of phytophagous taxa such as aphids and mealybugs. By contrast, ant presence increased the abundance of these sap‐sucking insects, with negative impacts for cacao yield. Notably, high abundances of the dominant ant Nylanderia sp., known to attend sap‐sucking insects, were associated with lower cacao yield along a distance gradient from the closest forest edge. According to these results, arthropod predation by birds and bats, rather than mesopredation by arthropods, was most responsible for increases in cacao yield. Moving forward, detailed research about their trophic interactions will be necessary to identify the cause of such benefits. Retaining and restoring the large benefits of birds and bats as well as minimizing disservices by other taxa in cacao agroforests can benefit from management schemes that prioritize preservation of shade trees and adjacent forests within agroforestry landscapes. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Unmanned aerial vehicle (UAV) sprayers are widely utilized in commercial aerial application of plant protection products (PPPs) in East Asian countries due to their high flexibility, high efficiency and low cost, but spray drift can lead to low utilization of UAV sprayers application, environmental pollution and bystander exposure risk. Droplet size and spray volume are critical factors affecting spray drift. Currently, the high temperature and humidity environment under the influence of the tropical monsoon climate brings new challenges for UAV sprayers. Therefore, in this study, pesticides were simulated with seduction red solution, and spraying trials were conducted using the DJI commercial T40 UAV sprayers for a typical tropical crop, coconut. In this study, the spray drift distribution of droplets on the ground and in the air, as well as the bystander exposure risk, were comparatively analyzed using droplet size (VF, M, and C) and spray volume (75 L/hm2 and 60 L/hm2) as trial variables. The results indicated that the spray drift characteristics of UAV sprayers were significantly affected by droplet size and spray volume. The spray drift percentage was negatively correlated with the downwind distance and the sampling height. The smaller the droplet size, the farther the buffer zone distance, up to more than 30 m, and the cumulative drift percentage is also greater, resulting in a significant risk of spray drift. The reduction in spray volume helped to reduce the spray drift, and the cumulative drift percentage was reduced by 73.87 % with a droplet size of M. The region of the body where spray drift is deposited the most on bystanders is near chest height. This study provides a reference for the rational and safe use of multirotor UAV sprayers application operations in the tropics and enriches the spray drift database in the tropics. • Field trials were designed to investigate the risk of environmental and bystander exposure from UAV sprayers. • The spray drift risk of UAV sprayers was assessed for different operational parameters (droplet size and spray volume). • Drift deposition and bystander exposure negatively correlated with downwind distance/height. • The risk of spray drift can be effectively reduced by varying the operating parameters of the UAV sprayer. [ABSTRACT FROM AUTHOR]

[Display omitted] Oil palm (Elaeis guineensis Jacq.) is of the most profitable and widespread commercial high tree crops in the tropical world, typically in Southeastern Asia. The present study aims to provide a brief but broad overview of different applications of expert systems (ESs) in oil palm precision agriculture (PA), focusing on the three main generic categories: crop, water, and soil management. This study is meant to review research articles from the past decade: 2011–2020. Based on the search strategy alongside the inclusion criteria, 108 articles were included for synthesis activity. The findings of the study reveal patterns, networks, relationships, and trends in the application of ESs in oil palm PA in the past decade. The broad insight obtained from the synthesis activity was used to identify the possible roads ahead in oil palm PA. The findings of this study could be useful and beneficial to the research community and stakeholders in identifying the progress and trends of ESs in oil palm PA in the past decade, help to gain a holistic view on research gaps, potential markets, relevant advantages, the roads ahead, and contributing to further systematic research (deepen or broaden) in this topic. [ABSTRACT FROM AUTHOR]

Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a tropical legume crop found in Southeast Asian countries including Thailand. The mature seeds have high protein content and have been targeted as a protein source, and germination has been used to increase the value of nutrition. We used nanoLC/timsTOF Pro 2 combined with PEAKS® studio Xpro software to explore the proteomes of mature seeds and sprouts of purple winged bean. This study is the first report on the allergenic proteins in mature seeds and sprouts of purple winged bean. In silico analysis using Allergen Nomenclature search and the Allermatchtm program, 37 allergens were found. Conglutin beta 5 and late embryogenesis abundant protein (3 and D-29) were identified only in mature seeds, while 4 types of major pollen allergen Bet V, profilin and isoflavone reductase, were identified only in sprouts. Examples of allergens in both samples include basic 7S globulin, beta-conglycinin alpha/beta subunit (1,2), convicilin, defensin-like protein, 7 types of non-specific lipid-transfer protein, P24 oleosin isoform B. Since food allergy and airway allergy are found in sprouts, we used shotgun proteomics and in silico analysis for detecting the profiles of allergens. With regards to food safety, purple winged beans may also induce cross-reactivity in patients who are allergic to peanuts or other legumes. Therefore, identifying the proteomes and potential allergens in mature seeds and sprouts of purple winged beans could assist researchers in studying plant-based food safety. [Display omitted] • The first report of allergen detection in mature seeds and sprouts of purple winged bean. • In silico analysis revealed 37 allergens in mature seeds and sprouts of purple winged bean. • The detected food allergens were associated also with peanuts and other legumes. • Airway allergens were only found in sprouts of purple winged bean. [ABSTRACT FROM AUTHOR]

• The social science of plantation crops needs to trace the intimate relations of people and plants. • The imperial crop hypothesis seeks to draw attention to intrinsic aspects of plants. • The Assam tea plant with large leaves was key to the success of British tea. • Small-scale tea production opens a space for the decolonization of tea. • Indigenous cultivation of tea in the forest is the climate smart alternative. The cultivation of tea has had major impact on societies and environments across the world. It has been the cause of imperial wars, colonial appropriations of territories and capitalist exploitation of people and ecologies. In this article, I am particularly concerned with the British empire of tea, what preceded it and its afterlife in the former colonies. Research on tea within the social sciences and humanities have mainly concentrated on the precarious situation of plantation laborers. Informed by recent scholarship in multispecies- and critical plant studies, I seek to trace the intimate relations between people and plants. Taking a cue from James C. Scott's "grain hypothesis," I suggest an "imperial crop hypothesis" asking if there are any particular attributes of the tea plant that lend itself to imperial ambitions. In this I straddle between a political ecology concerned with power, resources and infrastructures that enabled the British to establish its empire of tea, and a multispecies approach that foregrounds the entangled ecologies of plant life. I concentrate on four particular moments of this history: the British "discovery" of tea grown by indigenous peoples in the hills of the newly annexed Ahom kingdom in the early 19th century; the establishment of the Assam plantations during second half of the 19th century; the travel of tea across the Indian Ocean and the making of Kenyan tea industry during the 20th century; and, finally, the development of purple tea, a new variety of tea projected as the tea plant for the 21st century. [ABSTRACT FROM AUTHOR]

Background: Durian (Durio zibethinus L.) is a tropical fruit crop which is popular in Southeast Asia but recently gaining popularity in other parts of the world. In this study, we analyzed the resistance gene analogs (RGAs) of durian through mining of the currently available reference genome of its 'Musang King' cultivar (PRJNA400310). Results: A total of 2586 RGAs were identified in the durian genome consisting of 47 nucleotide binding site proteins (NBS), 158 NBS-leucine rich repeat proteins (NL), 400 coiled-coil NBS-LRR (CNL), 72 toll/interleukin-1 receptor NBS-LRR (TNL), 54 coiled-coil NBS (CN), 10 toll/interleukin-1 receptor NBS (TN), 19 toll/interleukin-1 receptor with unknown domain (TX), 246 receptor-like proteins (RLP), 1,377 receptor-like kinases (RLK), 185 TM-CC, and 18 other NBS-containing proteins with other domains. These RGAs were functionally annotated and characterized via gene ontology (GO) analysis. Among the RGAs with the highest copies in durian genome include the putative disease resistance RPP13-like protein 1, disease resistance protein At4g27190, disease resistance protein RPS6, Probable disease resistance protein At4g27220, and putative disease resistance protein RGA3, while 35 RGAs were found to be novel. Phylogenetic analyses revealed that the genome-wide RGAs were broadly clustered into four major clades based on their domain classification. Conclusion: To our knowledge, this is the most comprehensive analysis of durian RGAs which provides a valuable resource for genetic, agronomic, and other biological research of this important tropical fruit crop. [ABSTRACT FROM AUTHOR]

Glycine max (L) soybean (Merr) is the world's most widely produced and consumed oilseed. Since its establishment in Brazilian fields, the sweetpotato whitefly Bemisia tabaci (Gennadius 1899) Hemiptera: Aleyrodidae became a notorious pest in soybean fields. However, there is not a sampling plan specifically designed to scout B. tabaci adults in tropical soybean crops. Hence, this study aimed to develop a standardized sampling plan for scouting B. tabaci adults in tropical agriculture. This study was conducted in commercial soybean fields in the Brazilian Savanah from 2017 to 2021, encompassing the vegetative, flowering, and fruiting stages. B. tabaci adults were evaluated to establish a conventional sampling plan, following a five-step approach: (i) determination of the appropriate sample unit, (ii) sampling technique evaluation, (iii) analysis of the frequency distribution of B. tabaci were evaluated to establish a conventional sampling plan, following a five-step approach density, (iv) calculation of the optimal number of samples, and (v) assessment of costs and sampling time. The apical part of the soybean canopy was the ideal sampling unit for assessing B. tabaci populations throughout the plant cycle. Beating the apical part of the plant against a plastic tray proved to be the most suitable sampling technique. A total of 49 samples per field were required to effectively scout this pest. The sample process lasted no more than 5 min per hectare, and the associated costs did not exceed US$ 0.74 per hectare. These results provide the first precise and representative standardized sampling plan to scout B. tabaci adults in tropical soybean fields. [Display omitted] • The first standardized sampling plan to scout B. tabaci adults in soybean fields. • The ideal sampling unit to scout whitefly is the apical part of the soybean plant. • Whitefly sampling technique was beating the soybean plant against a plastic tray. • The number of soybean plants demanded to scout whitely was 49 samples per field. [ABSTRACT FROM AUTHOR]

• We explore the fraught practices of ecological civilization in Yunnan. • Development is constituted by diverse, situated interests, pursuits and relations. • Maca commercialization involves complex discourses and practices of nature. • Farmers evolved from recipients of development to agricultural entrepreneurs. In this paper we argue that research on development in frontier regions needs to incorporate an explicitly environmental and ecological dimension, because economic frontiers are increasingly regarded as ecological frontiers in state and public discourses alike. We elaborate this argument by examining how the state-capital coalition has intervened in the development of Yunnan, a southwestern frontier of China, and how this process has involved the construction of an ecological civilization. This paper conceptualises the campaign of ecological civilization as the performance of state power through the discourses and practices of nature, and in this process, development is a highly situated and contingent process entangled with the complex negotiations between the state's ambition of socio-political assimilation, the volatility of the market and the agency of local communities. In specific, we focus on economic and ecological practices of using land for the plantation of the commercial crop maca. In the past decade or so, maca production in Yunnan has undergone a drastic process of rapid expansion and subsequently an equally rapid decline. Local authorities colluded with large enterprises to domesticate maca and promote maca production for land-based capital accumulation and poverty alleviation. Meanwhile, local farmers underwent a transformation, albeit contested, incomplete and full of back and forth, from passive recipients of development to active agricultural entrepreneurs. This article advances debates on frontier development and the role of nature in such processes, through the specific lens of ecological civilization in contemporary China. [ABSTRACT FROM AUTHOR]

The betel vine (Piper betle L.) is one of the plantation crops commercially cultivated for its leaf in South and Southeast Asia. The leaf production is often threatened by different insect pests including Aleurocanthus rugosa Singh (Hemiptera: Aleyrodidae). Currently, infestations of A. rugosa in betel vine are primarily controlled using excessive conventional broad-spectrum chemical pesticides that pose serious human health risks due to the masticatory nature of consumption. This study was carried out to investigate the performance of colored sticky traps and biopesticides against A. rugosa as an ecofriendly approach by conducting multilocation field trials from 2019 to 2021. It was observed that the A. rugosa population prevailed throughout the year, however, insect infestation was higher in May and October due to the high temperature. Among the sticky traps, A. rugosa was highly attracted to the yellow-colored traps compared to white or blue traps. Whereas alternating sprays of either D-lemonine (Bio clean® 5% SL) or spinosad (Success® 2.5% SC) with sodium lauryl ether sulphate (Fizimite® 10%) reduced the A. rugosa population by 71.4–79.0% over control. Further, a combination of these spray regimes with yellow-colored sticky traps as IPM packages showed improved results in reducing pest populations by 83.8–86.0% and increasing leaf yield by 60.4–63.6% over control. Even the performance of the IPM packages was better than farmers' practice i.e., broad-spectrum chemical pesticides. Thus, the outcome of this study indicates that the IPM program could be a sustainable and environmentally friendly method of controlling A. rugosa in betel vine production. [Display omitted] • Aleurocanthus rugosa in betel vine appears throughout the year with peaks in May and October. • Yellow colored sticky trap is more effective to capture A. rugosa adult. • Alternate spraying of D-Lemonine or Spinosad with sodium lauryl ether sulphate are effective to control A. rugosa. • Yellow colored sticky traps with spraying of biopesticides are an effective IPM package against A. rugosa. [ABSTRACT FROM AUTHOR]

Biogas slurry is a nutrient-rich secondary product of livestock feces digestion which is recycled as a crop plantation fertilizer and provides exogenous microbes to the soil. However, the effects of biogas slurry microbes on the soil resident community remain unknown. In this study, we examined the ecological consequences of long-term biogas slurry pulse on the soil resident community and found that it promoted crop yield and altered soil characteristics. The soil microbial ecosystem was altered as a result of organic amendments due to the exogenous input of microbes and nutrients. Nevertheless, the soil resident communities were highly resilient to long-term organic pulses, as evidenced by community diversity and composition. The two dominant bacterial species in biogas slurry were Sterolibacterium and Clostridium. Notably, the abundance of Clostridium in biogas slurry increased following long-term amendments, while other species such as GP1 and Subdivision3_genera_incertae_sedis decreased; which was consistent with the results of module-eigengene analysis. Long-term organic pulses shifted the balance of microbial community assembly from stochastic to deterministic processes. Overall, our findings indicated that organic pulses accompanied with bacterial invasion could be alleviated by the resilience of soil microbial communities, thereby emphasizing the importance of microbiota assemblage and network architecture. [Display omitted] • Biogas slurry increased rice yields, but also induced microbial disturbance. • Soil resident communities exhibit resilience rather than resistance to long-term biogas slurry pulse. • Long-term organic pulses facilitated deterministic processes in the resident community. • Clostridium , a biomarker species in biogas slurry, increased with the amendment time. [ABSTRACT FROM AUTHOR]

Plantation crops are likely to be highly vulnerable to climate change because of their long economic life span, their typically non-irrigated cropping pattern and the inability to easily switch crops due to high upfront capital costs. Hence the sector requires appropriately designed adaptation options to cope with on-going climate change. Studies on climate adaptation in perennial cropping systems are rare relative to those on annual crops. Based on a cross-sectional survey of 50 tea estate managers representing all tea growing areas in Sri Lanka, this study analyses factors affecting choice of preferred adaptation options, barriers to adaptation and associated policy implications for tea production as an example of a perennial tree crop system. Current adaptation options identified are crop diversification, soil conservation, and shade tree establishment and management. All of these options are adopted in some situations and locations. All estate managers interviewed believe that climate change is happening and almost all are experiencing the negative impacts of climate change on tea production. Results from a multinomial logit analysis show that information on climate change, company size, tea growing elevation, and increases in temperature and rainfall are key factors influencing the preferred choice of adaptation option. Furthermore, results reveal that barriers such as a lack capital, inadequate access to near-term and medium-term climate knowledge, and poor governmental and institutional support may prevent estate managers from experimenting with new adaptation options. Policies should, therefore, be aimed at promoting new adaptation options through information exchange between a wide range of stakeholders, and integrating climate change adaptation with Sri Lanka’s sustainable developmental goals. Governmental and institutional support and involvement would be instrumental in facilitating adoption of adaptation options such as joint-production of tea with valuable timber crops. [ABSTRACT FROM AUTHOR]

Purple sweet potato is one of the main food crops in the tropical and subtropical areas. Purple sweet potato is abundant in anthocyanins, starches, non-starch polysaccharides, caffeoylquinic acid derivatives, vitamins and minerals. Among these components, anthocyanins have been considered as the major biological molecule and are responsible for deep purple color in purple sweet potato. The main chemical structure of purple sweet potato anthocyanins (PSPAs) includes cyanidins and peonidins in the form of monoacylation and diacylation. Owing to heat resistance and ultraviolet stability, PSPAs possess potential applications in the fields of food, cosmetics and pharmaceuticals. Moreover, PSPAs have attracted increasing attention due to their antioxidant, anti-inflammatory, anti-cancer, hypouricemic, hepatoprotective, hypolipidemic, hypoglycemic and neuroprotective activities. This review summarizes recent advances on the health-promoting activities of PSPAs, which will provide a theoretical basis of PSPAs for the development of functional foods. Purple sweet potato anthocyanins have antioxidant, anti-inflammatory, anti-cancer, hypouricemic, hepatoprotective, hypolipidemic, hypoglycemic and neuroprotective activities. [Display omitted] • Purple sweet potato is a highly nutritional food crop. • Purple sweet potato is rich in anthocyanins. • Purple sweet potato anthocyanins exhibit heat resistance and ultraviolet stability. • Purple sweet potato anthocyanins have numerous health-promoting activities. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Macauba palm (Acrocomia aculeata (Jacq.) Lodd. ex Mart. Arecaceae) is a novel oil crop with wide industrial applicability. However, little is known about the photosynthetic responses to seasonality during fruit development in macauba palm and its effects on the fatty acid profile of mesocarp oil and its physicochemical and spectroscopic characteristics. The fatty acid profile changed in six fruit developmental stages (ranging from 180 days after anthesis to full ripening and dispersion). This occurred during the transition from dry to rainy season concomitant with adjustments in photosynthetic responses. The increase in mesocarp oil yield in the fruit was synchronized with the higher photosynthetic capacity at the beginning of the rainy season, being characterized by a raise in oleic acid. The dynamics of soluble solids, acidity, pH, total sugars and starch were proportional to the spectroscopic changes and allowed to determine the ideal harvest point: 360 days after anthesis, with fruits still in the bunch. The macauba palm fruits in this stage showed suitable physical and chemical characteristics for industrial use, as well as higher oil yield. The monitoring of chemical changes with Fournier transformed infrared spectroscopy techniques would aid fast and precise detection of the fruit development and its ideal harvest point. • Macauba is an emerging tropical crop with potential use in biodiesel production. • Seasonal photosynthetic adjustments are synchronized with fruit development. • Environmental factors during fruit development affect the mesocarp oil concentration. • Final ripening stage can be monitored by physicochemical or spectroscopic techniques. • Fruits for oil production can be collected in the bunch, 360 days after anthesis. [ABSTRACT FROM AUTHOR]

Moringa oleifera is one of the most widely cultivated crops in tropical and sub-tropical areas in the world. The common name is drumstick whichcontains 6 to10 seeds. The matured seeds yield 38 - 40% of colourless and odorless vegetable oil. The oil contains concentrated oleic acid which has the potential to be usedas a biodiesel. Thestudy reviewed the prospect of moringaoleifera seed oil as a source of alternative transport fuel in Australia. The distributions, habitat, growth, production, oil extraction and biodiesel conversion techniquesare briefly discussed. The literatures available on engine performance test and emission studies are also summarized for better understanding of the prospect of the moringaoleifera as a sustainable and alternative source of transport fuel. A review of the literatures indicates that moringaoleifera oil could be one of the prospective sources of biodiesel in Australia. Further studies are recommended on issues such asengine combustion characteristics, emission parameters, environmental impact and economic analysis of the species before it can be considered for commercial application. [ABSTRACT FROM AUTHOR]

To evaluate the effect of farming system on gaseous emission of N from soil, the measurements of nitrous oxide (N2O) were taken in organic and conventional paddy fields in tropics. Eleven soil samples from organic and neighboring conventional sites in Central Java, Indonesia were incubated at two different moisture contents expressed as water filled pores (WFPS), namely 75% WFPS and 100% WFPS. Emission of N2O-N at 75% WFPS was significantly higher in conventional management than in organic management. At 100% WFPS, the N2O-N emission was also higher in conventional than in organic farming system. Although it was not significantly different, it has significantly and positively correlations with SOC, total N and initial mineral N content. Due to the swelling ability of the high clay which is contained in soil samples, less N2O-N emission in 75% WFPS than in 100% WFPS was observed in the present study. The range of N2O-N emission at 75% WFPS was 0.01 – 0.03 kg N2O-N/ha in organic farming and 0.005 – 0.16 kg N2O-N/ha in conventional farming; for organic farming at 100% WFPS, the N2O-N emission was 0.04 – 61 kg N2O-N/ha and in conventional farming was 0.08 – 74 kg N2O-N/ha. This study concludes that organic farming in paddy fields might have more promising potential to mitigate N2O-N emission than conventional farming in paddy fields. [ABSTRACT FROM AUTHOR]

Abstract: A total of 638 isolates of rice blast (Magnaporthe oryzae) were isolated in 2002–2009 from different rice varieties in different regions of Sichuan, China and inoculated onto seven rice varieties (Lijiangxintuanheigu, IR24, Minghui 63, Duohui 1, Chenghui 448, Neihui 99-14 and RHR-1) to differentiate the virulence types of the fungus and trace the changes. The virulence to the seven varieties was respectively scored at 1, 2, 4, 8, 16, 32 and 64. The total scores of individual M. grisea isolates which were the sum of scores infecting differential varieties could, in turn, be used for the nomenclature of the virulence types due to their accordance to the special virulence patterns. The 638 tested isolates were then differentiated into 56 different virulence types. Type 15 virulent to Lijiangxintuanheigu, IR24 and Minghui 63, and Type 127 virulent to all of the seven varieties were the most dominant virulence types respectively with the occurrence frequencies of 15.99% and 15.83%. Type 19 and other seven virulence types were not monitored during 2002–2009. Type 15 was the predominant virulence type in 2002, 2003, 2004 and 2007, whereas Type 127 had been the most dominant virulence type after 2005 except for the year 2007 when the province underwent severe drought. Five hundred and seven out of the 638 tested isolates were virulent to Minghui 63, and 89.58% of the 384 isolates virulent to either Duohui 1, Chenghui 448 or Neihui 99-14 were virulent to Minghui 63, which indicated the impact of the extensive plantation of hybrid rice Minghui 63 as the restorer line on the virulence evolution of M. oryzae in Sichuan. The virulence pattern of the dominant virulence types suggested that the acquiring of virulence to all the major resistant restorer lines was the main routes of the evolution in virulence of M. oryzae to hybrid rice in Sichuan. The virulence frequencies of the 638 tested isolates to IR24, Minghui 63, Duohui 1, Chenghui 448, Neihui 99-14 and RHR-1 were respectively 74.6%, 79.5%, 73.8%, 37.0%, 39.0% and 40.4%. The analysis for the sources of the different virulence type isolates indicated the pathogen on the newly released resistant varieties were stronger than conventional rice varieties which had become susceptible in the field since 1980s. [Copyright &y& Elsevier]

Abstract: Investigation of genetic diversity and relationships among breeding lines is of great importance to facilitate parent selection in hybrid rice breeding programs. In this study, we characterized 168 hybrid rice parents from International Rice Research Institute with 207 simple sequence repeat (SSR) and 353 single nucleotide polymorphism (SNP) markers. A total of 1 267 SSR and 706 SNP alleles were detected with the averages of 6.1 (SSR) and 2.0 (SNP) alleles per locus respectively across all lines. Based on the genetic distances estimated from the SSR and SNP markers separately and combined, the unrooted neighbor-joining cluster and STRUCTURE analyses consistently separated the 168 hybrid rice parents into two major groups: B-line and R-line, which is consistent with known parent pedigree information. The genetic distance matrices derived from the SSR and SNP genotyping were highly correlated (r = 0.81, P < 0.001), indicating that both of the SSR and SNP markers have distinguishable power to detect polymorphism and are appropriate for genetic diversity analysis among tropical hybrid rice parents. A subset of 60 SSR markers were also chosen by the Core Hunter with 368 alleles, and the cluster analysis based on the total and subset of SSR markers highly corresponded at r = 0.91 (P < 0.001), suggesting that fewer SSR markers can be used to classify and evaluate genetic diversity among parental lines. [Copyright &y& Elsevier]

Copyright of Parcerias Estratégicas is the property of Centro de Gestao e Estudos Estrategicos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Some Eucalyptus species are widely used as a plantation crop in tropical and subtropical regions. One reason for this is the diversity of end uses, but the main reason is the high level of wood production obtained from commercial plantings. With the advancement of biotechnology it will be possible to expand the geographical area in which eucalypts can be used as commercial plantation crops, especially in regions with current climatic restrictions. Despite the popularity of eucalypts and their increasing range, questions still exist, in both traditional planting areas and in the new regions: Can eucalypts invade areas of native vegetation, causing damage to natural ecosystems biodiversity? The objective of this study it was to assess whether eucalypts can invade native vegetation fragments in proximity to commercial stands, and what factors promote this invasive growth. Thus, three experiments were established in forest fragments located in three different regions of Brazil. Each experiment was composed of 40 plots (1m2 each one), 20 plots located at the border between the forest fragment and eucalypts plantation, and 20 plots in the interior of the forest fragments. In each experimental site, the plots were paired by two soil exposure conditions, 10 plots in natural conditions and 10 plots with soil exposure (no plant and no litter). During the rainy season, 2g of eucalypts seeds were sown in each plot, including Eucalyptus grandis or a hybrid of E. urophylla × E. grandis, the most common commercial eucalypt species planted in the three region. At 15, 30, 45, 90, 180, 270 and 360 days after sowing, we assessed the number of seedlings of eucalypts and the number of seedlings of native species resulting from natural regeneration. Fifteen days after sowing, the greatest number of eucalypts seedlings (37m−2) was observed in the plots with lower luminosity and exposed soil. Also, for native species, it was observed that exposed soil improved natural germination reaching the highest number of 163 seedlings per square meter. Site and soil exposure were the factors that have the greatest influence on seed germination of both eucalypt and native species. However, 270 days after sowing, eucalypt seedlings were not observed at any of the three experimental sites. The result shows the inability of eucalypts to adapt to condition outside of their natural range. However, native species demonstrated their strong capacity for natural regeneration in forest fragments under the same conditions where eucalypts were seeded. [Copyright &y& Elsevier]

Abstract: The effects of afforestation on soil carbon (C) stocks are of concern to the plantation carbon budget and the mitigation of global warming. China has the largest tree plantation areas in the world, but the effects of afforestation on soil C are poorly understood. We reviewed Chinese data of soil C, available from 70 publications, to analyze the change of soil C and its affecting factors following afforestation. Our results indicated that afforestation could accumulate soil C in China, with the accumulation rate of 42.05, 30.07 and 73.94gCm−2 yr−1 in 0–20, 20–40 and 0–40cm soil depths. Five years after afforestation, plantations began to accumulate soil C rapidly, and plantations with the age of 10–20 years old had the highest soil C accumulation rate. Afforestation on former cropland and wasteland had higher accumulation rates of soil C than on former grassland. In middle-temperature and warmer regions, the accumulation rate of soil C was higher than that in colder regions, and in semi-humid regions, the accumulation rate of soil C was significantly higher than that in semi-arid regions. Soil C accumulated rapidly in broadleaved and mixed plantations, and the accumulation rate in broadleaved was higher than that in coniferous plantations. Although some uncertainties existed with regard to the data and methods, a reasonable analysis of soil C change following afforestation in China was achieved for the first time. Future studies should be fulfilled with improved sampling and analytical techniques, reliable soil carbon models and synchronous investigation of soil nitrogen dynamics. [ABSTRACT FROM AUTHOR]

The article discusses a study that investigated the effects of present and future climate changes on Irish vegetation. An occurrence of warming was recorded over the last 20 years, with impacts that were influenced by fluctuations in the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. The rise in production of the net ecosystem seen in a grassland and plantation forest indicate an increase in the vegetation greenness during warmer years. Results suggest temperature rises in the country due to greenhouse gases over the 21st century.

Abstract: A time series of leaf area index (LAI) has been developed based on 16-day normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 250m resolution (MOD250_LAI). The MOD250_LAI product uses a physical radiative transfer model which establishes a relationship between LAI, fraction of vegetation cover (FVC) and given patterns of surface reflectance, view-illumination conditions and optical properties of vegetation. In situ measurements of LAI and FVC made at 166 plots using hemispherical photography served for calibration of model parameters and validation of modelling results. Optical properties of vegetation cover, summarized by the light extinction coefficient, were computed at the local (pixel) level based on empirical models between ground-measured tree crown architecture at 85 sampling plots and spectral values in Landsat ETM+ bands. Influence of view-illumination conditions on optical properties of canopy was simulated by a view angle geometry model incorporating the solar zenith angle and the sensor viewing angle. The results revealed high compatibility of the produced MOD250_LAI data set with ground truth information and the 30m resolution Landsat ETM+ LAI estimated using the similar algorithm. The produced MOD250_LAI was also compared with the global MODIS 1000-m LAI product (MOD15A2 LAI). Results show good consistency of the spatial distribution and temporal dynamics between the two LAI products. However, the results also showed that the annual LAI amplitude by the MOD15A2 product is significantly higher than by the MOD250_LAI. This higher amplitude is caused by a considerable underestimation of the tropical rainforest LAI by the MOD15A2 during the seasonal phases of low leaf production. [Copyright &y& Elsevier]

The ILO's Plantations Convention is intended to provide a standard for plantation labour. The Plantations Convention defines plantations - and thus plantation labour - in terms of the production of specific crops in the tropics and subtropics. This paper examines world production of these crops over time to determine the proportions accounted for by labour in countries that have ratified the Plantations Convention. The Convention is shown to have limited reach, with only a minor proportion of plantation crops produced by labour in ratifying countries. The structural conditions under which the Convention's purpose was formulated have altered and the plantation's significance in the global division of labour has diminished. Although the ILO's general approach to agricultural labour is consistent with changes in the sector, the Organisation nevertheless continues to apply its inappropriate definition of plantations in its attempts to extend the reach of the outdated Plantations Convention. The article contributes to an understanding of the complexity of applying labour standards in the parts of global value chains that are located in the global South. It points to the need for revisions to better serve the South's export agricultural workers. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Historia is the property of Universidad de Costa Rica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Field surveys were conducted in northern Ethiopia during the 2004 and 2005 cropping seasons to determine the distribution of chocolate spot (Botrytis fabae) and the association of disease parameters (incidence and severity) with crop management practices. A total of 261 faba bean fields were surveyed in 12 districts and chocolate spot affected all fields. Disease incidence and severity varied among districts and cropping seasons. Significant differences among locations were observed due to altitude, plant density, date of planting, crop growth stage and field management practices. Mean disease incidence of chocolate spot varied from 47 to 100% in most fields while disease severity index ranged from 17 to 49%. The correlation between disease parameters and altitude, field size, plant population and weed density was positive with disease incidence (r =0.565) and severity (r =0.521). Chi-squared analyses of disease incidence and severity revealed a higher frequency (P <0.001) of diseased fields in western than in eastern districts of the northern region. This finding was supported by the high power of prediction (R 2) that was found for the association between districts and the incidence (46%) and severity (45.1%) of chocolate spot disease. High precipitation, high weed density, and early planting also made significant contributions (P <0.01) to chocolate spot epidemics in farmer fields. Western districts of northern Ethiopia, which are more favourable for the development of chocolate spot disease epidemics should be especially targeted for integrated disease management. Our findings indicate that proper weed management and manipulation of planting date are interventions that can reduce the impact of chocolate spot disease in Ethiopia. [Copyright &y& Elsevier]

In Madagascar, rice production is low (2 t ha-1) and does not cover the needs of the population. To satisfy the food requirements, there is a need to develop agriculture on highland areas called "tanety". Soils of tanety have low nutrients availability, particularly phosphorus which is the main plant growth limiting factor (soil solution < 0.1 mg P l-1). Arbuscular mycorrhizal (AM) symbiosis is widely recognized to have high significance for tropical agriculture, particularly for plant P nutrition. The mycorrhizal status of some wild and cultivated plants was determined. Roots were sampled in two locations: the highlands and in the cliff-east. AM development (internal vesicles and hyphae) was estimated by microscopic examination. For the first time several native plants from Madagascar were reported as forming arbuscular mycorrhizae. Crop plants from the highlands were less colonized by AM fungi than wild species, whereas cultivated and wild plants from fallows areas were highly colonized by AM fungi. In highlands, for a long time, dry plants were burnt in furrows to release mineral nutrients. This practice is suspected to have decreased AM fungi population. Four AM fungi were isolated from colonized roots. Two of them were identified as G. fasciculatum. They were successfully propagated on leek growing on red pouzzolane. The efficiency of these isolates was tested in comparison with a strain of Glomus intraradices and found to be more efficient. [ABSTRACT FROM AUTHOR]

The article focuses on the study on the decline of economic importance of agricultural crop pollinators for ecosystem services. The author stressed the importance of considering environmental factors in using pollinator services as economic incentives for conservation. Three cases have also been explored involving the significance of pollination levels for gathered fruits of tropical crops namely Brazil's passion fruits, Ecuador's coffee and Indonesia's cacao. Results indicated that economic benefits from pollinators should include possible ecosystem processes cornering on the plant quality and pollination.

The article presents a reprint of the article "Irish Landlords and Irish Potatoes," by Harriet Martineau, which appeared in the previous issue of "Daily News." It discusses the issue regarding the discrepancy between the various accounts of the state of the potato-crop which is attacked by a crop disease in Ireland. It also features the region of landlord-hating especially on the part of middle class which has something to do with potatoe failure.

The Xishuangbanna Prefecture (21°09′–22°36′ N; 99°58′–101°50′ E) in southern Yunnan is one of the major growing areas for tropical crops in China. Daffy temperature in Winter is about 8°C lower that in Summer. The effects of season on photosynthesis and antioxidant enzyme activities were studied in the tropical fruit tree species Artocarpus altilis (breadfruit), A. heterophyllus (jackfruit) and Garcinia mangostana (mangosteen), growing in an open site. In August 2002 and January 2003, maximum net CO2 assimilation was 17.1 ± 0.3 μmoles m-2 s-1 (mean ± SE) and 10.7 ± 0.5 in breadfruit; 11.7 ± 0.2 μmoles m-2 s-1 and 10.9 ± 0.6 in jackfruit; and 8.6 ± 0.1 μmoles m-2 s-1 and 6.3 ′ 0.4 in mangosteen, respectively. Concentrations of chlorophyll were lower in mangosteen and breadfruit in January than in August, while in January, photo-inhibition was evident in mangosteen and breadfruit by changes in leaf chlorophyll fluorescence. Concentrations of malondialdehyde (a product of membrane lipid peroxidation), carotenoid to chlorophyll ratios, and the activities of the antioxidant enzymes superoxide dismutase, catalase and peroxidase were higher in January than in August, in all species, especially the antioxidant enzyme activities in jackfruit. Moreover, in both August and January, mangosteen suffered severe mid-day photo-inhibition. These results indicate that jackfruit is chilling tolerant, breadfruit is chilling sensitive, and mangosteen is chilling and high-fight intensity sensitive. Breadfruit and mangosteen do not appear to be suitable crops to grow outdoors in southern Yunnan, China. [ABSTRACT FROM AUTHOR]

Dynamics of forest floor organic matter and litterfall were studied for three years in Luchu pine (Pinus luchuensis Mayr.) plantations with and without broad-leaved tree species generated naturally in the northern part of Okinawa Island. The mixed stand was dominated by Luchu pine and Schima wallichii Korthals. Annual fine litterfall for the mixed stand averaged 11 Mg ha−1 yr−1 compared with 8 Mg ha−1 yr−1 for the pure pine stand. The present study revealed that there was a strong relationship between the mean litterfall per individual and the mean basal area per individual for dominant and sub-dominant species (r=0.94; p=0.017). Typhoons have a large influence on litterfall. The mean amount of premature litter were 1.8 and 1.5 Mg ha−1 yr−1 or 17 and 19% of the annual litterfall mass for the mixed and the pure pine stands, respectively. The mean forest floor mass (of material ≤2.0 cm in diameter) was 22% greater in the pure pine stand compared with the mixed stand. A mass balance approach for fine litter decomposition revealed that the residence times of forest floor organic matter were 6 and 8 years for the mixed and pure pine stands, respectively. [Copyright &y& Elsevier]

To determine the effects of intensive cropping of tropical lowland rice (Oryza sativa L.) and the associated long‐term soil submergence on chemical properties of soil organic matter, we used solid‐state 13C and 15N and solution 31P nuclear magnetic resonance (NMR) spectroscopy to analyze the labile mobile humic acid (MHA) and the more recalcitrant calcium humate (CaHA) fractions extracted from a series of soils supporting several long‐term field experiments in the Philippines. The soils varied mainly in degree of submergence and cropping intensity, ranging from a rainfed rice field without soil submergence to irrigated double‐ and triple‐cropped fields in which soil remains submerged almost all year long. As reported previously, all analyses associated increasing intensity of rice cropping with larger proportions of less humified material in the MHA and CaHA, such as diester phosphorus (P), amide nitrogen (N), and phenolic carbon (C). We established significant correlations between proportions of various spectral areas as well as between some spectral areas and other humic acid (HA) properties such as visible light absorption and free radical concentration (positive indices of humification) and hydrogen (H) concentration (negative index of humification). For example, spectral proportions of heterocyclic N were positively, and proportions of amide N and phenolic C negatively, correlated with visible light absorption and free radical concentration, and each of these spectral proportions had an opposite sign when correlated with H concentration. The correlations of N‐alkyl C proportions were the strongest with these properties and with other functional group proportions. [ABSTRACT FROM AUTHOR]

A monitoring network was established in streams within a catchment near the Costa Rican Pacific coast (2008–2011) to estimate the impact of pesticides in surface water (84 samples) and sediments (84 samples) in areas under the influence of melon and watermelon production. A total of 66 (water) and 47 (sediment) pesticides were analyzed, and an environmental risk assessment (ERA) was performed for four taxa (algae, Daphnia magna , fish and Chironomus riparius). One fungicide and seven insecticides were detected in water and/or sediment; the fungicide azoxystrobin (water) and the insecticide cypermethrin (sediments) were the most frequently detected pesticides. The insecticides endosulfan (5.76 μg/L) and cypermethrin (301 μg/kg) presented the highest concentrations in water and sediment, respectively. The ERA revealed acute risk in half of the sampling points of the melon-influenced area and in every sampling point from the watermelon-influenced area. Safety levels were exceeded within and around the crop fields, suggesting that agrochemical contamination was distributed along the catchment, with potential influence of nearby crops. Acute risk was caused by the insecticides chlorpyrifos, cypermethrin and endosulfan to D. magna , fish and C. riparius ; the latter was the organism with the overall highest/continuous risk. High chronic risk was determined in all but one sampling point, and revealed a higher number of pesticides of concern. Cypermethrin was the only pesticide to pose chronic risk for all benchmark organisms. The results provide new information on the risk that tropical crops pose to aquatic ecosystems, and highlight the importance of including the analysis of sediment concentrations and chronic exposure in ERA. [Display omitted] • Pesticide levels and risk were assessed near a tropical watermelon/melon crop area. • One fungicide and seven insecticides were detected in water/sediment samples. • Risk was detected in six (acute) and eight (chronic) out of nine sampling sites. • The sediment dwelling larvae Chironomus riparius showed the overall highest risk. • Sediment monitoring and chronic risk complement traditional acute risk assessment. Acute and chronic environmental risk mainly due to chlorpyrifos, cypermethrin and/or endosulfan was determined in tropical crop areas of melon and watermelon production. [ABSTRACT FROM AUTHOR]