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Original issued in series: Bulletin / British Columbia. Horticultural Branch ; no. 68. ; At head of title: Dept. of Agriculture (Horticultural Branch) . ; "Printed by authority of the Legislative Assembly." ; Electronic reproduction. ; Mode of access: Internet. ; 44

In the megapolis, native and adventitious species of woody plants are exposed to the most powerful adverse environmental factors that reduce resistance to diseases and pests. The investigation objective was to identify diseases and pests of a dangerous invasive species Acer negundo L. and to estimate their effect on invasion activity of this species. A. negundo leaves are affected by Рhyllosticta negundinis (Sacc. et Speg.), Sawadaia bicornis (Wallr. ex. Fr.) Miyabe and are occasionally damaged by a timber pest such as Rhopalopus clavipes F. A set of unfavorable environmental factors cause noninfectious toxicosis of A. negundo leaves. Meanwhile, all these diseases and pests do not cause considerable harm to A negundo and do not substantially reduce its invasion activity.

A countrywide survey on cassava constraints in D.R. Congo was initiated in 2002 and completed in 2004 with the aim of assessing the health status of cassava in various agro-ecological zones of the 11 provinces of the country. The survey permitted to update the list of diseases and pests that continue to threaten cassava production in the country. Among the diseases, cassava mosaic virus disease (CMD) was observed to be the most damaging and widely distributed. The incidence was high in all the provinces surveyed averaging 85%. Strains of the viruses responsible of the disease were identified, and included the African Cassava Mosaic Virus (ACMV), and the Uganda variant of East African Cassava Mosaic Virus (EACMV-Ug). Cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) were also observed, however severe incidence and damage were limited to some provinces. The root rot diseases were not frequently observed in the field during the survey. However, a questionnaire was used, farmers in Bandundu, Kivu and Province Orientale complained that root rots were one of the major damaging constraints of cassava, particularly when cassava is harvested late (eg above 18 months after planting). Cassava brown streak virus disease (CBSD) was not observed in much of the areas sampled except in Kinshasa and Bas-Congo provinces where the incidences were rather low. Africa, cassava green mite (CGM) was the most widespread in DRC. However, its incidence and severity were low in the provinces where the exotic natural enemy predatory mite Typhlodromalus aripo had been introduced and is established. Cassava mealybug (CM) was also found in few locations in a limited number of provinces e.g Kinshasa, Bandundu, Kasai Oriental and Kasai Occidental. The low spread and incidence of CM recorded during the survey confirms observations that CM has effectively been controlled by the parasitic wasp Apoanagyrus lopezi De Santis that was released throughout the country in the 1980s. The resurgence of the pest in the few provinces cited above can therefore be attributed to several factors such as the susceptibility of cassava variety (induced by the severe mosaic disease), poor crop management and low soil fertility. Arecently reported pest, the African root and tuber scales (ARTS), whose distribution is limited only to forest zones was observed in Bas-Congo, Province Orientale and Nord-Kivu where the incidence was generally high. Two arthropod species, the Thrips and termites, known in the recent past to be secondary pests of cassava in DRC are now showing high incidence and alarming damages. The whitefly Bemisia tabaci, traditionally known as vector of the virus that cause the cassava mosaic disease (CMD) was observed in very high number inducing honeydew on the cassava leaves. ; United States Agency for International Development ; Peer Review

Preventing disease outbreaks has widespread benefits that are dependent on the actions of many agents but can be undermined by the inaction of others. This paper explores whether a voluntary biosecurity-related assurance scheme can be an effective mechanism for curbing the risks of animal and plant pests and diseases. The decision to engage in such schemes is modelled using a coalition game where agents consider both direct costs of infection and regional outbreak costs like trade bans and movement restrictions. We find that government needs to support the scheme through incentives that reduce members' outbreak costs like pre-agreed outbreak compensation or preferential regulatory treatment. Assurance schemes could provide significant improvements in biosecurity if membership is high; but without government incentives, stable coalitions are either small or ineffective at improving biosecurity. Government support can lead to large coalitions and robust improvement in overall biosecurity, with the optimal level of support being the smallest incentive that leads to a stable grand coalition. Policies that focus on either monetary or non-monetary incentives can lead to more robust improvements in biosecurity. In particular, targeting regional outbreak costs to members like movement restrictions leads to improved biosecurity for all levels of support.

Preventing disease outbreaks has widespread benefits that are dependent on the actions of many agents but can be undermined by the inaction of others. This paper explores whether a voluntary biosecurity-related assurance scheme can be an effective mechanism for curbing the risks of animal and plant pests and diseases. The decision to engage in such schemes is modelled using a coalition game where agents consider both direct costs of infection and regional outbreak costs like trade bans and movement restrictions. We find that government needs to support the scheme through incentives that reduce members' outbreak costs like pre-agreed outbreak compensation or preferential regulatory treatment. Assurance schemes could provide significant improvements in biosecurity if membership is high; but without government incentives, stable coalitions are either small or ineffective at improving biosecurity. Government support can lead to large coalitions and robust improvement in overall biosecurity, with the optimal level of support being the smallest incentive that leads to a stable grand coalition. Policies that focus on either monetary or non-monetary incentives can lead to more robust improvements in biosecurity. In particular, targeting regional outbreak costs to members like movement restrictions leads to improved biosecurity for all levels of support.

The European chestnut population is enduring multiple compounding exotic pest and disease outbreaks across Turkey. The deeply held value of the chestnut species for the Turkish public is reflected in substantial government conservation programming. Chestnut is predominantly found on state land managed by Turkey's General Directorate of Forestry (GDF), which generally upholds restrictive policies for chestnut-related livelihood practices other than nut collection and beehive placement. Such policies are justified by a government position that human activities and presence is likely to worsen disease dynamics. Conversely, a growing body of research findings testify that small-scale livelihood practices maintain biological diversity and, furthermore, that this traditional maintenance of diversity has been correlated with decreased pathogen pressure within agroecosystems. However, few studies have investigated this phenomenon in the context of agroforestry systems. At a global ecological moment of increasingly pervasive and severe exotic forest pathogen impact, this paper investigates the influence of diverse small-scale livelihood practices and knowledge on chestnut tree health across the highly heterogenous geography of Turkey. We conducted ethnobotanical questionnaires with 96 chestnut-utilizing households, and chestnut tree health evaluations in georeferenced forest areas they identified, throughout Turkey's Black Sea, Marmara, and Aegean regions. Using data from 1500 trees, we characterized the effects of subsequently recorded environmental, physiological, and anthropogenic factors on tree health using multiple correspondence analysis (MCA), multiple factor analysis (MFA), and mixed models. Our results show that the traditional human management of tree physiology and ecology has a significant positive effect on tree health, especially through the acts of grafting and culling as well as the maintenance of diversity. We argue that conceptualizing such livelihood systems as human niche construction and maintenance can help forest management agencies to better understand and conserve valuable landscapes, even in increasingly common periods of severe pathogenic pressure. ; Peer Review

The European chestnut population is enduring multiple compounding exotic pest and disease outbreaks across Turkey. The deeply held value of the chestnut species for the Turkish public is reflected in substantial government conservation programming. Chestnut is predominantly found on state land managed by Turkey's General Directorate of Forestry (GDF), which generally upholds restrictive policies for chestnut-related livelihood practices other than nut collection and beehive placement. Such policies are justified by a government position that human activities and presence is likely to worsen disease dynamics. Conversely, a growing body of research findings testify that small-scale livelihood practices maintain biological diversity and, furthermore, that this traditional maintenance of diversity has been correlated with decreased pathogen pressure within agroecosystems. However, few studies have investigated this phenomenon in the context of agroforestry systems. At a global ecological moment of increasingly pervasive and severe exotic forest pathogen impact, this paper investigates the influence of diverse small-scale livelihood practices and knowledge on chestnut tree health across the highly heterogenous geography of Turkey. We conducted ethnobotanical questionnaires with 96 chestnut-utilizing households, and chestnut tree health evaluations in georeferenced forest areas they identified, throughout Turkey's Black Sea, Marmara, and Aegean regions. Using data from 1500 trees, we characterized the effects of subsequently recorded environmental, physiological, and anthropogenic factors on tree health using multiple correspondence analysis (MCA), multiple factor analysis (MFA), and mixed models. Our results show that the traditional human management of tree physiology and ecology has a significant positive effect on tree health, especially through the acts of grafting and culling as well as the maintenance of diversity. We argue that conceptualizing such livelihood systems as human niche construction and maintenance can help forest management agencies to better understand and conserve valuable landscapes, even in increasingly common periods of severe pathogenic pressure.

Kose, Nesibe/0000-0001-5766-0526; ; WOS:000482080800026 ; The European chestnut population is enduring multiple compounding exotic pest and disease outbreaks across Turkey. The deeply held value of the chestnut species for the Turkish public is reflected in substantial government conservation programming. Chestnut is predominantly found on state land managed by Turkey's General Directorate of Forestry (GDF), which generally upholds restrictive policies for chestnut-related livelihood practices other than nut collection and beehive placement. Such policies are justified by a government position that human activities and presence is likely to worsen disease dynamics. Conversely, a growing body of research findings testify that small-scale livelihood practices maintain biological diversity and, furthermore, that this traditional maintenance of diversity has been correlated with decreased pathogen pressure within agroecosystems. However, few studies have investigated this phenomenon in the context of agroforestry systems. At a global ecological moment of increasingly pervasive and severe exotic forest pathogen impact, this paper investigates the influence of diverse small-scale livelihood practices and knowledge on chestnut tree health across the highly heterogenous geography of Turkey. We conducted ethnobotanical questionnaires with 96 chestnut-utilizing households, and chestnut tree health evaluations in georeferenced forest areas they identified, throughout Turkey's Black Sea, Marmara, and Aegean regions. Using data from 1500 trees, we characterized the effects of subsequently recorded environmental, physiological, and anthropogenic factors on tree health using multiple correspondence analysis (MCA), multiple factor analysis (MFA), and mixed models. Our results show that the traditional human management of tree physiology and ecology has a significant positive effect on tree health, especially through the acts of grafting and culling as well as the maintenance of diversity. We argue that conceptualizing such livelihood systems as human niche construction and maintenance can help forest management agencies to better understand and conserve valuable landscapes, even in increasingly common periods of severe pathogenic pressure. ; American Research Institute in Turkey, Philadelphia PA; U.S. Borlaug Fellows in Global Food Security Program, Center for Food Security, Purdue University [8000079396] ; This work was supported by the American Research Institute in Turkey, 3260 South Street, Philadelphia PA 19104, and the U.S. Borlaug Fellows in Global Food Security Program, Center for Food Security, Purdue University (Sponsor Agreement ID 8000079396).

The study examined the contribution of the Cocoa Disease and Pest Control Programme (CODAPEC), which is a cocoa production-enhancing government policy, to reducing poverty and raising the living standards of cocoa farmers in Ghana. One hundred and fifty (150) cocoa farmers were randomly selected from five communities in the Bibiani-Anhwiaso-Bekwai district of the Western Region of Ghana and interviewed using structured questionnaires. Just over half of the farmers (53%) perceived the CODAPEC programme as being effective in controlling pests and diseases, whilst 56.6% felt that their yields and hence livelihoods had improved. In some cases pesticides or fungicides were applied later in the season than recommended and this had a detrimental effect on yields. To determine the level of poverty amongst farmers, annual household consumption expenditure was used as a proxy indicator. The study found that 4.7% of cocoa farmers were extremely poor having a total annual household consumption expenditure of less than GH¢ 623.10 ($310.00) while 8.0% were poor with less than GH¢ 801.62 ($398.81). An amount of money ranging from GH¢ 20.00 ($9.95) to GH¢ 89.04 ($44.29) per annum was needed to lift the 4.7% of cocoa farmers out of extreme poverty, which could be achieved through modest increases in productivity. The study highlighted how agricultural intervention programmes, such as CODAPEC, have the potential to contribute to improved farmer livelihoods.