Combatting Cocoa Swollen Shoot Virus Disease: What do we know?

Cocoa Swollen Shoot Virus Disease (CSSVD) is one of the major factors limiting cocoa (Theobroma cacao L.) productivity in West Africa. The only cure for CSSVD is to cut out visibly infected trees and the official eradication campaign in Ghana has cut out more than 200 million trees since 1946. 80 years of research on preventive control measures have mainly focused on resistance breeding, mild strain cross-protection (inoculation of cocoa seedlings with a mild strain of the virus to protect against the severe strain) and control of mealybug vectors. Meanwhile, diversification measures such as agroforestry (for shading) or barrier (strip) cropping have received less attention. Despite promising results, CSSVD is more prevalent in the field than ever before. The large body of knowledge on preventive control measures for CSSVD is fragmented and many publications are not easily accessible. Furthermore, the literature has never been systematically evaluated and quantitatively assessed. Hence, we consolidated this knowledge with an extensive literature review followed by meta-analysis to identify the pertinent research gaps. Out of 423 publications on CSSVD-related issues, we selected 34 studies, which contained 52 datasets on seven different preventive control measures. Results showed that resistance breeding and mild strain crossprotection may reduce CSSVD infection by 30 percent, while the potential of diversification measures (shading/agroforestry and barrier (strip) cropping) seems to be considerably higher (40 and 85 percent, respectively). However, there is a lack of evidence because of a low number of studies about diversification measures, indicating that our results have to be interpreted with care and calling for more research in this area. Future testing is needed to evaluate the efficacy of barrier (strip) cropping to reduce CSSVD, and address the effect of shade on CSSVD symptom severity. Furthermore, the practical relevance of different preventive control measures for farmers needs to be assessed, and shade should be considered in current breeding programs for CSSVD resistance

Лазерное зондирование и многофакторное статистическое моделирование оптико-физических свойств неизотермических закрученных турбулентных газовых потоков

Currently, the only effective treatment for cocoa (Theobroma cacao L.) infected with the cocoa swollen shoot virus disease (CSSVD) is to cut and replant infected trees. Hence, the development of preventive control measures and strategies to mitigate the severity of the disease are of utmost importance. While past research has mainly focused on resistance breeding, mild strain cross protection and vector control, diversification measures such as agroforestry have received relatively less attention, despite their potential to mitigate CSSVD severity. Therefore, we studied the effects of shade on CSSVD symptom severity, capsid damage and cocoa yield along a gradient of increasing shade tree abundance in smallholder cocoa farms in Ghana. Furthermore, we measured photosynthetic active radiation and assessed soil fertility in order to elaborate on potential causal factors for possible shade effects on CSSVD symptom severity. Both CSSVD symptom severity and cocoa yields followed quadratic curves, and were found to be lowest and highest in plots with 54% and 39% shade, respectively. The simulated optimal shade levels for CSSVD symptom severity and cocoa yield overlapped between 45%-53%, indicating that agroforestry systems with around 50% shade cover may be an optimal coping strategy to balance CSSVD symptom severity versus reduced cocoa yield until diseased cocoa is replaced with more resistant varieties. Furthermore, our results suggest that rather than soil fertility, high-light and possibly also soil moisture stress may have been responsible for the shade effects on CSSVD symptom severity

Social network to inform and prevent the spread of cocoa swollen shoot virus disease in Ghana

The cocoa swollen shoot virus disease is a major factor limiting cocoa (Theobroma cacao L.) productivity for West African farmers. The only treatment against this disease is to cut infected trees and replant with disease-free planting material. Research has recommended the prevention measures: (i) cordon sanitaire (leaving 10-m-wide cocoa-free zone around cocoa), (ii) barrier cropping, (iii) using partly tolerant hybrids, and (iv) removing specific alternative host tree species. Here, we evaluate the current adoption of these measures and identify their adoption constraints. We conducted a quantitative survey with 396 farmers in the Eastern and Western Regions of Ghana, held six focus group discussions and hosted a multi-stakeholder validation workshop with 31 key actors in the cocoa value chain. Our results indicate that the adoption of prevention measure against the disease remains limited. Farmers with a more extensive social network (number of family members/close friends who already adopted a particular measure), a larger farm size, more secure land tenure rights, and more knowledge about the measures were more likely to adopt them, especially barrier cropping, hybrid seedlings, and removing alternative host trees. Lack of knowledge about the measures was the single biggest barrier for their adoption, with 51% of the participating farmers not even being aware of any prevention measures. Here, we show for the first time that the social network is the main information source for farmers, which agrees with the finding that the flow of information between farmers and other stakeholders is a critical factor affecting knowledge spread and consequently adoption. Our results provide crucial insights for the elaboration of an implementation action plan to boost the dissemination of feasible prevention measures against the cocoa swollen shoot virus disease in Ghana in order to efficiently cover farmers’ needs for information (technical advice) and inputs (access to hybrid seedlings).ISSN:1774-0746ISSN:1773-015

Записки о социологическом осмыслении настоящего глобального экономического кризиса

The approaches to obtain the prior goal of staving off the financial crisis and economic depression are considered in the context of a modern global economic crisis. Learning the contradictions and consequences of the present crisis means analyzing the contradictions of a modern society. Five constructively interconnected distinctions reflecting the specificity of its sociological aspect are suggested. = В контексте современного глобального экономического кризиса анализируются подходы к решению приоритетной задачи по предотвращению финансового краха и экономической депрессии. Изучение противоречий и последствий настоящего кризиса предполагает анализ противоречий современного общества. Приводится пять конструктивно взаимосвязанных признаков, отражающих специфику его социологического аспекта