Solveig Danielsen

Fungal Endophytes from Stalks of Tropical Maize and Grasses: Isolation, Identification, and Screening for Antagonism against Fusarium verticillioides in Maize Stalks

A bioassay to screen fungal isolates for endophytic growth and antagonism against Fusarium verticillioides in maize was developed. The method was based on the commonly used toothpick inoculation method followed by measurement of stalk necrosis, and was designed to assure a direct introduction of the endophyte into the plant. Thirty-four fungal endophytes isolated from surface sterilized grass and maize stalks from Costa Rica, and four soil isolates, were tested for antagonism and endophytic growth. Six isolates gave less necrosis (P < 0.05) than the control treated with F. verticillioides alone, but only one isolate, Trichoderma koningii S8, reduced the stalk necrosis when the test was repeated. Reisolations from the stalk showed that none of the isolates were able to completely eliminate F. verticillioides from the maize stalk. It is concluded that F. verticillioides is a very strong competitor that is highly adapted to live in association with maize, and that an effective antagonist against F. verticill...

A novel approach to quality assessment of plant health clinics

Since 2003, community-based plant health clinics have been established in several developing countries as a new, low-cost method to provide plant health advice to smallholder farmers who have limited access to advisory services. As the plant clinics are becoming more widespread, there is an increasing need to create basic procedures to regulate clinic operations. This paper describes how the concepts of ‘plant health clinic quality’ evolved from 2006 to 2009 and how a novel framework for quality assessment was developed in Nicaragua, Bangladesh, Vietnam, Bolivia and Uganda. Quality criteria for plant clinics include technical quality, timeliness, staff attitude, feasibility of advice, clinic location, materials, organization and outreach. These criteria show many similarities to those applied successfully in human and animal healthcare. Allowing plant clinic staff and their supervisors to define the quality criteria and monitoring methods themselves has helped raise awareness about clinic performance and improve self-assessment skills. Monitoring visits are being done more consciously and systematically and there are indications that register management and decision-making processes are improving as well as staff motivation. Monitoring protocols and quality assessment are now accepted as an essential component of plant clinic operations to improve clinic performance and accountability to farmers.

Plant health clinics in Bolivia 2000—2009: operations and preliminary results

Smallholder farmers need information on plant diseases. Ten plant health clinics (Postas para Plantas) evolved in Bolivia after 2000 and are still operating due to the efforts of three local institutions. The plant clinics receive any problem, on any crop, and give written and verbal recommendations, immediately if possible. Many clinics are held at weekly farm fairs, where villagers from many surrounding communities can seek help. The clinic staff write fact sheets for farmers on common problems. From 2000 to early 2009 the clinics received more than 9000 queries on over 100 crops with potato comprising two thirds of the queries, followed by peach, tomato and broad bean. Potato tuber moth and potato weevil were by far the most dominant plant health problems in the high Andes, but not in lowland areas. The diversity of crops and problems are a big challenge to the clinic staff. With basic training and practical experience they learn to diagnose most problems. However, they need access to expert support to solve some of the more difficult problems and improve the quality of advice. Preliminary results show cases of poverty alleviation, reduction in pesticide abuse, increased harvests and other benefits. The plant health clinics in Bolivia enabled extension and research to reach more farmers with a timely low-cost service.

Using Plant Clinic Registers to Assess the Quality of Diagnoses and Advice Given to Farmers: A Case Study from Uganda

Abstract Purpose: This study developed a framework for quality assessment of diagnoses and advice given at plant clinics. Design/methodology/approach: Clinic registers from five plant clinics in Uganda (2006–2010) were used to develop quality assessment protocols for diagnoses and advice given by plant doctors. Assessment of quality of diagnoses was based on five validation criteria applied on the ten most common crops. Quality of advice was assessed for the four major problems considering efficacy and feasibility. Findings: The quality of diagnoses varied between crops, from 68% completely validated in maize to 1% in tomato. Complete and partially validated diagnoses were 44% of all queries. The remaining 56% were rejected. Several basic weaknesses were found in data recording and symptom recognition. A greater consistency and precision in naming diseases would increase the number of completely validated diagnoses. The majority of recommendations (82%) were assessed ‘partially effective’. ‘Best practice’ was recommended for 10% and ineffective advice was given in 8% of the cases with considerable variation between diseases. Practical implications: Plant doctors need more training in symptom recognition, pest management and record keeping as well as better technical backstopping to solve unknown problems. Common standards and procedures for clinic data collection and analysis should be established, and roles and responsibilities clearly defined. Originality/value: This is the first time plant clinic registers have been used to systematically assess quality of plant clinic services. Apart from being a valuable tool for quality assessment of extension, the plant clinic registers constitute a novel source of regular information about pests, diseases and farmer demand that can help improve decision-making of extension service providers, researchers, plant health authorities as well as information and technology providers.

Two subpopulations of Colletotrichum acutatum are responsible for anthracnose in strawberry and leatherleaf fern in Costa Rica

Strawberry, Fragaria × ananassa, and leatherleaf fern, Rumohra adiantiformis, are two important crops in Costa Rica. One of the most severe diseases affecting these crops is anthracnose, caused by members of the fungal genus, Colletotrichum (teleomorph; Glomerella). Eighty single-spore isolates from strawberry and leatherleaf fern were identified as Colletotrichum acutatum by species-specific PCR, and were further characterised by Universally Primed PCR (UP-PCR) fingerprinting analysis, and sequence analysis of the ribosomal internal transcribed spacer (ITS) region. Morphological differences, genotypic variation revealed by UP-PCR fingerprinting analysis, and a single sequence polymorphism within the ITS2 region were found between the isolates from strawberry and leatherleaf fern, respectively. The UPGMA cluster analysis of the fingerprints clearly separated the isolates derived from strawberry and leatherleaf fern into two different clusters. Pathogenicity assays on detached strawberry fruits confirmed the apparent difference between the two groups of isolates. It is therefore suggested that the pathogens responsible for strawberry anthracnose fruit rot and leatherleaf fern anthracnose in Costa Rica, belong to two distinct subpopulations of C. acutatum.

Morphological and Molecular Characterization of the Causal Agent of Downy Mildew on Quinoa (Chenopodium quinoa)

Downy mildew is an economically important and widespread disease in quinoa (Chenopodium quinoa) growing areas. Although in many studies Peronospora farinosa is most commonly regarded as the causal agent of the disease, identification and classification of the pathogen remain still uncertain due to its taxonomic confusion. Thirty-six Peronospora isolates from quinoa with different geographic origins including Argentina, Bolivia, Denmark, Ecuador, and Peru were morphologically and molecularly compared with Peronospora species from other Chenopodium species. The morphology of three herbarium specimens was similar to that of P.variabilis, which originated from C. album, characterized by flexuous to curved ultimate branchlets and pedicellated conidia. Phylogenetic analysis based on ITS rDNA sequences also placed the quinoa pathogen within the same clade as P. variabilis. Within the ITS rDNA sequences of the quinoa pathogens, two base substitutions were found, which separated the majority of the Danish isolates from isolates from South America, but no sequence difference was found among the isolates from different cultivars of quinoa. The present results indicate that the pathogen responsible for the quinoa downy mildew is identical to Peronospora variabilis and that it should not be lumped with P. farinosa as claimed previously by most studies.

Using a plant health system framework to assess plant clinic performance in Uganda

Systems thinking is commonly applied to understand the complexities of human healthcare delivery. In contrast, plant health systems as an organising principle have evolved more recently from work with plant clinics as providers of plant healthcare services to farmers. As plant health systems evolve and expand, new analytical frameworks and tools are needed to identify factors influencing performance of services and systems in specific contexts, and to guide interventions. In this paper we apply a plant health system framework to assess plant clinic performance, using Uganda as a case study. A comparative study of plant clinics was carried out between July 2010 and September 2011 in the 12 districts where plant clinics were operating at that time. The framework enabled us to organise multiple issues and identify key features that affected the plant clinics. Clinic performance was, among other factors, influenced by basic operational and financial concerns, inter-institutional relations and public sector policies. Overall, there was a fairly close match between the plant health system attributes and plant clinic performance, suggesting that the framework can help explain system functioning and identify intervention points and domains for strengthening plant health systems. The plant health system framework needs further testing to explore the full scope of the method, including assessing the relative importance and interactions of the system components, and tracking attributions and outcomes over time.

Universally Primed‐PCR indicates geographical variation of Peronospora farinosa ex. Chenopodium quinoa

In the Andean region of South America downy mildew, caused by Peronospora farinosa, is the most important disease of quinoa (Chenopodium quinoa). Peronospora farinosa, a highly polyphyletic species, occurs on quinoa and wild relatives on all continents. However, very little is known about the geographic diversity of the pathogen. As the interest in quinoa as a novel crop is increasing worldwide, geographical differences in the population structure of the downy mildew pathogen must be taken into consideration in order to design appropriate control strategies under a variety of circumstances. As a step towards understanding the geographic diversity of P. farinosa from quinoa, 40 downy mildew isolates from the Andean highlands and Denmark were characterized using universally primed PCR (UP‐PCR). Eight UP‐PCR primers were tested. A combined analysis of markers separated the Danish and Andean isolates in two distinct clusters. This study raises new questions about the origin and spread of P. farinosa on quinoa, its geographic diversity and host specificity. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

“Here we give advice for free”: the functioning of plant clinics in Rwanda

ABSTRACT Although plant clinics are considered an important mechanism in the service delivery to farmers, not much is known about their functioning in the daily reality of plant doctors and farmer-clients. This article reports on an exploratory study describing the functioning of eight plant clinics in Rwanda. Personal and organisational commitment, publicity, and proactive communication with farmers and local leaders are key factors explaining higher attendance of some clinics. Farmer attendance is under-reported by 40–50%. Data management needs improvement to make clinic records reliable tools for decision-makers. This type of assessment can help improve operations and realise the plant clinics’ potential.

Access and coverage: which farmers do plant clinics reach in Uganda?

ABSTRACT This article reports on a study that assessed farmers’ access to, and coverage of, five plant clinics operating from market places in two districts of Uganda. Despite the noticeable geographic and thematic coverage of the services, placing plant clinics at markets did not automatically ensure equitable access and high farmer attendance. Clinic users were predominantly middle-aged male farmers and overall attendance was relatively low. Uganda has taken plant clinics to scale in recent years due to their potential to strengthen the country’s responsiveness to pests and diseases. Optimising farmer reach and ensuring equity in access requires reviewing clinic placement, timing, and mobilisation strategies.