Assessing genetic diversity and identifying trait-specific germplasm within germplasm collections is necessary for a varietal development programme. Agronomic features were investigated in 318 diverse dry bean germplasm accessions, including check varieties. We observed a lot of genetic variability for the traits studied. A wide range of variations was noticed for days to 50% flowering, days to maturity, pod length, the number of seeds per pod and 100-seed weight (HSW). For eight of the agronomic features evaluated, the analysis of variance revealed substantial differences among the accessions. For all characters, phenotypic coefficient of variation estimations were more significant than genotypic coefficient of variation. Plant height, days to 50% flowering, seed yield (q/ha) and HSW had high heritability and genetic advance as a per cent of the mean. Association analysis revealed a significant positive relationship between HSW, plant height, pod length and seed yield (q/ha). According to a hierarchical clustering analysis based on agronomic features, the diversity of dry bean germplasm has no significant association with their geographical origin. The number of pods per plant, plant height, days to maturity, days to 50% flowering and seed yield had relatively long vectors based on principal components 1 and 2, indicating that genotypes differ significantly. Additionally, the trait-specific donors and bean common mosaic virus disease-resistant accessions, IC360831, ET4515, EC150250, IC340947, IC564797B, EC565693 and ET8409 could be of value for dry bean improvement.

Screening for an early detection of disease, particularly when the screening tests have to be carried out on a number of occasions during the lifetime of a person, is a complex issue and the development of suitable models that can help in setting up good screening programmes for a community is a challenging task. In most cases the current emphasis is on screening at regular intervals of time and the frequency of screening is determined, usually in an informal way, by factors like the nature of the test and the nature of the disease. Analysis of a simple two-state model leads to a basic building-block which can be used in the construction of models for a variety of screening programmes. The use of this building block is illustrated and it is shown that the determination of non-regular screening times in a formal manner can lead to a greater efficiency.