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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722

vol. 16, nr. 2 (2002)

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Relation between the bean pod shape factor and the force required for pod opening
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Kuźniar P., Sosnowski S.
Department of Agricultural Mechanization, University of Rzeszów, Ćwiklińskiej 2, 35-601 Rzeszów, Poland

vol. 16 (2002), nr. 2, pp. 129-132
abstract The paper discusses the research on the relationship between the bean pod shape (defined by the shape factor), its moisture content, and the force necessary for opening it. The research was performed on five cultivars of beans grown for dry seeds - at five moisture content levels. For each tested option the width and thickness of 100 pods was measured in a cross section perpendicular to the main axis of the fruit, passing through its middle part. The shape factor was determined as the ratio of pod width to thickness. As a result of the research, an increase in the shape factor and the force needed for pod opening with rising pod moisture content was recorded for all bean cultivars. This means that internal stresses in sclerenchyma, which increase with pod drying, tend to open the pod and increase its convexity. The more convex the pod, the less force is required for its opening.
keywords bean pod, shape factor, susceptibility to cracking