Pressurized methods for grading the vulnerability of pods splitting
G. Szwed 1
J. Tys 1
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Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, P.O. Box 201, 20-290 Lublin 27, Poland
Acceptance date: 1998-03-05
Int. Agrophys. 1999, 13(3): 391–394
Loss of seeds due to pod splitting at the time of ripening makes it necessary to search for the methods that would allow for the adequate grading of the vu- lnerability of a given variety. These methods should also be convenient instruments in the search for the optimal tech- nology and harvest term. A method of testing air cramming at a suitable pressure for the release of the existing stress perpendicular to the raphe and leading to the pods splitting. The amount of pressure at which the raphes come apart is the measure of its vulnerability to splitting. Studies were carried out on the blue, white and yellow lupines. Diffe- rences in the measured values of the force necessary for the separation of the pod raphe in relation to the species and varieties of the lupines being examined were noted. The differences result from the composition of the raphes, the composition and thickness of the sklerenhym layers such as the geometry of the pod. The series of tests was performed including: the geo- metry of the pods (length, width, thickness, thickness of the walls of the pod), the necessary force for the separation of the pod`s graphe. The strength of the raphe was found in a range from 40.2 to 151.7 G/mm for pods of yellow lupines while in the cause of pods of blue lupines it ranged from 16.5 to 84.0 G/mm. The results for the blue lupines were compared to the field studies on the splitting of pods as well as the shedding of seeds during three successive growing seasons. They showed the significant relations between these features.