Czynniki ksztaltujace wlasciwosci agrofizyczne rzepaku

Learning and descrybing the mechanical properties changes of siliques and stalks as well as chemical ones of rape seeds during their development, in terms of technological processes optimization, allow to minimize the qualitative and qualitative losses of seeds at the latest stage of rape maturation and during harvest. One of the basic rape property that often determines its profitability is silique compliance to cracking and seed shedding. Investigations made showed that the newest varieties need to fulfill the strict technological requirements, among others: estimation of a proper maturity stage, compliance with harvest terms, application of proper maturation regulators at proper moments, choosing of suitable harvest technology in relation to plantation state. These factors significantly modify not only silique susceptibility to cracking and seed shedding but also seed technological valuc judged as quality of oil obtained. In this paper we studied the changes (silique compliance to cracking and quality of seeds harvested) thai were invoked by chemical compounds (development and maturation regulators) depending on a dose, application term and the weather conditions. All above realizes the possibilities that may be used to adapt artificially the biological and mechanical rape properties to machines and technology requirements. The method and machinery worked out in IA PAN enable to precise the parameters describing the siliques compliance and their mechanical characteristics elaborated for many years (using tens of varieties) should be taken into account during breeding works on the variety with non-cracking siliques. Describing of siliques using mechanical parameters gives an information to breeders about threats and points to varieties with positive features investigated. Precise characteristics of varieties, in those terms, also enables choosing the best ones for cultivation. Results presented in this paper give a wide range of information on plants properties that directly affect the qualitative and quantitative seed loss amounts including variability due to the maturation, varieties, conopy physical state, unfavorable weather conditions, diseases and pests appearance as well as chemicals application.