L. ŠPOKAS and D. STEPONAVIČIUS
Aleksandras Stulginskis University, LT-53361 Akademija, Kaunas Distr., Lithuania
ŠPOKAS, L. and D. STEPONAVIČIUS, 2014. Evaluating the effectiveness of pinolene based pod sealant for reducing shattering losses in several cultivars of rape (Brassica napus l.). Bulg. J. Agric. Sci., 20: 310-320
The research was carried out in 2007–2009 at the Experimental Station of the Lithuanian University of Agriculture. The objective of the research – to find out the effect of climatic factors and pinolene based pod sealant on dynamics of seed moisture content and shattering losses in several cultivars of winter rape (Brassica napus L.). The pod sealant sprayed within two weeks prior to rape harvesting was found to have no effect on dynamics of seed moisture content within pods. With progression of pod maturation and reduction in moisture content up to 15–18% inside of them, the pod sealant did not substantially reduce shatter loss either. Meanwhile, controlled plots and plots treated with pod sealant showed no substantial difference in total shatter losses. Under weather conditions favourable for maturation of winter rape pods, after seed moisture content achieved 8–12%, pod sealant was found to substantially reduce shatter loss. In case of delayed rape harvesting, shatter loss increased substantially more rapidly in the cultivar non-treated with pod sealant when compared to the treated one. The action of pod sealant is also influenced by the properties characteristic to rape varieties. Moreover, abundant precipitation and strong winds (exceeding 12 m s-1) increase shattering losses by approximately 15 kg ha-1 per day. In Lithuania, harvesting of winter rape should be started at their seed moisture content below 15%. Under favourable weather conditions, rape harvesting should take no more than five days. Under production conditions, using grain combine harvesters to directly harvest matured spring rape, the effect of pod-sealant on shatter loss from harvesting was not substantial.