Vasarinių rapsų brendimo dinamikos ir sėklų natūralaus išbyrėjimo tyrimai
| Date |
|---|
2005 |
1997–1999 ir 2001 m. LÞÛU Bandymø stotyje tirta áprastiniø ir hibridiniø vasariniø rapsø (Brassica napus L. ssp. oleifera annua Metzg.) brendimo, sëklø natûralaus iðbyrëjimo bei jø kokybës kitimas derliaus nuëmimo pradþiai bei trukmei pagrásti. Vasariniø rapsø biometriniø rodikliø analize nustatyta, kad áprastiniø veisliø rapsus galima pjauti paliekant 0,3 m, o hibridiniø (‘Terra’) – 0,5 m aukðèio raþienà. Tarp áprastiniø rapsø derlingiausi buvo ‘Sponsor’ (2,98 t ha–1), o hibridiniø – ‘Terra’ (3,35 t ha–1) veislës rapsai. ‘Lisora’ veislës rapsø 1000 sëklø masë buvo didþiausia (3,58 g). Rapsø brendimo dinamikos tyrimais nustatyta, kad esant palankioms meteorologinëms sàlygoms vasarinius rapsus galima pradëti pjauti tiesiogiai kombainais, kai sëklø drëgnis yra maþesnis kaip 15%. Esant nepalankioms sàlygoms, rapsai pjaunami, kai sëklø drëgnis maþesnis kaip 20%. Rapsø nuëmimo trukmæ sàlygoja natûralûs sëklø byrëjimo nuostoliai, kuriø leistinoji riba vienas procentas derliaus. ‘Lisora’, ‘Marinka’ pribrendæ rapsai turi bûti nupjauti per dvi dienas, nes esant lietingiems orams, kasdien iðbyra apie 0,7% derliaus. ‘Sponsor’ ir ‘Terra’ rapsø pjûtis gali tæstis apie 6 dienas, nes kasdien iðbyra atitinkamai apie 0,07 ir 0,05% derliaus. Sëklø kokybës kitimo tyrimais nustatyta, kad suvëlinus áprastiniø veisliø vasariniø rapsø nuëmimà, sëklø riebalingumas sumaþëjo 3%, gliukozinolatø kiekis padidëjo 4%, o hibridiniø ‘Terra’ rapsø riebalingumas sumaþëjo 0,6%.
In the period 1997–1999 and 2001, at the Experimental Station of the Lithuanian University of Agriculture the ripening dynamics, natural seed falling from pods and the dynamics of seed quality variation of common and hybrid spring rape (Brassica napus L. ssp. oleifera annua Metzg.) varieties were investigated. These parameters determine the beginning and duration of rape harvesting. Analysis of the biometrical indexes allowed to state that while harvesting common rape varieties the stubble should be left 0.3 m and while harvesting hybrid rape varieties (‘Terra’) 0.5 m high. The yield of seeds was highest for the common rape variety ‘Sponsor’ (2.98 t ha–1) and hybrid rape variety ‘Terra’ (3.35 t ha–1). The biggest mass of 1000 seeds was shown by the rape variety ‘Lisora’ (3.58 g). Data on the rape ripening dynamics show that under favourable meteorological conditions direct rape harvesting with a combine should be started when the humidity of seeds is less than 15%. Under unfavourable meteorological conditions rape harvesting should be started when the humidity of seeds is less than 20%. The duration of rape harvesting is influenced by natural losses of seed falling, its permissible limit being 1%. The harvesting duration of the rape varieties ‘Lisora’ and ‘Marinka’ should be 2 days, because the wet daily losses of seeds are 0.7%. The duration of harvesting of the rape varieties ‘Sponsor’ and ‘Terra’ is 6 days. Daily seed loss in the rape variety ‘Sponsor’ are 0.07% and ‘Terra’ 0.05%.