Effects during Period of Siliqua Developing of KH2PO4 and MgSO4 Application on Nitrogen Transportation in Pods of Oilseed Rape(Brassica napus L.)

An experiment was conducted in field experiment plot to investigate nitrogen transportation from hulls of pods in different periods at early stage of siliqua developing and effect of KH₂PO₄ and MgSO₄ application on it using ¹⁵N-urea.
More than 80 % of ¹⁵N applied on the surface of pods at lower terminal during flowering was recovered from all pods one month after flowering, most of them were still in the hulls of labelled pods, 17-27 % of ^l5N applied was transported into seeds, a small amount was transported to pods at upper terminal, a little amount was found in pods at branch. More ^l5N applied in middle period of flowering was transported to pods at upper terminal and branch than those applied in early period of flowering. It should be further investigated to conclude how will be going on transportation of nitrogen from hulls as preceding of siliqua developing towards maturity of seeds and its difference between ¹⁵N applied in more different periods.
Application of KH₂PO₄ and MgSO₄ with ¹⁵N-urea of surface of pods promoted transportation of ¹⁵N into seeds from hulls, effect of MgSO₄ was more notable.