RESULTS AND DISCUSSION
1. Stem number mean per plant. Statistical analysis showed that the combined effect of green manures and nitrogen and
their interaction on the number of stems per plant was significant at the 1% level ( Table 1). In the comparison of
interaction effects, clover green manure with 100 % of recommended nitrogen per plant by 21.8 % and among other
treatments that they had significant difference with the control, vetch with 100 % of nitrogen, clover with 75 % of
nitrogen, canola with 100% of N and vetch with 75 % of recommended nitrogen had the most effect on increasing
the number of stems per plant, respectively; and they increased stem number per plant between 11.5-17.2 % in
comparison with the control (Fig. 1) . The results show that the use of green manures, especially legumes, and also
recommended nitrogen top levels increased vegetative growth of potato. The legume plants have caused maximum
shoot emergence and growth. The legume green manure plants because nitrogen producing of their roots are caused
growing of potato plants that were after them and thus they increased stem number per tuber that are produced of
potato. Legume green manure plants because nitrogen producing from their roots increased sprouts growth and also
stems number per potato tuber.