تاثیر تراکم بوته بر تولید و پیر شدن برگ در ساقه اصلی گندم

Plant density is an important management factor on crop yield. In order to quantify the production and aging of leaves in main stalk of wheat experiment was conducted in a randomized complete block design in research farm of Gorgan University of Agricultural Sciences and Natural Resources in 2012-13. Treatments consisted of density (50, 100, 200, 350, 500, 650, 800) and varieties were (Kuhdasht and Morvarid). Distance between rows was 20 cm. In this study 4 replicates were used. The results showed that leaf production stopped after the 1029 heat units and aging of leaves occurred after 1119.5 heat units. Leaf appearance rate was 0.008 leaf on growth degree day therefore amount of Filocrown was 114 growth degree day. Regression for all coefficients of leaf production against plant density was not significant. For Kohdasht variety to yellowing leaf, b (leaf decay rate) and X0 (turning points and start to decaying leaf) was significant at the one percent level and for Morvarid variety X0 (turning points and start to decaying leaf) was significant and b (leaf decay rate) was not significant at the five percent. Results showed production and declining in wheat leaf can be quantitatively expressed in the form of equations.