Quantifying leaf development in wheat different cultivars: II- production and senescence of leaves on plant in the field

In order to the study of leaf production and senescence of wheat different cultivars, two Field experiments as a Randomized Complete Block Design using 15 wheat cultivars were conducted at the research farm of the Islamic Azad University of Ramhormoz Branch ((latitude 31.16°N, 49.36°E and 151 m asl) in 2006-7 and 2007-8. Results indicated at first stage of leaf production, to increase one leaf on main stem, 1.32 leaves added to plant leaves. after production of five leaves on main stem and starting of plant tillering (second phase of leaf plant production) to increase one leaf on main stem, almost five leaves added to plant leaves. The study of leaf senescence showed that leaves senescent occurred at two phases like situation of two-phases production of leaf on plant. At first phase, for every increase of one percent in fraction senesced leaves on main stem, fraction of senesced leaves per plant had an increase of 0.71. This increase continued until the fraction of senesced leaves on the main stem reached to 0.28, in other words, when 28 percent of the main stem leaves were senesced. In the second stage, each unit increase in fraction senesced leaves on the main stem was caused a 1.16-unit increase in senesced leaves per plant. Hence, knowing the differences among hybrids in leaf area attributes may be useful in plant breeding, crop management and in simulation models of wheat.