Author(s): Alam Sher, Aaqil Khan, Li Jin Cai, Mhummad Irfan Ahmad, Umair Asharf and Sikander Ali Jamoro
Modern cropping is based on relatively high plant density. The improved grain yield per unit area of modern maize (Zea mays L.) hybrids is due to the increased optimum plant population rather than the improved grain yield per plant. High plant density has been widely used to enhance grain yield in maize. Subsequently we review the effect of planting density on physiology, phenology, morphology, nitrogen use efficiency, water use efficiency grain yield information in maize crop. At higher plant populations reduced grain yield also results from the increased pollento- silking interval and the following barrenness. However, it may lead to higher risk lodging hence causing significant yield loss of the crop. Future insights are morphological and physiological basis controlling barren and stalk lodging resistance. How root traits, and anatomy of sheath and stem of maize plants correspond to high plant population and a further study on the physiological and biological basis of organ development that may govern the mechanisms of high plant density would be essential for future research.
