*Naeem Sarwar1, Atique-ur-Rehman1, Omer Farooq1, Allah Wasaya2, 1Suhail Saliq and 3Khuram Mubeen
1Department of Agronomy, Bahauddin Zakariya University Multan 6000, Pakistan; *Corresponding E-mail: email@example.com
2College of Agriculture, Bahauddin Zakariya University, Bahadur Sub-Campus Layyah, Pakistan
3Department of Agronomy, MNS-UAM, Multan, Pakistan
High temperature especially at flowering stage is major yield limiting factor as a result of global warming. Rice plants are most sensitive to high temperature at reproductive stage which significantly enhances the pollen sterility. Reproductive stage demand optimum level of phytohormones like auxin and other energy producing compound. We assume that application of naphthalene acetic acid (NAA) may improve the auxin level in heat stressed plants which may improve the pollen viability and crop yield. Pot experiment was conducted to examine the application different concentrations of NAA (0, 10, 20, 30, 50 μmol L-1) on rice crop grown under natural and heat stressed environment at flowering stage. NAA was applied immediately after flowering and then subjected to heat stress later on for few hours. It was found that heat stress at flowering stage significantly reduced the rice crop yield and quality but exogenous application of Naphthalene acetic acid (NAA) improved the crop tolerance to heat stress which leads toward better crop productivity.