INVESTIGATION ON THE PHYSICAL PARAMETERS OF ENVIRONMENT AND THEIR IMPACT ON COTTON CROP PRODUCTION IN THE SOUTHERN PUNJAB, PAKISTAN 

Muhammad Iqbal Makhdum, Muhammad Nawaz Malik, Fiaz Ahmad, Fazal Ilahi Chaudhry and Shabab-ud-Din

Central Cotton Research Institute, Multan, Pakistan.

 Abstract: Some physical parameters of the environment and their influence on cotton crop production were studied at Central Cotton Research Institute, Multan (30⁰ 12¢N,71⁰ 28¢ E, alt.123m). The results showed that highest rain expectation will be during the month of July and August considering 99 percent confidence intervals for a 10-year mean rainfall. This gives a strong support to the standard recommendation of ending the sowing of cotton by first weak of June to avoid re-planting of crop. The modified constants of Penman provide best estimates for potential evapotranspiration, total incoming short wave radiation and net solar radiation. The potential evapotranspiration (E_t) is an important component of environment to calculate crop evaportranspiration (ET) to measure crop water use at the location.

Keywords: Potential evapotranspiration, solar radiation, cotton crop, Penmann original formula, Penmann modified formula.