Document Type : Original Article


1 Ph.D Student, Agriculture Faculty, Islamic Azad University of Karaj, Karaj, Iran

2 Asistant Professor, Agriculture Faculty, Islamic Azad University of Karaj, Karaj, Iran


Objective: Understanding climate effects on crop yield has been a continuous endeavor aiming at improving farming technology and management strategy, minimizing negative climate effects, and maximizing positive climate effects on yield. Methods: In order to evaluate agroclimate of Corn cultivation throughout the selected substations at Kermanshah province in this current investigation, the statistics data related to daily temperatures within a 10- year statistical period were employed. Deviation from Optimum Percentage (DOP) technique, Growing Degree Day (Active Day Temperature), and thermal gradient methods have been adapted for computation and agroclimatic analysis. Results: The results of this study indicate that the optimal date for cultivation of Corn in high and cold- weather lands (Kermanshah and Eslamabad West) is the of June. Temperature gradient analysis and DOP technique in various heights at the studied region may show that there is one month postponement in deviation from the optimum conditions for optimal cultivation per 100m increase in height of given region. This point is important in terms of date of cultivation and production of commercial product. According to the acquired farming calendar, of June is the most appropriate time for cultivation in this area and thus date of harvest will be the end of September.  


Allmaras, R. R., W. C. Burrwows, and W. E. Larson, 1964: Early growth of corn affected by soil temperature. Soil Sci. Soc. Amer. J., 28, 271ñ275.
Davis, F. E., and J. E. Pallesen, 1940: Effect of the amount and distribution of rainfall and evaporation during the growing season on yields of corn and spring wheat. J. Agric. Res., 60, 1ñ23.
Coelho, D. T., and R. F. Dale, 1980: An energy crop-growth variable and temperature function for predicting corn growth and development: Planting to silking. Agron. J., 72, 503ñ510.
Huff, F. A., and J. C. Neill, 1982: Effects of natural climatic fluctuations on the temporal and spatial variation in crop yields. J. Appl. Meteor., 21, 540ñ550.
Offutt, S. E., P. Garcia, and M. Pinar, 1985: Potential benefits to agriculture of augmenting precipitation. J. Wea. Mod., 17, 23ñ29.
Runge, E. C., 1968: Effect of rainfall and temperature interaction during the growing season on corn yield. Agron. J., 60, 503ñ 507.
Smith, J. W., 1903: Relation of precipitation to yield of corn. USDA Yearbook 1903, USDA, 215ñ224., 1914: The effect of weather upon the yield of corn. Mon. Wea. Rev., 42, 78ñ87.
Voss, R. E., J. J. Hanway, and W. A. Fuller, 1970: Influence of soil management and climatic factors on the yield response by corn to N, P, and K fertilizer. Agron. J., 62, 736ñ740.