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Effect of four planting dates on grain yield of three hybred corn (Zea mays.L) whit different maturity group (early , medium and late maturity) were evaluated in esfahan for two years
Result of this experiment showed that temperature in various planting date has a pronouced effect on biomassand grain yield.
Based on the results , the best playing date for isfahan is from ordibehesht 20 through khordad 10 th . If this planting date is selected , farmer has a achoice of planting barely for forage or cover crops before plantig corn