Seasonal variations in the growth duration of some rice varieties grown in Cross River State
Two experiments were carried out in 2008 and 2009, in four locations in Cross State, to determine seasonal variations in the commonly grown rice varieties. Their response to different photoperiod treatments were investigated with rice plants in polyethylene bags subjected to varying lengths under artificial light. High photoperiod - sensitive varieties, showed significant difference in their maturation periods when planted at different times of the year. The longer growth duration occurred when plantings were made in January - February. The shortest growth duration occurred when plantings were made in the October - November period. In some of the photoperiod - sensitive varieties, there were big differences in the growth duration when planted in the same month, of different years. These varieties would be unsuitable for planting during the off season (August to September). The results are discussed in light of photoperiod sensitivity of some rice varieties planted at different times of the year.
KEYWORDS: Seasonal variation, growth duration of rice.