Chronology of tiller emergence and tiller orientation in rice(Oryza sativa L.)

The rice plant produces different number of tillers including primary, secondary and tertiary tillers which emerge at different stages of growth. The conventional concept that high tillering rice plants produce more yield is being replaced by a new plant type concept in which optimization of tillering is the objective. A study was conducted to analyze the chronological sequence of tiller emergence and the pattern of tiller orientation in rice varieties Cherumodan, IR36, Ponni and Chitteni grown under uniform experimental conditions. The varieties showed specific periodicity for the emergence of primary, secondary and tertiary tillers intercepted by gap periods. Primary and secondary tillers were produced by all the four varieties but tertiary tillers were produced by IR36 only. Tertiaries and late emerged secondaries were in their juvenile growth stage when the plants were ready for harvest and hence not contributed to grain yield. The varieties showed certain specificities in the alternate axial origin of tillers and their development and orientation.

Author : K.V. Mohanan and K.Pavithran