Seasonal and varietal effects on tiller population development of sugarcane (Saccharum Officinarum L.)

Tillers carry leaves, determine leaf area index and indirectly influence the amount of photosynthetically active radiation (PAR) intercepted by the sugarcane canopy. Tillers develop into stalks, the sink for the products of photosynthesis. The objective of this study was to investigate the effects of seasons and varieties on tiller population development trends and parameters using different varieties (ZN6, ZN7, N14 and NCo376). Three replicated experiments were established in early (March), mid (July) and late (October) seasons at Zimbabwe Sugar Association Experiment Station. The tiller population development parameters were determined in each plot and the data were analysed for seasonal and varietal effects using the mixed procedure of SAS. The tiller development parameters investigated were: peak tiller population (PTP), final tiller population (FTP), thermal time to peak tiller population (TTTP), thermal time per tiller (TTPT) and tiller survival rate (TSR). The order of importance of the parameters was season > variety > variety x season. The study suggested the presence of genotype by environment (GxE) interaction for PTP. The cane yield of the varieties significantly (P mid > late season.