Efectos de la temperatura en la emergencia y el crecimiento inicial de ca？a planta y primera soca, variedad TUCCP 77-42

the purpose of this research was to evaluate the effects of temperature on emergence and early growth of tuccp 77-42 sugarcane plant and first ratoon crops, under field conditions and without water limitations. data derived from ten similar and successive planting (plant cane) and harvesting (first ratoon) times from june to november, under optimal growth conditions at a subtropical site (las talitas, tucumán, argentina: 26o 48' s, 65o 12' w). analysis showed that the effects caused by planting and harvesting dates were mainly related to thermal conditions, with temperature being the most influencing factor on emergence and early growth dynamics in plant cane and ratoon crops. thermal factor showed a close relationship with final emergence and average emergence rate, stem elongation and leaf appearance. highly significant inverse relationships with emergence, elongation duration, as well as expanded leaf appearance, were established. under a similar thermal regime, emergence percentages for plant cane and ratoon crops did not differ, but because of the larger number of buds available on the first ratoon stubble, a significantly higher number of primary stalks per row meter were established. since emergence stage was shorter in first ratoon crops, emergence, elongation and leaf appearance rates were higher than in plant cane. this signalled an important phenological advance.