Duração do ciclo e danos por altas e baixas temperaturas em gladíolo em função da época de plantio

The planting date is an important factor affecting the developmental cycle and quality of final product. Indications from the literature are that gladiolus is a species that can be cultivated throughout the year, but in some periods, adverse conditions may occur, reducing the quality of the flower. Two field experiments (Experiment 1: August 2011 to July 2012 and Experiment 2: August 2012 to July 2013) were conducted in Santa Maria, RS, Brazil, to quantify the influence of planting dates on the duration of the developmental cycle and on the quality of flower stems in gladiolus, identifying possible damages by high and low temperatures in the final product. It is concluded that it is possible to cultivate gladiolus throughout the year, but the duration of gladiolus cycle is higher when planting is carried out in periods of low temperatures, and this is important for scheduling the planting date, mainly for meeting specific market demand (commemorative dates). Extreme temperatures (above 35 ºC and below 0 ºC) reduce the commercial flowers quality and even cause the death of plants.