Desenvolvimento vegetativo da ervilha cultivada em terras baixas

Abstract

The objective of this work was to determine the plastochron for the pea crop cultivated in lowland. The experiment was conducted at the Federal University of Pampa, Campus Itaqui-RS, in the 2016 and 2017 years. The experiment was composed of three sowing seasons, the cultivar used was Luciana n° 50. A total of 133 plants were implanted in season 1, 168 plants in season 2 and 133 plants in season 3, and the number of nodes in each plant was evaluated. The plastochron was obtained by inverse of the linear coefficiet of regression between the number of nodes accumulated in the main stem (NN) and the value of the accumulated thermal sum (STa). The daily thermal sum (STd, ºC day) was calculated by the expression: STd = [(Tmax + Tmin) / 2 - Tb]. The accumulated thermal sum (STa, ºC day) was obtained by the sum of STd: STa = Σ STd. The plastochron varies according to the cultivation season, being that found for the crop 38,20 ° C day node-¹. This fact is also related to high temperatures during the conduction of the culture where there occurred a greater reduction in the speed of nodes appearance.