Evaluation of growth variables behaviors in varieties of Japonica rice under rainfed favored condition

Abstract

With the objective of analyzing the behavior of the variables in the growth of three rice varieties (Toyahatamochi, Kiyohatamochi and Akitakomachi) under favored rainfed conditions, this research was conducted. A randomized block experimental design with three treatments and four replications was employed. The dry mass (g) and the leaf area (m2) of the rice plants in an area of 0,125 m2 in each experimental plot, starting 25 days after germination, was determined. The growth dynamics of these variables was fitted to a second-degree polynomial exponential mathematical function, y = e (b0 + b1x + b2x2). Then, the absolute growth rate (TAC) was calculated. The amount of roots which are present in the soil at 10,20 and 30 cm of depth, in the grain filling phase, was determined. These data were processed using a dual classification ANOVA, using the multiple range test of Duncan (p<0,05) for comparing means. The results of this work showed that variety Kiyohatamochi presents the best features from the point of view of growth for favored rainfed conditions in the region, since it has a good behavior in the development of the leaf surface. It also presents the best results referred to the dry mass production, variable that is closely related to the final yield of the crop, also has a good vertical root system.