Physiological traits of the initial growth in rainfed rice plants in response to seed treatment with micronutrients

Resumo

The study aimed to analyze the effect of seed treatment with micronutrients on the growth of rainfed rice plants. Treatments consisted in the absence of micronutrient application, single applications or a combination of five micronutrients applied to seeds: compound Zinc + Molybdenum (Mo 2.3, Zn 3.5 % w/v) in a dose of 2 mL kg^-1 seed; Copper + Molybdenum + Zinc + Manganese (6.7 Cu, 3.2 Mo, 15 Zn; 9.4% Mn w/v) at a dose of 3 mL kg^-1 seed; Zinc (100% Zn p/v) at a dose of 2 mL kg^-1 seed, Manganese (50% Mn w/v) at a dose of 2ml kg^-1 seed, Boron (3% B w/v) at a dose of 3 mL kg^-1. Plants were collected at, three, seven and eleven days after emergence with readings of leaf area and estimates for dry weight of shoots and roots. From these data calculations were derived for the total plant dry mass, shoot/root ratio, ratio of leaf area to leaf mass and the specific leaf area. The compound mixture of Cu + Mo + Zn + Mn provided the highest seedling dry matter accumulation and highest leaf area, while single zinc applications stimulated the accumulation of root dry mass. Seed treatment with micronutrients provides better performance for the initial growth in rainfed rice plants.