Physiological Quality of Rice Seeds Stored in Different Environments and Packages

Aims: Evaluate the physiological quality of rice seeds during storage in different packages and environments, identifying the best condition to conserve the seeds.

Study Design: Completely randomized with four replicates.

Place and Duration of Study: Plant Science Laboratory and Genetics Laboratory of the Federal University of Piauí, Bom Jesus-PI, from April to October 2016.

Methodology: Seeds of rice were stored for 180 days in plastic bottles, kraft paper packaging, trifoliate paper packaging and polyethylene bags in cold and humid chamber (10°C and 85% RH), in a temperature controlled environment (25°C) and in an uncontrolled environment (21-36.4°C and 30-67% RH). The water content and vigor characteristics (first counting germination and germination speed index and electrical conductivity) were evaluated before (control), and at 90 and 180 days of storage, additional tests were also evaluated during these periods the Absolute growth rate of the root (AGRR), Absolute growth rate of the aerial part (AGRAP), Relative growth rate of the root (RGRR) and Relative growth rate of the aerial part (RGRAP).

Results: The values ​​of AGRAP and RGRAP were reduced, differing from the others, for the trifoliate paper packages (0.168 cm day-1) and polyethylene bag (0.168 cm dia-1) in environment 1 at 180 days of storage. The plastic bottles presented the highest values ​​for the characters 1st count (%) and germination (%) in all environments and storage periods. At the end of the storage (180 days) the environment with temperature control was the one that presented the best results of 1st counting of germination (%) and germination (%). At 90 and 180 days, the plastic bottles presented higher Germination speed index. The environment with temperature control presented better results for electrical conductivity (μS cm-1 g-1)

Conclusion: The environment with temperature control is efficient in storing rice seeds for 180 days using a plastic bottle package. During storage, the greatest changes in the physiological quality of rice seeds are verified in the cold and humid chamber environment and in the polyethylene bag package.