Yield and Physical and Physiological Quality of Salvia hispanica L. Seeds Grown at Different Sowing Dates

Variations in the sowing date of chia (Salvia hispanica L.) reflect directly on the physiological potential of the produced seeds. This study aimed to analyze the yield and the physical and physiological quality of seeds from the main stem and branches of Salvia hispanica plants grown at different sowing dates. A field experiment was conducted in the crop year of 2016/2017 in five sowing dates (16/09/22, 16/10/28, 17/01/03, 17/02/08 and 17/03/24) in a randomized complete block design with four replicates. Harvest at each sowing date was done when 80% of the leaves of each plant exhibited a darker color, indicating that they were dry. Seed yield was determined in each plant compartment (main stem and branches) and final ear length (cm) and diameter (cm) were also measured at all sowing dates. The following physical and physiological tests were performed to determine seed quality: water content, mass of one thousand seeds, germination test, first count germination, length (root and hypocotyl) and dry matter of the seedlings. Chia can be sown from September to February providing seed yield with high physical and physiological quality. The physical and physiological quality of the chia seeds does not differ between main stem and branches. In late sowing, there is the risk of frost occurrence what may impair the physiological quality and the yield of chia seeds. The best sowing month for obtaining higher yield of chia seeds in a south subtropical region is January.