Growth and vegetable yield of Amaranthus hybridus L. as impacted by harvest methods in southern Ontario, Canada

Amaranthus hybridus L. is a nutritious leafy vegetable amaranth species grown primarily in tropical regions. Weedy amaranth species thriving in southern Ontario suggest the edible biotype could also grow efficiently as a crop. Field trials in Guelph, Simcoe, and Stouffville, Ontario, examined yield in response to three harvest frequencies (weeldy, every 2 wk, and every 3 wk) cut at 15 cm above ground level, using two traditional harvest practices (Afro-Caribbean and European) cut every 2 wk, and a control which was not cut until the final harvest. The highest marketable yields and quality measures were observed in plants cut every 2 wk, every 3 wk, and using the Afro-Caribbean cutting technique which selects and harvests thicker stems while leaving new shoots for later harvests. The difference in growth among sites suggests plants prefer warm, well-drained soil. Marketable yield was as high as 4.02 +/- 0.340 kg m(-2) in Simcoe with an average yield across all three sites of 2.37 +/- 0.229 kg m(-2). This demonstrates that A. hybridus has the potential to be grown as a vegetable crop in southern Ontario and that marketable yield can be optimized by method of harvest.