In the present experiments, 'Marathon F1' broccoli plants were grown in the same geographic location both under conventional and organic production systems. The density of planting was 2.08 plants per square metre. With the conventional system, fertilisers were applied at the rate of 150kg per hectare of nitrogen (N), 60kg per hectare of phosphorous (P2O5), and 200kg per hectare of potassium (K2O). The organic plot had not been treated with herbicides or pesticides for 10 years and, for this experiment, cow manure was incorporated into the soil at a rate of 20,000kg per hectare.
Irrigation was applied throughout the period of the experiment.
Samples were taken from all plots of both treatments at various intervals, from planting up to the stage of commercial harvest, and were processed on the day of collection.
Broccoli florets are an important source of anti-oxidants, and the organically grown broccoli had a better anti-oxidant capacity at the commercial harvest stage. None of the other aspects that were tested showed any difference between the two systems of growing.
Dr Ken Cockshull, Associate Fellow, Warwick Crop Centre, University of Warwick - Proximate composition and anti-oxidant activities of organically and conventionally grown broccoli (Brassica oleracea L. var. italica) by Martinez-Tome, Martinez-Tome and Martinez-Tome (2011). Journal of Horticultural Science & Biotechnology 86 (5): 511-516. The authors' abstract of their manuscript can be seen in full at www.jhortscib.com.