ARE THE PLANT DENSITIES CURRENTLY USED FOR CARROT SEED PRODUCTION TOO LOW?

The responses of seed yield and quality in carrot to a range of plant densities from 100 000 to 800 000 plants ha^-1 (root to seed method) and from 110 000 to 2 560 000 plants ha^-1 (seed to seed method) was examined. Yields of seed from the root to seed method increased from ca. 1 100 to 1 500 kg ha^-1 as plant density increased from 100 000–800 000 plants ha^-1. For the seed to seed method yields increased from 700 to 2 400 kg ha^-1 over the range of densities used. At the highest densities ca. 60% of the seed yield was produced from primary umbels compared with less than 20% at the lowest density. There were no significant effects of plant density on plant height, time of flowering, crop maturity and there was no consistent effect on mean seed weight.