YIELD AND QUALITY RESPONSES OF GARLIC AND ONION TO EXCESS BORON

This study, conducted in large, outdoor sand cultures, was initiated to determine the effects of excess B on garlic (Allium sativum L.) and onion (Allium cepa L.) and to establish their B tolerances as measured by yield and quality of the marketable product. Boron treatments were imposed by irrigation with culture solutions that contained 0.5, 1.0, 5.0, 10.0, 15.0, or 20.0 mg B/liter. Relative yields of garlic and onion were reduced 2.7% and 1.9% with each unit (mg.liter-1) increase in soil solution B (B(sw)) above 4.3 and 8.9 mg B/liter, respectively. Increasing B(sw) reduced garlic bulb weight and diameter but did not significantly affect onion bulb weight or diameter. Boron concentration in leaves and bulbs was directly correlated to B(sw).