White onion bulb’s size increased by Multi-K application


Side dressing of Multi-K was carried out before bulbs enlargement


White Onion / Printon
Country / location France / Rubescourt (80) in Picardie
Objectives Enhance white onion yield by addition of K in form of Multi-K
Haifa product tested Multi-K
Application method Side dressing
Tested treatment 1 x S.D. of 300 kg/ha Multi-K prills before bulbs start swelling
Control treatment results

Marketable yield (bulbs > 35 mm in diameter) = 54 MT/ha
Dry matter content = 15.4%
Marketable dry matter yield = 8.32 MT/ha

Grower’s revenue from fresh yield: 108 US$/MT

Best treatment results

Marketable yield (bulbs > 35 mm in diameter) = 58 MT/ha
Dry matter content = 16.5%
Marketable dry matter yield = 9.56 MT/ha

Grower’s revenue from fresh yield:  108 US$/MT

Characteristics of best treatment Fresh yield increase: 4 MT/ha
1.1% increase in D.M. content, that’s considerable, but not enough for a better price, a bonus is given at 17% D.M.
Increased return = 4 x 108= 432 US$/ha
Cost of treatment (application + material)= 161 US$/ha
Net benefit of best treatment 432 - 161= US$/ha
Benefit/Cost ratio 432 / 161 = 2.68

Good results that justify further experimentation. The results could be more significant unless the plot was severely infected by Sclerotinia, which did not allow complete harvesting.

Reference Illiaquer (a huge private company growing vegetables all over France) & Duclos.