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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 / locationFrance / Rubescourt (80) in Picardie
ObjectivesEnhance white onion yield by addition of K in form of Multi-K
Haifa product testedMulti-K
Application methodSide dressing
Tested treatment1 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 treatmentFresh 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 treatment432 - 161= US$/ha
Benefit/Cost ratio432 / 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.

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


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Need more information about growing onions? You can always return to the onion fertilizer & onion crop guide table of contents