Advantages of grading

    Grading of onion sets has multiple advantages:

    • Large degree of uniformity. 
    • In the larger size up to 20% increase in production.
    • Maximum control is possible on desired grading of final product.
    • Maximum control is possible on desired earliness of final product.

    Please keep in mind that the large size sets (21-24mm) are more susceptible to bolting.

    Yield index


    The earliness of the various size classes can vary by up to 6 days. The larger the onion sets, the earlier maturing it is. A second determining factor is the planting density.

    Graded sizes and earliness

    Graded sizes and size of end product

    For the same planting density and growth period, larger onion sets produce a larger end product. However, the smaller size has a longer growing period and by the final grading can be almost as large as the larger size class. 


    Harvest second year product