Walnut:

a) premium (85-90% of a butterfly) – ripening period: September-May. Walnut diameter: 15-30 mm. Color: from light yellow to pale beige.
b) first grade (65-70% of the butterfly) – ripening period: September-May. Walnut diameter: 15-30 mm. Color: light yellow to light brown.
c) second grade (65-70% of the butterfly) – ripening period: September-May. Walnut diameter: 15-30 mm. Color: light brown to brown.