SELF-POLLINATION • E-FREE TRANSLATION.COM • Definition of Self-pollination

... earliest Persian walnuts to start growth in spring, blossoming at Urbana normally in the first half of May. Flowering is protandrous (male flowers first) but with enough overlap of staminate and pistillate blossoms to secure a large degree of self-pollination from the abundant large catkins. Fruit set might be improved, however, by planting nearby another variety with later staminate catkins.[20] The nuts mature from the middle to the last of September and have not ...

— Northern Nut Growers Association Report of the Proceedings at the Forty-Second Annual Meeting • Northern Nut Growers Association