The nuts on our pecan trees are finally starting to grow in size. However, pecan cultivars differ in the timing of when the phase of rapid fruit enlargement begins. In the photo at right, I have harvest nuts from three pecan cultivars. Warren 346 is one of the earliest ripening cultivars we have in our collection. Pawnee ripens in late September while Kanza ripens in early October. One of the characteristics of early maturing cultivars is that they start into rapid fruit expansion earlier in the growing season. Note, that by July 6th, the Warren 346 grown larger than Pawnee and even smaller Kanza.
Cutting open each nut you can see that the size of the ovule (small water filled sack that will grow and develop into pecan kernel) also differs between cultivars. Kanza has a small tear-drop-shaped ovule while the ovule of Warren 346 is nearly 5 times the size. Watching the growth and expansion of the ovule is the best way to judge the development stage of a pecan. If you would like to learn how to cut nuts open to check on kernel development check out this post.