Over the past several weeks I've be photographing pecan shuck-split and collecting nut samples. If you look at enough nut clusters like I do, you will usually come across a cluster that has one nut that doesn't seem to split at the same time as all the others (yellow arrow, photo at right). In fact, the shuck stays green and tight all the way until first Fall freeze and never opens. Whats going on here?
The cluster pictured above yielded four nuts (photo at left). Three of the nuts were easily removed from split shucks. The forth was tightly held inside a green shuck.
I cut each nut in half to inspect the kernel within (photo at left). The three normal pecans were fully packed with kernel. The nut with the tight green shuck had the remnants of a kernel that stopped growing at the water stage (early August). Judging from the color of the unfilled seed coat, this kernel was aborted by the tree for some unknown physiological reason. If the seed coat had been colored jet black, the nut would have been the victim of stinkbug feeding. If the nut had been hollowed out by pecan weevil, I would have found worms inside the green stick-tight. In each case, lack of kernel fill prevents the pecan shuck from opening properly.
