When we harvested our Peruque crop this past fall I noticed that the nuts didn't have their characteristic "bottom heavy" appearance. In the photo at right, note that the nut harvested in 2013 is wider at the base than near the apex. This general nut shape is termed "ovate" or egg-shaped and it is the usually shape for Peruque. But in 2014, our Peruque nuts took on a more oval shape where the nut's base and top of the nut were just about the same size.
A quick look at the Peruque nuts we produced this year would have some question if we really had the right cultivar propagated in our orchard. But
over-all nut shape can be influenced by weather patterns and 2014 provided the the perfect example. If soil water becomes limited during the later stages of nut expansion the base of a nut will become smaller in diameter. A period of dry weather in late July was the reason our Peruque nuts did not develop their normal "bottom-heavy" shape in 2014.
Over-all nut shape is not the only way to identify pecan cultivars. Peruque nuts have four, very-characteristic corners on the shell just below the shell's apex. The photo at right shows the same two nuts as seen above but photographed looking down on the top of each nut. On each nut I've drawn a red square whose corners point to the four corners on the shell.
Cracking open a nut is also a good way to gather further evidence of cultivar identity. In cracking Peruque you should find a extremely thin shell. Once the kernels are extracted Peruque has two characteristics that can be used to help verify the cultivar. In the photo at right, note that the dorsal groves of Peruque kernels form a very distinctive "V" shape unlike most pecan cultivars that have parallel dorsal groves. Next, note the deep cleft in each kernel half located at the top of the nut meat. Many pecan cultivars have a small cleft at the top of the kernel but the cleft found in Peruque extends deeper than most.
