After receiving some welcomed rainfall, I spent some time checking of the progress of our pollination season. All pecan cultivars have pistillate flowers showing and many of our protogynous cultivars have fully pollinated nutlets. One cultivar that was fully pollinated was Oswego (photo at right). After a nutlet is pollinated, the stigma of the flower turns black in color.
Compare the color of the Oswego stigmas (above) to the bright red stigmas now visible on Faith pecan trees (photo at left). Faith stigmas are just entering the stage when they become receptive to pollen. Oswego is an example of a protogynous cultivar while Faith is protandrous. At this point in the season Faith trees have released all their pollen while the pollen sacs on Oswego catkins have yet to open.
If you are watching the pecan flowering process on your trees, the first sign that a pistillate flower has been pollinated is the appearance of black tips of the stigmatic surface. The Posey flowers pictured at right provide a prefect example of a recently pollinated flower.
