100-kernel (100-k) weight, reported in grams (g), indicates a larger kernel size as 100-k weight increases. Kernel size affects drying rates. As the kernel size increases, the volume-to-surface-area ratio becomes higher, and as the ratio gets higher; drying becomes slower. In addition, large, uniform-sized kernels often enable higher flaking grit yields in dry milling. Kernel weights tend to be higher for specialty varieties of corn that have high amounts of horneous (hard) endosperm.
- U.S. Aggregate 100-k weight in 2019 averaged 34.60 g, lower than 2018 (35.07 g), 2017 (36.07 g) and the 5YA (34.94 g).
- Variability in the 2019 U.S. Aggregate 100-k weight (standard deviation of 2.48 g) was lower than 2018 (2.84 g), 2017 (2.53 g) and the 5YA (2.61 g).
- Range in 100-k weight in 2019 (25.11 to 43.93 g) was less than 2018 (23.86 to 45.88 g) and 2017 (23.06 to 46.44 g).
- The 100-k weights in 2019 were distributed with 44.3% of the samples having a 100-k weight of 35.0 g or greater, compared to 50.3% in 2018 and 63.6% in 2017. This distribution indicates a lower percentage of large kernels was found in 2019 as compared to 2018 and 2017.
- The average 100-k weight was lowest for the Pacific Northwest ECA (32.73 g), compared to the Gulf (35.39 g) and Southern Rail (35.16 g) ECAs. The Pacific Northwest ECA had the lowest 100-k weight in 2019, 2018, 2017 and the 5YA.