The environmental stresses and the very warm late September and early October were more likely the cause of stalk rot. Some fields are standing better than others but cannot be attributed to the factors mentioned. I think the fertilizer rate should be based on soil tests, crop and yield goal. If yield goal is higher when planting thicker, then it will take more fertilizer. Prussic acid is found in sorghums, birdsfoot trefoil, Johnson grass, and chokecherry leaves.
Leaves contain higher prussic acid levels than stems.
The level increases with drought and other condititions that reduce growth. Prussic acid is lost on drying or curing forages for hay or lost during silage storage. Following a frost, prussic acid is most toxic Do not let animals graze crops listed above until the plant material has dried or cured which may take a few days or a few weeks. New growth from sorghum crowns are highly toxic. Dried forages or silages normally have lost most of the prussic acid.