Effect of harvesting wheat and oats at different stages of maturity

1. There appeared to be no advantages from premature harvesting of rust-infected wheat or oats. The yield of Marquis wheat and Victory oats increased from the time the grain was in the milk stage until shortly before maturity. Kernel development failed only when senescence had set in with resulting disintegration of chlorophyll and tissue dessication. 2. Grain quality, as measured by increased weight per bushel and 1,000-kernel weight, was greater when plants were permitted to mature before harvest. Premature cutting, until about six days before maturity, resulted in lowered grain weight in both wheat and oats. 3. The grade of wheat was not increased with approach of maturity, even though the percentage of dark, hard, and vitreous kernels increased to a point near maturity. The bushel weight of both wheat and oats was low enough to cause all grain to be designated as "Sample Grade." 4. No recognizable differences in 1,000-kernel weight were noted for grain from plants dried in the oven immediately upon harvest, dried in shock in regular manner, in shock with culm bases in water, and in bags under the eaves of a building. 5. There were no differences in 1,000-kernel weight of grains attached to the full-length plant as contrasted with seed from severed spikelets. 6. Apparently, transfer of material from the plant to the seed after harvest was too small to appear in increased kernel weight. Both wheat and oats gave increased percentages of dry matter with maturity. With the exception of glumes and grain, this was largely the result of water loss. In glumes and grain the actual dry matter increased. 7. Nitrogen percentage of both wheat and oats decreased slightly with maturity. 8. Nearly mature to mature wheat was decidedly superior in milling and baking value. This was especially true of loaf color. 9. In both crops, straw yields tended to decrease, while grain yields increased as the plants matured. 10. Life action probably continues for some time after harvest as evidenced by the wheat caryopses changing from green to red when left within the glumes but remaining green when dried in an oven. 11. There were no changes in internodal length from the milk stage to maturity. 12. Evaporation of water from plants as measured by the atmometer was greater in shocks built from more mature plants. 13. The percentage of oat hull (lemma and palea) decreased with kernel development during successive harvests. 14. On the basis of these and earlier results, there appears to be no more justification for premature harvest during rust epidemics than during years when no epidemic is present.