Key Points
- Maize seedlings can be damaged through a variety of means, affecting crop growth and yield.
- This study, conducted in Hastings and Chertsey, investigated the time of early season total defoliation by cutting plants to ground level at growth stages up to V8 (eight fully emerged leaves).
- Defoliation up to V4 had minimal effect on forage and grain yield. However maturity appeared to be delayed, affecting grain and forage moisture; the later the defoliation, the greater the impact.
- The impact of defoliation at V6 will depend on whether the crop regrows from the main stem or from tillers. V6 yields were more affected where regrowth was from tillers (Hastings) than main stem (Chertsey).
- Plants cut at V8 did not survive as the growing point of the plant was destroyed by defoliation.
- This simulated damage (defoliation by cutting) does not take into account other impacts associated with defoliation in field situations, such as soil compaction, freezing, shear stress, bruising or other secondary impacts.