RELATIVE POTENTIAL YIELDS

When making a late plant or replant decision, it is important to consider the likely yield potential of the late-planted crop.

Considerations for replant:

• Potential crop yield of existing plant stand vs potential crop yield of replant plant stand (potentially relevant after heavy rainfall events).
• Additional resources required to grow crops i.e. soil water and nitrogen application.
• Potential returns from alternative crops.
• Or cost of maintaining the fallow.

The CSD replant calculator can assist decision making, the FastStartTM Cotton POP app (downloadable from the app store), can be used for a quick assessment of plant stand variability. CSD has developed the first flower calculator, Stimulated Time to Estimated First Flower (STEFF), that can be used to predict the date of first flower and assist in management decisions.

The late planted crop can present many agronomic and pest management difficulties for growers and consultants. Crop agronomy must account for the reduced season length to complete fibre maturity and boll opening before first frost. Late season insect control can be difficult and costly due to resistance and the relative attractiveness of
late cotton crops to Helicoverpa, mites, aphids and whitefly.

For areas where season length is short, you will need to stick to your last effective flowering date so you don’t attract potential discounts due to fibre quality concerns. CSD’s suite of tools, including STEFF, can assist in this decision making process by assessing if you have adequate time to grow a successful crop in your region.

LATE PLANT VARIETIES

There are several important factors that should be considered when making varietal selections for late-planted situations.

• Some varieties are more responsive to management for earliness, so will accumulate fruit earlier than indeterminant varieties. Speak to your local CSD E&D agronomist for which varieties best suit your region.
• Boll load of late planted crops will be filling (and fibre maturing) during cooler than average weather. Last season many crops failed to mature fully which resulted in significant quality discounts.
• Late planted crops with excessive vegetative growth may lead to issues with management of late season insects.
• Crops maturing under cooler conditions may be at increased risk to various plant diseases.
• Late maturating crops may be predisposed to defoliation issues.