Crops are now being planted earlier, even before the opening rains, due to increased adoption of no-till. While early planting can improve crop establishment, crops may also flower earlier. Yields can also be higher in dry seasons as long as frosts are not a major issue. However, on long-term average, the effects are not always large.

The optimal planting time for wheat is a compromise. Planting early will increase the chance of frost damage at flowering. With late maturing varieties, it can also increase the bulk of crops and lead to stored soil water being used before flowering. In early maturing varieties, sowing early may actually reduce the bulk of the crop as development is hastened, as well as reduce rooting depth. This can lead to reduced yield potential and reduced access to deeper moisture and nutrients.

Key Points:

• Early sowing can accelerate establishment and make full use of the growing season but can increase the risk of frost during critical growth stages and hayingoff in a dry finish.
• Flowering time of wheat is controlled by the interaction of several factors that can include temperature, day length and cold requirement.
• Most Australian wheat varieties flower in response to the accumulation of warm temperatures. Many varieties also have a cold temperature requirement and some varieties flower in response to longer days.
• Winter wheats can be sown earlier than spring wheats in suitable regions as the cold requirement delays flowering.
• To minimise risk, varieties with a range of flowering dates and maturities should be sown, providing other criteria such as disease resistance are also met.
• The relationship between sowing date and crop development can interact with disease development and nutrition management.
• Late sowing can increase severity of most root diseases early sowing increases severity of a number of leaf diseases. Rusts are not consistently affected by sowing time.

Want to link to this fact sheet?

Use www.grdc.com.au/GRDC-FS-TimeOfSowing to ensure your link remains current and up-to-date!

• 1.28 mbTime of Sowing Fact Sheet: Northern RegionBalancing the risk for wheat: The optimal sowing date results in wheat flowering after the last frost but before heat stress events begin. Adequate reserves of soil moisture must also be available.
• 1.83 mbTime of Sowing Fact Sheet: Southern RegionImpact on yield and quality of wheat: The optimal sowing time for wheat is a compromise. Sowing too early increases the risk of frost damage and haying-off, while sowing too late increases the chance of grain filling during increasingly hot and dry conditions. By understanding the factors that influence time of flowering, better decisions on what to sow and when can be made.
• 1.79 mbTime of Sowing Fact Sheet: Western RegionWhen to sow wheat to minimise risk: The optimal sowing date results in wheat flowering after the last frost and with adequate reserves of soil moisture before heat stress begins.