Radio Transcript

Welcome to Agritalk.

This week we are going to be talking about things to consider if you have frost damage in crops.

Substantial changes have refined farming systems over the last 40 years, but have indirectly led to practices that result in a higher risk of frost.

Notable trends affecting the risk of frost include:

• earlier sowing times
• use of higher seeding rates
• denser canopy crops from higher rates of early nitrogen
• use of earlier maturing varieties
• new tillage systems allowing for a faster sowing
• a greater proportion of individual properties being cropped 
• an increase in stubble retention

There is no single solution to managing frost. It seems the best we can do in terms of management is to spread the risk and minimise the impact. It is important to integrate control measures throughout an entire enterprise. 

There is an excellent publication called Managing Frost Risk: A Guide for Southern Australian Grains which is the outcome of over 5 years of research across Southern Australia, which discusses a whole frost management in detail.

Following a frost event the early identification of symptoms and assessment of the crop damage is critical to allow for timely crop management decisions to be made.

The two main options for dealing with frosted crops are to harvest as normal or cut for hay. By calculating your expected gross return less your expenses you should be able to calculate the gross margins of both harvesting as normal or cutting for hay.
 
A crop may still be worth harvesting unless more than 50% grain is lost.

With plant compensation mechanisms, especially in pulse crops, the remaining crop will produce heavier grain and fill wider.

Depending on the severity of the frost, numerous cases have been observed where standing crop left alongside crop cut for hay has ended up yielding 50% and more its pre-frosted potential. 

Where severe frosting has occurred in patches in a crop, these can be cut for hay, leaving the rest as standing grain.
 
A decision for hay cutting needs to take into account the accurate crop damage assessment, and potential market and returns. 

Provided the frosted hay is cut early it generally has equivalent energy values to normal hay, but has reduced protein levels. As a rule of thumb, the final dry weight yield of hay is around twice that which would be reaped as grain.

Other methods include slashing, burning, discing, and feeding to stock.

For more information on this or any other edition of Agritalk, please go to www.ruralsolutions.sa.gov.au, click on news then radio.  You will find a link to today’s topic along with lot’s of other handy links.

Information kindly supplied by Tom Yeatman