The combination of an early finish to the growing season and recent rainfall holds several potential implications for growers to consider. Among them, regrowth in crops that still have a touch of green.
The level of regrowth, if any, is highly dependent on the amount of rainfall received and subsequent temperatures, and growers are urged to inspect their crops to assess potential growth on a case-by-case basis. Past research and experience however, reveals some lessons to consider in 2018.
BCG research officer Kelly Angel said that in 2016, secondary tiller growth caused headaches, particularly in barley as growers were forced to delay harvest and wait until tillers had ripened.
Management options to speed up this process included crop-topping and windrowing, otherwise growers could ‘wait it out’.
Admittedly, the growing season rainfall tallies are vastly different between 2016 and 2018. However, BCG research conducted in 2016 found barley was particularly susceptible to yield loss if harvest was delayed. A trial at Kalkee had an average yield loss of 2t/ha from delayed harvest of 26 days due to lodging, shattering and grain and head loss.
In 2015, a barley trial at Quambatook received enough rainfall prior to maturity (23mm in September and 14mm in October) leading to secondary tiller formation, especially in later maturing varieties.
Regrowth could be observed in some pulse crops too. Because of their ‘indeterminate’ growth habit, they will re-shoot, flower and pod so long as some part of the plant is still alive. New growth may require desiccation as an aid in harvest. This was observed in some chickpea crops in the Wimmera last year after late frost damage.
Regrowth in a failed crop also represents an opportunity to recover some of the growing costs via grazing livestock. BCG research into grazing a failed hybrid canola crop in 2012 revealed growers should be wary of toxicity to sheep after some tissue tests had more than 4000ppm nitrate. This increased concentration could be due to applied nitrogen prior to moisture or frost stress. To avoid nitrate poisoning, introduce stock gradually and later in the day with full bellies. Provide roughage via bales or allow access to an adjacent paddock and observe animals closely.
Growers are urged to get out and inspect their crops for potential regrowth. Consider forecasts for more rain and temperatures and use your experience: was crop-topping, windrowing or waiting your most cost-effective option? Seek advice from your agronomist or adviser for more information.
The main thing to remember is regrowth is not the end of a crop, but it does need management.
- For more information on this research phone BCG on 03 5492 2787 or visit www.bcg.org.au.
