Australian Mungbean Association
Australian-grown mungbeans have quality written all over them!
Never give up on mungbeans until they are dead
Alan Obel, grain grower, from Wooroolin and Ian Crosthwaite, Senior Agronomist, BGA AgriServices, Kingaroy.
14 May, 2016
by Cindy Benjamin
Mungbean crops continue to surprise BGA senior agronomist Ian Crosthwaite. “At planting it is impossible to know exactly how the season will unfold but mungbean is showing itself to be a very reliable performer even under poor growing conditions,” he said. “One crop in particular last season was drowned at planting, faced strong early weed competition and was inundated again at the 2-leaf stage and yet went on to yield 1.5 t/ha with minimal agronomic intervention. All we did was apply herbicide when the crop began to flower and one insecticide spray at mid flowering.”
“When it comes to making yield there are many variables that come into play—some of which are easier to influence than others,” said Mr Crosthwaite. “The easiest things for the grower to control are plants per hectare and the percentage of beans that go in the bin at harvest. Other factors such as racemes per plant, pods per raceme, beans per pod and bean size are more difficult to influence and can vary considerably from one season to the next.”
“The big question is what would it take to produce just one more pod per plant?” he said. “This alone could conservatively add 0.22 t/ha to the yield.”
How this can be done however remains largely unknown. Mr Crosthwaite believes that one possibility is to increase the use of nitrogen fertiliser and reduce the reliance on the crop’s ability to fix nitrogen. “Additional nitrogen fertiliser has the potential to lift the average yield by around 0.5 t/ha, adding significantly to returns with minimal extra cost,” he said. “Many growers are looking closely at improving crop nutrition and attending to drainage problems so the crop has the best opportunity to reach its potential yield.”
Flower shedding in mungbean is a normal response to growing conditions however the more flowers that are retained, and pods filled, the better. “Mungbean plants produce between 5 and 15 flowers per raceme and can lose 40 to 70 per cent of these flowers in hot, windy conditions.”
“Planting date calculations need to take into account the likely timing of temperatures over 33 degrees C, dry winds and rain—all of which can lead to flower drop,” he says. “The other factor that growers have some control over is insect pressure, so frequent monitoring and timely spray application is critical to maintaining flower numbers.”
“Altacor is proving to be a very useful product, providing knockdown action on small helicoverpa, looper, bean pod borer caterpillars as well as providing a significant residual effect,” said Mr Crosthwaite. “Being such a good product and being registered for use in a range of crops including mungbean, adzuki bean, soybean, chickpea and cotton, growers need to be doing everything they can to prolong the life of this chemistry and avoid insecticide resistance.”
“For best results, follow the manufacturer’s ‘critical application parameters’, including water volumes over 100 L/ha, medium droplet size and vehicle speed below 20 km/hr. And consider using higher water volumes and a different nozzle setup if the crop is particularly large or dense,” he said.
Being an indeterminant plant, mungbean crops generally require desiccation. “I believe Reglone has been unfairly blamed for some poor desiccation results,” said Mr Crosthwaite. “For best results it is important to use water rates greater than 125 L/ha and a product rate of 3 L/ha. The best time to apply is at night or under overcast conditions. Desiccants also work better when powdery mildew is controlled.”
Harvest losses are often significant and small improvements can make a large difference. “Paying close attention to harvester setup to minimise extraneous matter while maximising beans in the bin is critical,” he said.
Mr Crosthwaite also recommends that growers be familiar with the mungbean quality standards, which are available on the Australian Mungbean Association website, and the benefits of grading. “Grading losses can range from 8 to 20 per cent and insect damage and staining both affect the grain quality and marketability of the consignment and are things that growers can influence during the season,” he says. “The value of grading however is apparent when a portion of the harvested grain achieves a higher grade rather than the whole consignment being downgraded to the lowest common denominator.”
“Develop a good relationship with a grain buyer to understand the quality parameters they are monitoring and the markets that they sell into. Not all buyers and marketers are selling into the same markets,” he said.
Also be aware of the marketing implications of using particular crop protection products that have Maximum Residue Levels (MRL) associated with them. Although registered for use, MRL applies to glyphosate, paraquat, haloxyfop and tebuconazole and it is essential that all sectors of the industry comply with MRLs and declare the use of all crop protection products used.
“There are several good reasons why good quality seed is important to the success of a mungbean crop and these are generally well understood,” said Mr Crosthwaite. “If for no other reason, buy AMA approved seed or have your retained seed tested for seed-borne bacterial disease because there is no in-crop treatment if these diseases are present and take hold of the crop.”
More information: www.mungbean.org.au