Ground Cover North : GroundCover 134 May-June 2018 - North
By Liz Wells n In Australia’s summer-cropping heartland, mungbeans are gaining ground as more than just a double-cropping option in wet summers. Adding to the appeal of the short-season crop has been its ability to pay its way in seasons such as 2016-17, when fierce heat and patchy rainfall cruelled many sorghum crops. Graham and Sarah Burt, and their son Henry, are regular growers of the summer pulse, and contributed to the record national mungbean crop grown in 2015-16 of 180,000 tonnes – more than double the five-year average. The Burts say mungbeans are helping to spread risk on their farm south-west of Dalby, on Queensland’s Darling Downs. “We are trying to grow our crops on stored moisture, and then hopefully pick up a rain event during the growing season to maximise yield and profitability,” Graham says. “Mungbeans were once considered to be just an opportunity crop, but now they are part of our rotation with wheat, barley, chickpeas and sorghum.” Grower and Landmark Harcourts Dalby agronomist Daniel Skerman says mungbeans often failed as a double crop because they ran out of moisture and yielded poorly, especially in recent drier seasons. “Where we are getting success is when they are planted into a paddock that was fallowed over winter, or winter and the previous summer,” Daniel says. “That’s when they can yield 1.5 to 2.5 tonnes per hectare and return a good profit if they get rain at flowering time to help fill the pods.” Price depends on quality, with indicative values in recent years being upwards of $1000/t delivered to the Darling Downs for the Australian Mungbean Association’s No. 1 grade, $900/t for processing and $800/t for manufacturing. Daniel says improved modern, large-seeded, shiny green mungbean varieties such as Jade-AUA and CrystalA make hitting yield and quality targets easier, but vigilance, and sometimes spraying, is needed to minimise the impact of fungal diseases and insect pests, and a recent arrival, the phytoplasma virus. “Mungbeans have more production risks than sorghum, but the benefit is their superior ability to convert millimetres of rain into dollars.” Both Daniel and Graham say findings from the GRDC’s upcoming ‘Optimising Mungbean Yields’ project, led by the University of Queensland’s Dr Marisa Collins, will generate some new guidelines to enhance understanding of the crops’ susceptibilities, nutritional needs and water use. The project aims to lift the average yield from 0.9t/ha to 2t/ha in a growing area that spreads from southern NSW to the Burdekin in northern Queensland. Australia’s key mungbean markets are India and Myanmar. o Feature: Page 5 PHOTO:LIZWELLS REGIONAL EXTENSION REPORT PAGES 41 TO 43 WITH THIS ISSUE MOUSE CHEW CARDS ISSUE 134 | May – June 2018 By Dr Gio Braidotti Abreak from the conventional breeding strategy of the past half-century is pointing to a promising alternative pathway to breaching the wheat yield ceiling. From the Green Revolution onwards, the driver of breeding efforts to lift wheat’s yield potential has been what is called the ‘Harvest Index’ (HI) – the proportion of grain to straw. But a new approach taken by CSIRO’s Dr Richard Richards – and which is gaining international attention – has changed the focus from HI to total biomass; specifically, changing wheat’s canopy architecture. Breeding for more upright leaf growth in the four-week period before flowering, similar to what has already been bred into maize and rice, increases the capture and penetration of sunlight by the canopy. This means greater photosynthesis because of more light capture by the whole crop, stronger straw, less lodging, greater green leaf area duration, more fertile tillers – and, ultimately, more grain production. Preliminary evidence also points to greater tolerance of leaves to high temperatures. To date, in trials, this combination of enhancements has been increasing yields by as much as 20 per cent in experimental lines. In other words, the more upright leaf structure WHEAT LEAF STRUCTURE A NEW CHANCE TO BREAK YIELD CEILING allows light to work harder for the plant and increase the plant’s grain-producing capability. This potential for improved yield was even observed with older ger mplasm that has yet to be crossed with better adapted, more modern wheat varieties. The finding has global significance and the new approach is already being adopted by researchers with the International Wheat Yield Partnership and in trials underway at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico using the CSIRO lines that express the erect canopy trait. The reason for the excitement is that there has been general consensus that HI is reaching its theoretical maximum capacity to deliver yield gains in wheat, and many people are worried about a looming food crisis for this staple crop. The biomass approach may offer a way around this. Dr Richards has played a central role in alerting the world to the looming yield-gap crisis (see GroundCoverTM 101, November– December 2012, ‘Yield ceiling becomes the breakthrough must’). Now his research has opened up a new route to biomass-driven yield gains. His work is based on longstanding theoretical considerations that predict a yield Continued: Page 3 Mungbeans step up as a summer staple Grower and Landmark Dalby agronomist (right) Daniel Skerman with Henry Burt in a crop of Jade-AUA mungbeans on the Burts’ property at Samford, south-west of Dalby.
GroundCover 133 March-April 2018 - North