Crop diseases have caused serious concerns for growers this year as they have been difficult to manage. Their management will continue to be an issue given the continued wet weather leading up to harvest. Below is some important information that will help growers up to and including harvest.
Also a reminder that the Southern Pulse Agronomy field day is on next Thursday (20th Oct) near Rupanyup. Catch up on all the latest pulse news and speak to the local experts. See the attached flyer for more information.
Pulses
The breakdown of the ascochyta Genesis 090 resistance means that all chickpea varieties should be treated as moderately susceptible to appropriately manage the disease. Further information on the breakdown and how to manage is available here.
Severe botrytis grey mould (BGM) in lentils in the Wimmera and the Mallee have been observed, particularly in MS varieties like PBA Bolt. Continued management will be required as we are headed for warmer botrytis weather and have large, dense and moist canopies. Watch for lesions in the upper canopy as well as the fluffy growth typically seen in the lower canopy as the disease is splashing up onto upper leaves and flowers. Further information for BGM in lentils can be found here.
Faba beans will need to be monitored for chocolate spot and fungicide applied in order to protect flowers and pods where possible. For more information see the Chocolate spot in faba bean article on eXtensionAUS.
Blackspot is present in a number of field pea crops this year due to the cold wet conditions that have allowed the disease to continuously cycle. This has resulted in severe infections in some cases. Field peas which are still flowering and at early podding should be protected with an appropriate fungicide.
Pulse Australia has compiled 2016 fungicide guides for chickpeas, lentils and faba beans that include permits and on-permit usage. These can be found here.
Cereals
CropSafe has been receiving samples from the Mallee during the last few weeks to determine whether yellow leaf spot (YLS) or septoria tritici blotch (STB) was the cause of tan coloured lesions in wheat. Both have been found in the area this season. Septoria tritici can be distinguished from YLS by the appearance of small black fruiting bodies within the lesions. These look like tiny black pin heads in the tan part of the leaf lesion and are the key indicator for STB. While it is unlikely that STB will cause yield loss this season, it will mean that inoculum is widespread next season.
The continued wet weather has meant that scald has become a significant issue in many barley crops, right until grain development. There is little evidence for benefit from fungicide application after flowering. We may also see some grain infections. Leaf rust of barley has been detected in many crops but has not developed as quickly as expected due to the cooler conditions during the last few weeks and proactive application of fungicides. Loose smut has been observed in barley crops in the Mallee. These include susceptible varieties such as Hindmarsh, La Trobe and Spartacus, even where seed treatment was applied and good coverage achieved. It is important to inspect crops to determine if loose smut infections are present.
When retaining seed for next year, ensure that an effective seed treatment is being used and good coverage is achieved. Further information regarding rust can be found here and for smut in barley see the loose smut article here.
Discolouration of grain (cereals and pulses) may also be observed this year due to the conditions and diseases affecting crops. There are a number of causes and if you are unsure, send in a sample to CropSafe.
