The Northern Chickpea Ascochyta Diaries

These diaries are intended to update chickpea growers in New South Wales and Queensland with the current Ascochyta situation in 2017. They will be updated with observations throughout the season.

30 June 2017 – Should I spray for Ascochyta before forecast 3 July rainfall?

Is a fungicide spray required before forecast rainfall on 3 July? Growers who missed a chickpea Ascochyta spray before the 28/29 June rain event need to consider the following factors when determining whether to spray or not.

  • Chickpea tissue exposed to 28/29 June rain is already infected and spraying post-rain won’t stop that.
  • Rain is forecast for Monday 3 July, but not a major event with most sites predicting <1-5mm.
  • Growers using a ground rig would need to start spraying 1st or 2nd July.
  • The amount of new growth from 29th June to when spraying starts (2-3 days) is one leaf.
  • The time from infection to new inoculum (latent period) for HatTrick, Boundary and Seamer is currently 7-10 days depending on temperature.
  • The infected chickpea residue that was in the paddock at planting AND Ascochyta infections resulting from May and 10 June rain events are the only sources of inoculum for 3 July infection. This inoculum is available to infect new leaves and older tissue not infected during 28th and 29th June rain event.
  • Is this the best use of my of Ascochyta fungicides?

These factors combined indicate that spraying before the rain of 3 July is NOT warranted on any variety. This recommendation also applies to crops that missed Ascochyta sprays before the mid-June and/or late May rain events which will have been infected during the 28/29 June rain. After next week’s rain, crops should be monitored for Ascochyta and be sprayed before the next infection event (>3mm and >3hrs leaf wetness).

For further information or clarification on the above recommendations please contact Kevin Moore, NSW DPI (details at end of this post).

24 May 2017

Figure 1. Ascochyta blight stem lesion at 5-6 node stage

Ascochyta blight has been found in a chickpea crop in QLD by a local agronomist; the diagnosis was based on symptoms and presence of pycnidia in leaf and stem lesions (5-6 node stage) (see Figure 1). Samples are being sent to Dr Kevin Moore, NSW DPI plant pathologist for confirmation. The crop was planted in the last week of April and received 15mm rain on 13 May 2017. It was not sprayed with a fungicide before the first post emergent rain. The outbreak may have involved seed borne Ascochyta but the multiple lesions on infected plants indicate a high level of Ascochyta inoculum was in the paddock at planting as infected chickpea residue from the 2016 crop (ie chickpea on chickpea).  The grower has been advised to apply a registered fungicide before the next rain event. This proactive management strategy should mean the disease is manageable. The video below provides an overview of how to scout for, identify and manage Ascochyta blight in chickpeas.

21 April 2017

High grain prices are tempting at the best of times, particularly when another rotation staple is at historical lows. However, breaking rotations and going back-to-back is a particularly risky business with chickpeas, and Senior Pulse Pathologist Kevin Moore is strongly advising against chasing these high prices at the expense of integrated disease best management practice. Read more in Back to back a bad call for chickpea growers.

Background

Following a high incidence of Ascochyta blight in 2016 chickpea crops throughout northern NSW and Queensland, there will be a large amount of ascochyta inoculum to infect 2017 chickpea crops. Growers management of Ascochyta inoculum will be key to reducing the impact on 2017 chickpea crops. All varieties rated susceptible or moderately susceptible should be treated before the first post rain emergence event.  

Think you’ve found Ascochyta?

If you suspect your crop has Ascochyta (or any disorder) wrap the plant material in slightly moist (not wet) newspaper and send to:

Northern NSW and QLD Growers

Kevin Moore NSW DPI
4 Marsden Park Rd
Calala NSW 2340

Contact: Phone – 0488 251 866, Email – kevin.moore@dpi.nsw.gov.au

Southern Region Growers

Courier:
SARDI, Plant and Soil Health
Plant Research Centre
Gate 2B, Hartley Grove
Urrbrae SA 5064

Postal:
SARDI, Plant and Soil Health
Locked Bag 100
Glen Osmond SA 5064

Contact: Dr Jenny Davidson, Science Leader, Plant Health and Biosecurity, Phone – (08) 8303 9389, Email – jenny.davidson@sa.gov.au

More information

 

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