Controlling chick pea diseases
On-farm hygiene (fallow management)
The Ascochyta fungus is carried over from one season to the next on infected chickpea seed, chickpea stubble and
volunteer chickpea plants.
The fungus can build up rapidly on volunteer plants, especially if wet conditions are experienced during the spring-summer period.
Monitor chickpea stubble paddocks and volunteer plants for any
evidence of Ascochyta over the summer-autumn period (especially after heavy rain, flooding or strong winds).
To reduce the potential impact of diseased stubble as a source of infection either:
- avoid planting adjacent to, or in proximity to last year’s chickpea paddocks
- maintain a cultivated fallow for 2-4 months, in which all stubble is buried (the Ascochyta fungus only survives 2-4 months when buried), and volunteer chickpea plants are controlled.
Paddock selection
Growers should aim to separate this year’s chickpea crop from last year’s chickpea stubble by as great a distance practical. The Ascochyta blight pathogen can survive in infected chickpea stubble, which can be spread from an infected paddock by wind or overland water movement. While a minimum distance of 500 m is recommended, a kilometre or more is preferable when situated down wind or downhill, or on a floodplain. Growers need to re-assess their rotational farming program, and grow chickpeas in a large single block or blocks, rather than scattered in smaller blocks or strips around the farm.
Disease resistant chickpea-crop
Seed quality
Plant high-quality seed that has a low risk of Ascochyta infection. Aim for a plant population of 25-30 m2. All seed should be treated with a registered thiram-based seed treatment, and sourced from a crop where Ascochyta was detected (low-risk seed). Do not mix inoculant directly with fungicide seed dressings. Refer to the product label directions on use.
Seed retained on-farm should be from the cleanest paddocks, preferably those where the disease was not detected during the previous season. Avoid using severely weather damaged seed as it often results in patchy, uneven plant stands, reduced plant vigour, lower yields and uneven and delayed maturity.
Seed for central and coastal Queensland plantings must be sourced from crops grown in Central Queensland.
Avoid varieties highly susceptible to Ascochyta
Avoid planting susceptible and very susceptible varieties in high-risk Ascochyta situations. PBA HatTrick has the highest level of resistance currently available in commercial desi lines suited to southern areas of Queensland, and the preferred variety in high-risk Ascochyta situations. All varieties agronomically suitable for central and coastal Queensland are very susceptible or susceptible to Ascochyta blight.
Agronomic and marketing issues are other factors to consider when selecting a variety.
Chickpea variety ratings
Table 1: Chickpea variety ratings for the common chickpea diseases in Australia.
(Source: Pulse Australia - Northern Certified Chickpea Agronomy Manual.)
*Moti is not to be grown south of Theodore.
Plant on 50-100 cm row spacings
Planting on a row crop configuration (up and back on 50-100 cm rows) is recommended to assist with tram-lining and ground application of protectant fungicides.
Other benefits of wider rows include:
- improved aeration, which can slow the spread of disease
- more uniform stands from use of precision planters
- option for inter-row cultivation or directed (shielded) sprays
- band spraying, which can cut fungicide/insecticide costs
- more efficient harvesting, especially in lighter crops.
Crops on 1 m spacings can be more predisposed to lodging. This can be partially offset by reducing the target plant population to match the row spacing.
Planting time
Plantings made prior to the recommended planting window tend to be more vegetative, and are more predisposed to frost, Ascochyta and Botrytis grey mould. Weigh the risks against problems encountered with delayed planting.
