Chickpea farmers are advised to inoculate either their seed or soil at sowing with commercially-produced and marketed inoculants, because the rhizobia that fix nitrogen are not usually present in the soils in which the legumes are grown.

The poor result from uninoculated chickpeas in a recent trial at Narromine highlights the low level of native rhizobia for chickpeas in Australian soils.

"Generally, inoculation is recommended for all chickpea crops, as the cost of poor nodulation far outweighs the cost of inoculation," Coonamble district agronomist, Rohan Brill, said.

"Seed applied treatments have mostly been used in Australia, however, there are a now a number of granular inoculants on the market that are applied ‘in furrow’," he said.

The advantages of granular inoculants include ease of use (provided a separate box is used on the seeder), less exposure to seed applied fungicides, and more even distribution in the soil.

Trials in North America have shown consistent yield improvements of approximately 20 per cent when using reliable granular inoculants.

However, Mr Brill says results of Australian research have been less consistent.

"The granular products generally come at a higher cost, principally because they need to be applied at higher rates, between three and 10 kilograms per hectare," he said.

A small plot trial was set up in 2008 at Narromine by NSW DPI staff from Trangie and Dubbo, with the aim being to compare some of the commercially-available inoculant products. The products used were:

• Nodulaid - Standard peat inoculant
• EasyRhiz - Freeze dried inoculant
• Nodulator - Clay based granular inoculant
• Alosca - Clay based granular inoculant
• N-Prove - Peat based granular inoculant

The Nodulaid and EasyRhiz treatments were applied as liquid slurries to the seed, while the granular treatments were applied in furrow with the seed.

The N-Prove product had the best nodulation scores, with 100pc of plants nodulated and with nodules on lateral roots as well as around the crown.

The Nodulaid and EasyRhiz treatments had 100pc and 97pc of plants nodulated respectively, but with nodules confined only to the crown of the plant.

The Nodulator and Alosca products provided variable nodulation, with 67pc of plants nodulated.

The uninoculated treatment had just eight per cent of plants nodulated.

Further evaluation of the various formulations is required.

These data are from one site in one season only, and need to be replicated both in space and time.

Further paddock-scale work will be done in 2009, looking at streaming of inoculants using liquid injection systems, as well as applying inoculants (liquid and granular) at varying depths.

Contact Rohan Brill, Coonamble, (02) 6822 1000, rohan.brill@dpi.nsw.gov.au

Ascochyta fungicides for 2009 chickpea growers

Chickpea growers may have limited fungicide options for managing Ascochyta in 2009.

The year will be a serious risk season for chickpea Ascochyta blight.

High levels of Ascochyta during the 2008 chickpea season in northern and north central NSW means there will large amounts of inoculum of the fungus ready to infect 2009 chickpea crops.

If conditions favour the disease in 2009, chickpea growers will need to be vigilant if they are to avoid losses from Ascochyta.

Several options before planting can reduce Ascochyta risk, and are available on the Pulse Australia web site (see contact details below).

However once the crop is in the ground, Ascochyta management depends on the use of in-crop foliar fungicides.

Currently only one chemical, mancozeb, can be used for chickpea Ascochyta.

Chlorothalonil, the other chemical growers used in 2008 and previous seasons, can not currently be used - its permit (PER9814) ran out in January.

Whether chickpea growers can use chlorothalonil in 2009 to manage chickpea Ascochyta depends on the outcome of a residue review currently before the Australian Pesticides and Veterinary Medicines Australia.

If chlorothalonil is not available in 2009 and it is a favourable year for Ascochyta, chickpea growers need to be aware of some key facts.

Mancozeb does an excellent job on chickpea Ascochyta provided it is used as a protective fungicide, that is crops need to be sprayed before infection occurs.

Growers should think very carefully about growing varieties that are susceptible to Ascochyta, for example, Jimbour and Kyabra, if mancozeb is the only chemical available.

Managing Ascochyta on Jimbour in a season conducive to disease will be challenging, and it will require mancozeb rates above the usual rate of one kilogram per hectare of product.

A 2008 Ascochyta trial at Tamworth showed Jimbour with six sprays of mancozeb at 1.0kg/ha product yielded 638kg/ha less than it did with six sprays of chlorothalonil at 500mL/ha product.

Missing one or two fungicide sprays on Jimbour or Kyabra will make salvaging the crop with mancozeb extremely difficult even at high rates.

Growing varieties that have improved resistance to Ascochyta will make managing the disease with mancozeb less risky.

In the trial mentioned, Yorker sprayed six times with mancozeb at 1.0kg/ha yielded only 110kg/ha less than six sprays of chlorothalonil at 500mL/ha.

For Flipper and Genesis 425, mancozeb out-yielded chlorothalonil, giving 289kg/ha more yield with Flipper and 123kg/ha more with Genesis 425.

Other Genesis lines were not in the trial but should perform similar to or better than Genesis 425.

The research that derived the comparisons was funded by the Grains Research and Development Corporation project, More Profitable Chickpeas through Disease Management and Disease Screening - Northern Region.

Contact Kevin Moore, Tamworth, (02) 6763 1133 or 0488 251 866, kevin.moore@dpi.nsw.gov.au and for options before planting, visit the Pulse Australia web site.

From the bookshop

Chickpea disorders: the Ute Guide

Chickpea - best practice management for sustainable production