What we learnt in 2015 and recommendations for 2016 in chickpeas

Note: Recommendations for Ascochyta were revised in May 2016

Take home message

  • Plant seed of known identity and purity and of high quality that has been properly treated with a registered seed dressing. 
  • Localities where Ascochyta was found on any variety in 2015 are considered high risk for 2016 crops and growers are advised to apply a preventative fungicide before the first post-emergent rain event to all varieties including PBA HatTrick.
  • Mild temperatures, long cloudy periods and frequent rainfall events during Jun/Jul across the Northern region as occurred in 2015, are ideal for early season outbreaks of Ascochyta blight in chickpea crops.
  • In wet seasons the management of Ascochyta can be hindered by getting ground rigs into wet paddocks and shortage of fungicides.
  • Follow the disease management recommendations in this article and associated links – they will maximise your chance of a profitable chickpea crop in 2016.

The 2015 northern NSW/southern QLD chickpea season

Unprecedented high prices (peaking at $900 in Jun) led to a record planting of chickpeas in the region.  The 2015 winter crop season in northern NSW/southern QLD followed a wet Jan, dry Feb/Mar, wet Apr (except Dalby) and wet May (except Roma, Table 1).

In most centres in northern NSW, mild, wet to very wet conditions in Jun/Jul were followed by average or below average Aug, a very dry Sep, below average Oct rain and a wet Nov harvest.   On the Downs conditions were much drier.  Rainfall totals and long term averages for the Jun-Nov period were:  Dubbo 292mm (LTA 279mm), Gilgandra 301mm (LTA 261mm), Trangie 251mm (LTA 225mm), Nyngan 204mm (LTA 190mm), Coonamble 158mm (LTA 231mm), Walgett 236mm (LTA 201mm), Moree 204mm (LTA 258mm), Tamworth 341mm (LTA 315mm), Roma 173 (LTA 226mm), Dalby 124mm (LTA 261mm) with monthly figures in Table 2.

With the exception of the Downs and western areas, these conditions, together with early sowing resulted in high biomass crops which used a lot of water.  Cold, dry weather from late August to late September led to flower and pod abortion.  This was not helped by considerable temperature fluctuations in the last 10-14 days of September (up to 20°C in a 24hr period). Hot, dry conditions in early October put crops under further stress (as most had run out of water).  Thus, in many parts of northern NSW, seasonal conditions conspired to produce big canopies that ran out of water during the major pod filling period. Coupled with frosts, low and fluctuating temperatures, this resulted in missing pods, ghost pods or single-seed pods.

Table 1. Jan – May 2015 rain (mm) at selected locations in NSW/QLD

Location

Jan

Feb

Mar

Apr

May

Roma

86

31

33

46

12

Dalby

107

49

13

11

86

Dubbo

131

32

8

82

48

Gilgandra

103

21

3

99

73

Trangie

59

1

11

114

48

Nyngan

91

5

13

44

44

Coonamble

74

11

6

76

51

Walgett

34

0

6

24

30

Moree

105

4

60

63

33

Tamworth

90

23

52

86

38

Table 2.  Jun – Nov 2015 rain (mm) at selected locations in NSW/QLD

Location

Jun

Jul

Aug

Sep

Oct

Nov

Roma

64

12

24

16

16

41

Dalby

10

18

24

15

47

9

Dubbo

72

60

39

8

46

67

Gilgandra

87

59

31

1

32

92

Trangie

44

44

33

3

28

99

Nyngan

51

35

29

7

13

70

Coonamble

39

27

13

4

29

35

Walgett

58

44

27

1

34

72

Moree

62

36

11

4

10

83

Tamworth

109

34

54

24

50

71

Nevertheless, in NSW yields east of the Castlereagh and Newell highways were generally good with the better crops going 2.5 – 3.0 t/ha.  However, farmers west of these highways were disappointed with some crops yielding less than 0.2 t/ha.

In QLD, some crops on the Downs planted on wide rows went >3.0 t/ha with at least one Kyabra crop going 3.6 t/ha. The Downs crops were sown on a full profile but with in-crop rainfall well below average, they did not have a lot of biomass.  This, coupled with wide rows which allowed the soil to warm up, is believed to account for the large yield differences between crops at say Dalby and those at Moree.

Chickpea diseases in 2015

In 2015, 243 crop inspections were conducted as part of DAN00176.  Ascochyta blight, AB (Phoma rabiei formerly called Ascochyta rabiei) was detected in 60 crops. High chickpea prices tempted some growers to break rules, eg plant back to back chickpeas and they paid the price, in terms of AB infection and AB management costs in 2015 chickpea crops that followed 2014 chickpeas.  Some growers reported more AB in PBA HatTrick than they ever saw in Jimbour, but many of these crops had been inundated in Jun/Jul and we know that AB resistance of waterlogged chickpeas is compromised.  Further the genetic purity of the variety could not be determined.  Generally, however, good management and dry conditions through Aug – Oct kept AB under control and no major yield losses were reported.

Phytophthora root rot, PRR (Phytophthora medicaginis, 23 cases) caused light to moderate losses but only in paddocks with a history of medics or where the susceptible variety PBA Boundary was planted.

The mild wet winter also favoured Sclerotinia (24 cases) especially in paddocks with a canola history, with both basal and aerial infections detected.  Where canola was involved, the species was always S. sclerotiorum.  One crop in the wetter areas east of Narrabri had aerial infection from ascospores of S. minor instead of the typical infection of roots and stem base by mycelia from sclerotia. This was the first record in this region for infection from windborne ascospores from sclerotia (due to carpogenic germination of sclerotia) leading to infection of chickpea by of S. minor.  If such windborne infection is common, greater S. minor infection may result. 

Botrytis Grey Mould, BGM (Botrytis cinerea) threatened to be a problem in high biomass crops and some of these were sprayed with carbendazim in early spring.  This together with the hot dry finish, diminished the risk of BGM and no damage was reported. 

Across the region, viruses were uncommon only reaching damaging levels in crops with poor, patchy stands (often the result of early season waterlogging) or where weeds had not been controlled.

Herbicide injury (Groups B, C, & I) was detected in most crops during Jun/Jul inspections including one striking example of damage predisposing a crop of PBA HatTrick at Billa Billa to PRR.  Overall, herbicides caused no serious yield loss.

Disease management recommendations for 2016

Seed treatment and seed purity

Seed borne Botrytis, seed borne Ascochyta and several soil borne fungi can cause pre- and post-emergence seedling death.   Irrespective of source of seed and year of production all chickpea planting seed should be treated with a registered seed dressing (Table 3).  Proper coverage of the seed with an adequate rate of product is essential.  Be confident of the identity and purity of your planting seed.  If unsure acquire certified seed from a reputable seed merchant.

Table 3. Chickpea seed treatments

Active ingredient

Example Product

Rate

Target disease

thiabendazole 200 g/L+ thiram 360 g/L

P-Pickel T®

200 mL/100 kg seed

Seed-borne Ascochyta, Botrytis, Damping off, Fusarium

thiram 600 g/L

Thiram 600

200 mL/100 kg seed

Seed-borne Botrytis and Ascochyta, Damping off

thiram 800 g/kg

Thiragranz®

150 g/100 kg seed

Seed-borne Botrytis and Ascochyta, Damping off

metalaxyl 350 g/L

Apron® XL 350 ES

75 mL/100 kg seed

Phytophthora root rot

Ascochyta blight

Recommendations for Ascochyta were revised in May 2016 

The following strategy should reduce losses from Ascochyta in 2016:

  • In areas where AB was detected in 2015, spray all varieties, including PBA HatTrick and PBA Boundary with a registered Ascochyta fungicide prior to the first rain event after crop emergence, three weeks after emergence, or at the 3 branch stage of crop development, whichever occurs first.
  • In areas where AB was NOT detected in 2015, spray all varieties with AB resistance lower than PBA HatTrick with a registered Ascochyta fungicide prior to the first rain event after crop emergence, three weeks after emergence, or at the 3 branch stage of crop development, whichever occurs first.
  • 2-3 weeks after each rain event, monitor all crops irrespective of variety and spray if Ascochyta is detected in the crop or is found in the district on any variety.
  • Ground application of fungicides is preferred. Select a nozzle such as a DG TwinJet or Turbo TwinJet that will produce no smaller than medium droplets (ASAE) and deliver the equivalent of 80–100 litres water/hectare at the desired speed.
  • Where aerial application is the only option (e.g. wet weather delays) ensure the aircraft is set up properly and that contractors have had their spray patterns tested.

Botrytis grey mould, BGM

In areas outside Central Queensland, spraying for BGM is not needed in most years.  However, if conditions favour the disease it will develop even though BGM was not a problem in 2015.   Thus, in situations favourable to the disease (high biomass, average daily temperature 15 oC or higher, overhead irrigation in spring), a preventative spray of a registered fungicide before canopy closure, followed by another application 2 weeks later will assist in minimising BGM development in most years.  If BGM is detected in a district or in an individual crop particularly during flowering or pod fill, a fungicide spray should be applied before the next rain event.  None of the fungicides currently registered or under permit for the management of BGM on chickpea have eradicant activity, so their application will not eradicate established infections. Consequently, timely and thorough applications are critical.

Phytophthora root rot

Phytophthora root rot is a soil and water-borne disease, the inoculum can become established in some paddocks.  Alternative Phytophthora hosts such as pasture legumes, particularly medics and lucerne must be managed to provide a clean break between chickpea crops. Damage is greatest in seasons with above average rainfall but only a single saturating rain event is needed for infection.  Avoid high-risk paddocks such as those with a history of Phytophthora in chickpea, water logging or pasture legumes, particularly medics and lucerne.  If considerations other than Phytophthora warrant sowing in a high-risk paddock, choose PBA HatTrick or Yorker and treat seed with metalaxyl.  Metalaxyl can be applied in the same operation as other seed dressings providing all conditions of permits and labels are met. Metalaxyl only provides protection for about 8 weeks; crops can still become infected and die later in the season.

Further information

GRDC Chickpea disease management factsheet

and in the NSW DPI 2016 Winter Crop Variety Sowing Guide.

Acknowledgements

This research is made possible by the significant contributions of growers through both trial cooperation, paddocks access and the support of the GRDC, the authors would like to thank them for their continued support. 

Contact details

Kevin Moore
Department of Primary Industries, Tamworth, NSW
Ph: 02 6763 1133
Mb: 0488 251 866
Fx: 02 6763 1100
Email: kevin.moore@dpi.nsw.gov.au

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GRDC Project code: DAN00176