Southern region pulse performance and agronomy update 2018
Southern region pulse performance and agronomy update 2018
Author: Jason Brand, Tim Nigussie (Agriculture Victoria) Christine Walela, Dili Mao, Andrew Ware (SARDI Clare) Jenny Davidson, Sara Blake, Rohan Kimber (SARDI Urrbrae) Garry Rosewarne (Agriculture Victoria) Josh Fanning, Jeff Paull (University of Adelaide). | Date: 20 Feb 2018
Take home messages
- The area sown to pulses in South Australia (SA) and Victoria (VIC) continued to increase, particularly lentils and chickpeas and in Mallee regions in response to highly profitable crops in 2016. Similar to previous seasons, the lentil variety, PBA Jumbo2 performed extremely well in 2017, highlighting its yield stability across a range of regions and through a range of seasonal conditions. It is a variety that reduces disease risks and benefits from sowing early to maximise yield potential.
- Delayed sowing in field trials generally resulted in significant yield losses in pulses in VIC across all sites and rainfall zones in 2017, with losses in gross margin ranging from $200/ha to $250/ha in lentils and $100to $600/ha in chickpeas. Significant varietal variation in response to sowing date was observed with losses in lentils greater than 50% from delayed sowing observed at Curyo. In field peas, early disease control with new fungicide actives is important for reducing initial ascochyta blight (AB) infection levels with a yield potential above 1.5t/ha. A late fungicide spray is important to control AB in spring when rainfall is conducive to disease spread and pod and seed infection. Early sowing into a high disease risk window with these improved new fungicide actives was demonstrated to have better yield benefits over later sowing in the 2017 season.
- Timely harvest is important for retaining grain quality attributes such as seed coat colour, seed coat wrinkling and screenings within the allowable maximum limit for total defective material and delivery of premium quality (grade 1) crops. Significant quality variation exists among genotypes in response to harvest time. Frost in 2017 caused significant yield and quality loss, with variation in quality noted among different varieties.
- Disease severity was low to moderate in pulses in 2017. Variety reactions to AB remain the same as previous seasons, although the pathotype of Ascochyta fabae, which is aggressive on Farah, is becoming more frequent and more widespread. AB lesions were observed on some PBA Hurricane XT lentil crops and AB was common in chickpea crops. Bacterial blight infected field peas in VIC following hailstorms and frosts. Root rot (potentially Phytophthora sp.) has caused significant yield losses in irrigated chickpea crops sown in late winter to spring in south eastern SA.
ɸ Extra technical comment by Protech Consulting Pty Ltd
2017 seasonal snapshot
The area sown to pulses in SA and VIC continued to increase in 2017 on the back of a record breaking 2016 season. Estimates indicate that more than 825,000ha was sown — a 5% increase on 2016 (ABARE Australian Crop Report, December 2017). Lentils and chickpeas drove most of this expansion, particularly in the low rainfall zone in response to high grain prices and highly profitable crops from the 2016 harvest.
In 2017, pulse grain yields were variable across the region, ranging from slightly above average to below average. For some regions, 2017 could be termed a ‘reality check’, after the excellent yields, prices and profitability observed in 2016. For example, in some lower rainfall zone areas, lentil yields were lower than 0.5t/ha combined with prices less than $500/ha. Despite the lower returns from pulses in some areas, we continue to see their value in the whole cropping system with higher yields in cereals observed following the pulse phase.
The environment, combined with a challenging period around sowing and having to control mice, played a crucial role in the variability of the pulse industry in 2017. For example, one of the Southern Pulse Agronomy (SPA) sites was baited 10 times to minimise crop damage. As a general observation in VIC, a majority of the early sown crops (late April to early May) were sown into a moist seed bed, ensuring good initial establishment, particularly following good summer rain. Crops sown from mid to late May were often sown into drying topsoil, which meant slow or staggered establishment. In contrast, sowing conditions were dry throughout most of SA, with some locations not experiencing significant rain events until late June.
Despite the challenging conditions, establishment and growth were generally adequate during the winter period which experienced average to above average rainfall. Annual growing season rainfall was generally close to long term averages in VIC and up to 15% below average in SA at SPA research sites. During late winter and early spring, several frost events resulted in crop damage, particularly in lentils, but there was also an outbreak of bacterial blight in field peas in some regions. Generally, disease levels in pulses were low and well managed, due to dry spring conditions. Drying spring conditions, combined with high temperatures in some of the lower rainfall zones, contributed to lower yields in lower rainfall zones. High winds, just after maturity, also caused significant losses in lentils throughout many regions. A late spring frost throughout parts of the medium rainfall zone (Wimmera) caused significant yield and grain quality loss in lentils and chickpeas.
New variety release
Field peas
PBA Butler (tested as OZP1101) is a superior yielding ‘Kaspa type’ field pea. It is distinctly more vigorous than popular semi-leafless pea varieties such as Kaspa, PBA Oura and PBA Gunyah. PBA Butler combines resistance to the economically important diseases, bacterial blight and downy mildew. Although it is rated as moderately susceptible to black spot, it is one of the better performing field peas in this regard. PBA Butler has a broad adaptation and it is suitable to grow across all field pea production zones in southern Australia. PBA Butler has significant advantages in regions prone to bacterial blight and downy mildew.
Agronomic research highlights
SPA is a collaborative agronomic research program with investment by GRDC, DEDJTR and SARDI, with agronomic trials across SA and VIC. Some key findings from 2017 are highlighted here and previous research related to key research areas of herbicide tolerance, disease management, canopy management (biomass and architecture) and harvest quality. Further research and details relating to agronomy and new varieties will be discussed during the updates. A complete summary of trials will be available later in 2018.
Herbicide tolerance
SPA has been evaluating an elite Plant Breeding Australia (PBA) faba bean breeding line incorporating Group B tolerance traits (developed through project DAS00131), in parallel to the Group B tolerant lentil variety PBA Hurricane XT, in a range of agronomic trials over the past few years with promising results. DAS00131, along with project DAS00113, has also explored a range of other traits in lentils, including group C tolerance, and more recently has started trait development work in chickpeas and field peas. However, extensive characterisation, genetic understanding, and evaluation of the commercial potential of all these traits are still required to deliver all of these traits to market. DAS00131 is also working closely with PBA to rapidly incorporate any useful tolerance traits into elite backgrounds, and once validated, the best of these lines will be evaluated more broadly across a range of agronomic trials to ensure best management packages are available to growers for potential new varieties which incorporate herbicide tolerance traits.
Sowing dates
A range of higher yielding pulse varieties have been released with improvements in agronomic traits including biomass production, lodging resistance, disease resistance, herbicide tolerance, maturity and pod retention. In addition, growers are sowing crops earlier to maximise yield potential and reduce risks of heat and terminal drought stress. Research in 2017, similar to 2016, focused on understanding the variability in varieties and breeding lines in response to sowing dates.
At all trial sites and for all crops assessed, there was a reduction in yields from delayed sowing ranging from 2% to 37% (Table 1). For chickpeas at Curyo, this equated to a reduction in a gross margin of more than $500/ha (up to $900/ha in kabulis). The magnitude of response was related to a number of environmental factors including moisture at sowing, and timing of frost and heat events. Due to the relatively dry spring conditions and active management, disease was not an issue in all trials in 2017 except field peas at Rupanyup, where bacterial blight was observed at low levels following frost in early spring. As indicated previously, in VIC moisture was generally optimal at the earlier ‘standard’ sowing date and drier at the delayed sowing. This, combined with the warmer air and soil temperatures, meant that the establishment and early growth of the earlier sown treatments were much more vigorous and advanced than the delayed treatments.
For much of the season, growth of the earlier ‘standard’ treatments was approximately four to six nodes ahead of the delayed treatments for all crops. The differential growth stages associated with sowing dates meant that the impact of frost was variable across both crops and varieties (discussed in Table 2). For example, in field peas at Rupanyup, frosts during spring, which contributed to bacterial blight, and then in early November, are likely to have more significantly impacted on the earlier ‘standard’ sowing date in comparison to delayed sowing (Table 1). No major frosts had an impact on the crops at Ouyen and Curyo, but heat and drying conditions during spring are likely to have significantly impacted the delayed sowing plots, generally resulting in substantially lower yields. For chickpeas there was only a 9% reduction in yield from delayed sowing at Ouyen, but 28% and 17% reductions were observed at Curyo and Rupanyup, respectively (Table 1). The relatively low reduction observed at Ouyen is likely related to the poor ability of chickpeas to set pods at low temperatures (below 15OC mean daily average).
The treatments sown earliest were flowering during colder temperatures, therefore pod set was poor. As temperatures increased, soil moisture also became limiting, therefore both the standard and delayed sowing date treatments set pods during the same period. Further work is ongoing within PBA looking for traits enabling chickpeas to set pods at cooler temperatures. In 2017, many of these lines flowered much earlier than current varieties and breeding lines in the trials, but did not appear to set pods any earlier (data not shown).
In 2018, growers are encouraged to continue sowing pulses in the optimal sowing window. Avoid delayed sowing unless there is a strategic management advantage related to disease or weed control or if they are being sown in a frost prone region. In the long term, from a VIC perspective, early sowing has generally proved profitable, as heat events and rapidly drying soil during late spring in the flowering and podding phase occur almost every year and cause significant yield losses to delayed sowing. Further discussion and SA results will be provided at the updates.
Table 1. Mean grain yield (t/ha) of pulse crops (across all varieties) sown at standard sowing dates in comparison with delayed sowing at VIC SPA trials sites in 2017. Ouyen – central Mallee, Curyo – southern Mallee, Rupanyup – Wimmera, Streatham – south west.
Site (Rainfall zone) | Sowing date | Lentils | Chickpeas | Field peas | Faba beans |
---|---|---|---|---|---|
Ouyen (LRZ) | Standard (10 May) | 1.04 | 1.14 | 1.99 | - |
Delayed (31 May) | 0.66 | 1.04 | 1.45 | - | |
% Yield loss | 37 | 9 | 27 | - | |
Curyo (LRZ) | Standard (9 May) | 2.33 | 2.30 | 3.10 | - |
Delayed (7 June) | 1.90 | 1.65 | 1.98 | - | |
% Yield loss | 18 | 28 | 36 | - | |
Rupanyup (MRZ) | Standard (10 May) | 3.35 | 2.80 | 3.10 | 4.26 |
Delayed (16 June) | 2.73 | 2.32 | 3.05 | 3.88 | |
% Yield loss | 19 | 17 | 2 | 9 | |
Streatham (HRZ) | Standard (3 May) | - | - | - | 4.24 |
Delayed (2 June) | - | - | - | 3.22 | |
% Yield loss | - | - | - | 24 |
There was also a significant variation in the response of varieties to sowing dates across the various trial sites. Results in Table 2 highlight trends for lentils in 2017, although similar observations were seen in other crops investigated (data not shown). Grain yields for lentils were generally less than in 2016, but still profitable based on gross margin, ranging between 0.50t/ha to 1.39t/ha at Ouyen, 1.47t/ha and 2.80t/ha at Curyo and 2.21t/ha and 3.92t/ha at Rupanyup. Overall, PBA Jumbo2 was the highest yielding commercial variety, equivalent to the highest yielding lines, continuing to highlight its yield stability across a range of regions and seasons.
PBA Flash was the lowest yielding commercial variety, while PBA Hurricane XT performed relatively poorly, reflective of industry observations in 2017. It was noted in industry that throughout many regions, PBA Hurricane XT appeared to show more visual symptoms from Group C herbicides in early growth and then from frost damage during vegetative growth (pale and burnt upper leaves). Both of these factors could have contributed to the relative lower yields observed in industry during 2017, however it is important to note that long term trial yields have always indicated approximately 10% lower yield of PBA Hurricane XT relative to the latest conventional varieties, such as PBA Jumbo2.
Average yield losses from delayed sowing were 37% at Ouyen and 18% at Curyo and Rupanyup, however within each site, losses varied significantly across variety (1% to 55% at Ouyen, 3% to 38% at Curyo and -11% to 32% at Rupanyup — Table 2). There did not appear to be a clear link with phenology (flowering and maturity). For example, both CIPAL1504 (mid to late) and CIPAL1523 (early) showed yield losses of 28% and 33%, respectively, averaged across sites. While some varieties/breeding lines showed relatively consistent yield losses across sites, for example, PBA Ace and CIPAL1422, others, such as CIPAL1601 and CIPAL1621 varied greatly. The potential reasons for these responses and implications for breeding and agronomy are currently being investigated.
Table 2. Grain yield (t/ha) of lentil varieties and breeding lines sown at standard sowing dates in comparison with delayed sowing at VIC SPA trial sites in 2017.(Varieties and breeding lines ranked based on mean average yield across all sites. Shades relate to relative yield within a sowing date at one site).
Variety | Ouyen | Curyo | Rupanyup | |||
---|---|---|---|---|---|---|
May 10 | May 31 | May 09 | June 07 | May 18 | June 16 | |
CIPAL1522 | 1.17 | 0.68 | 2.63 | 2.16 | 3.59 | 3.07 |
CIPAL1504 | 1.39 | 0.78 | 2.80 | 1.74 | 3.38 | 2.90 |
PBA Jumbo2 | 1.20 | 0.68 | 2.55 | 1.75 | 3.52 | 3.12 |
CIPAL1301 | 1.04 | 0.55 | 2.51 | 1.95 | 3.65 | 3.08 |
CIPAL1721 | 0.93 | 0.92 | 2.49 | 1.91 | 3.55 | 2.97 |
CIPAL1701 | 1.15 | 0.56 | 2.58 | 1.99 | 3.36 | 3.04 |
L1 | 1.30 | 0.62 | 1.97 | 1.86 | 3.92 | 2.98 |
PBA Ace | 1.00 | 0.80 | 2.53 | 2.28 | 3.14 | 2.68 |
PBA Bolt | 0.92 | 0.67 | 2.33 | 2.15 | 3.41 | 2.90 |
CIPAL1521 | 1.02 | 0.63 | 2.56 | 1.96 | 3.44 | 2.54 |
CIPAL1601 | 1.10 | 0.50 | 2.18 | 2.08 | 3.37 | 2.62 |
PBA Jumbo | 1.06 | 0.82 | 2.33 | 2.12 | 3.05 | 2.47 |
CIPAL1602 | 0.87 | 0.64 | 2.12 | 1.73 | 3.52 | 2.69 |
CIPAL1621 | 1.00 | 0.56 | 1.98 | 1.86 | 3.59 | 2.57 |
PBA Greenfield | 0.91 | 0.65 | 2.26 | 1.77 | 3.06 | 2.79 |
CIPAL1422 | 1.00 | 0.78 | 2.27 | 1.84 | 3.14 | 2.40 |
PBA Hurricane XT | 0.87 | 0.65 | 2.09 | 1.75 | 3.60 | 2.44 |
PBA Giant | 1.04 | 0.54 | 2.09 | 2.02 | 3.00 | 2.42 |
CIPAL1523 | 0.95 | 0.51 | 2.08 | 1.47 | 3.20 | 2.21 |
PBA Flash | 0.87 | 0.66 | 2.20 | 1.58 | 2.41 | 2.67 |
Average | 1.04 | 0.66 | 2.33 | 1.90 | 3.35 | 2.73 |
LSD (P<0.05) | ||||||
TOS x Variety | 0.27 | NS | NS | |||
TOS | 0.26 | 0.34 | 0.53 | |||
Variety | 0.19 | 0.37 | 0.35 |
Variety | Cross Site Average | ||
---|---|---|---|
Standard | Delayed | Mean | |
CIPAL1522 | 2.46 | 1.97 | 2.22 |
CIPAL1504 | 2.52 | 1.81 | 2.17 |
PBA Jumbo2 | 2.42 | 1.85 | 2.14 |
CIPAL1301 | 2.40 | 1.86 | 2.13 |
CIPAL1721 | 2.32 | 1.93 | 2.13 |
CIPAL1701 | 2.36 | 1.86 | 2.11 |
L1 | 2.40 | 1.82 | 2.11 |
PBA Ace | 2.22 | 1.92 | 2.07 |
PBA Bolt | 2.22 | 1.91 | 2.06 |
CIPAL1521 | 2.34 | 1.71 | 2.03 |
CIPAL1601 | 2.22 | 1.73 | 1.98 |
PBA Jumbo | 2.15 | 1.80 | 1.98 |
CIPAL1602 | 2.17 | 1.69 | 1.93 |
CIPAL1621 | 2.19 | 1.66 | 1.93 |
PBA Greenfield | 2.08 | 1.74 | 1.91 |
CIPAL1422 | 2.14 | 1.67 | 1.91 |
PBA Hurricane XT | 2.19 | 1.61 | 1.90 |
PBA Giant | 2.04 | 1.66 | 1.85 |
CIPAL1523 | 2.08 | 1.40 | 1.74 |
PBA Flash | 1.83 | 1.64 | 1.73 |
Average | 2.24 | 1.76 | 2.00 |
Note: Cross site data still to be analysed at time of writing.
Disease management in field peas
Multi-year evaluation of the efficacy and yield benefit of new foliar fungicides for control of AB in field peas
Recently, new fungicide actives have emerged in the market, offering superior disease control in field crops. However, they have not been tested for AB control in field peas and are not registered for that use. As part of continuing research, experimental field studies have been undertaken to evaluate the efficacy of new actives in disease control and yield benefits in low (Minnipa, upper Eyre Peninsula) and medium (Hart, Mid-North) rainfall zones in SA. The trials undertaken by SARDI are part of the SPA project funded by the Grains Research and Development Corporation (GRDC) (DAV00150). The performance of two new actives constituting a) bixafen (75g/L) in combination with prothioconazole (150g/L) retailed as Aviator Xpro®, and b) azoxystrobin (200g/L) in combination with cyproconazole (80g/L) trading as Amistar Xtra® were compared to, mancozeb (2kg/ha), seed treatment P Pickle T®, fortnightly chlorothalonil treatment (complete disease control) and an untreated (Nil) treatment. Experimental field trials were conducted from 2015 to 2017.
In 2015, trials compared the new actives against the industry standard practice of a seed dressing plus two mancozeb sprays at nine weeks after sowing (WAS) and early flowering. In 2016, trials included an earlier spray at the four node to six node growth stage, when disease was first sighted. In 2017, two times of sowing were included to produce high and low disease risk with fungicide treatments as per 2016 at Hart only.
In all years, disease severity was assessed at vegetative and flowering growth stages. Grain yield was recorded at maturity. Notably, only selected treatments have been presented in this report.
Results
Effect of fungicide treatments on disease severity
Disease onset occurred earlier in the low rainfall zone compared to the medium rainfall zone, indicating the drivers of AB onset were different across the two environments (Table 3). Subsequently, results showed AB response to fungicide treatment changes depending on environmental conditions.
Mancozeb applications reduced AB severity compared to the Nil treatment at Hart in 2015 and 2016, while there was no reduction in 2017. In contrast, AB severity was not reduced at Minnipa, where severity was initially higher. This may be due to the establishment of the disease prior to the first foliar applications nine WAS weeks after sowing.
Amistar Xtra® reduced disease infection levels at Hart in 2015, but not in 2016 nor in either year at Minnipa. In 2017, disease severity in Amistar Xtra® was similar to mancozeb and the two Aviator Xpro® treatments, but lower than the Nil treatment.
Aviator Xpro® sprayed at six WAS to eight WAS, plus early flowering, reduced disease severity over the Nil treatment at Hart and Minnipa in 2015. The strategy of including an early spray of Aviator Xpro® at 4 WAS, followed by a second application at 9 WAS and mancozeb at early flowering resulted in lower disease severity at both Hart and Minnipa, compared to treatments other than fortnightly sprays of chlorothalonil in 2016. There was no fungicide interaction with sowing date in 2017, with the fungicide effect similar across sowing dates. The application of two Aviator Xpro® treatments showed similar higher disease control to the Amistar Xtra® treatment, compared to the mancozeb and Nil treatments.
Table 3. AB disease severity (% plot severity) assessed at between 9 node and 13 node growth stage in field peas (PBA Coogee) under different fungicide treatments at Hart (Mid-North, SA) and Minnipa (upper Eyre Peninsula, SA) 2015 to 2017.
Year | Fungicide treatment | Application timing | Disease severity (%) | |
---|---|---|---|---|
Hart | Minnipa | |||
2015 | Nil | N/A | 24 | 37 |
P Pickle T® | Seed treatment | 28 | 27 | |
Mancozeb | 8 WAS + Early flowering | 12 | 30 | |
Amistar Xtra® | 8 WAS + Early flowering | 6 | 30 | |
Aviator Xpro® | 8 WAS + Early flowering | 4 | 23 | |
Chlorothalonil | Fortnightly | 9 | 18 | |
Lsd (P<0.05) Fungicide x site | 8 | |||
2016 | Nil | N/A | 32 | 51 |
P Pickle T® | Seed treatment | 36 | 46 | |
Mancozeb | 6 WAS + Early flowering | 24 | 47 | |
Amistar Xtra® | 6 WAS + Early flowering | 33 | 49 | |
Aviator Xpro® | 6 WAS + Early flowering | 24 | 46 | |
Aviator Xpro® + mancozeb | 4 WAS, 9 WAS + mancozeb at early flowering | 17 | 42 | |
Chlorothalonil | Fortnightly | 14 | 25 | |
Lsd (P<0.05) Fungicide x site | 7.8 | |||
2017 | Nil | N/A | 55 | - |
Mancozeb | Early disease + Early flowering | 48 | - | |
Amistar Xtra® | Early disease + Early flowering | 42 | - | |
Aviator Xpro® | Early disease + Early flowering | 39 | - | |
Aviator Xpro® + mancozeb | Early disease + Early flowering + mancozeb mid-flowering | 37 | - | |
Chlorothalonil | Fortnightly | 2 | - | |
Lsd (P<0.05) Fungicide | 8.1 |
Note: WAS = weeks after sowing. NB: Fungicide application rates have been withheld. Notably, in 2017, a trial was not conducted at Minnipa due to the late break of the season.
Effect of fungicide treatments on grain yield
The mean site grain yield was 1.6t/ha in 2015 for both Hart and Minnipa, with higher yields at Hart (1.74t/ha) than at Minnipa (1.30t/ha) in 2016 (Table 4). In 2017, the first time of sowing (27 April) yielded 3.1t/ha with the second time of sowing (31 May) 2.3t/ha (Table 5). Fungicide strategies in field peas are generally economic for yields above 1.5t/ha.
Grain yields showed a similar fungicide treatment response across the two sites in 2015. In 2016, a significant fungicide treatment by site interaction was found for grain yield. Across all trials the highest yields were associated with Aviator Xpro®, Amistar Xtra® and fortnightly sprays of chlorothalonil, while mancozeb sprays did not significantly increase yield over Nil treatments in any of the trials (Table 4).
In 2017, the three spray application strategy of Aviator Xpro® at early disease sighting plus early flowering and a late spray of mancozeb at mid-flowering produced yields similar to fortnightly chlorothalonil (Table 4). In contrast, this response was not found in 2016, where fortnightly chlorothalonil had higher yields than the three spray strategy. This may be due to the number of chlorothalonil sprays being applied in seasons with more favourable and wetter finishing conditions. Although 2017 was generally drier, a substantial amount of rain fell in late winter to early spring. The late spray of mancozeb in the Aviator Xpro® treatment was beneficial in controlling the spread of AB, resulting in yield increases in early sown crops, similar to the fortnightly chlorothalonil treatment.
Grain yields increased by up to 20% from the use of new actives over the current industry standard in the early sown plots at Hart in 2017. In the later sowing, there was no yield response to fungicides. This result shows that significant yield penalties can occur if field pea crops are sown later or in high disease risk situations, such as early sowing, where fungicides are not applied.
Table 4. Mean grain yields (t/ha) of field peas (PBA Coogee) sown with different fungicide treatments at Hart (Mid-North, SA) and Minnipa (Eyre Peninsula, SA) in 2015 and 2016.
Year | Fungicide Treatment and Rate (gai/ha) | Application Timing | Grain Yield (t/ha) | |
---|---|---|---|---|
Hart and Minnipa | ||||
2015 | Nil | - | 1.55 | |
P Pickle T® | Seed treatment | 1.47 | ||
Mancozeb | 8 WAS and Early flowering | 1.47 | ||
Amistar Xtra® | 8 WAS and Early flowering | 1.77 | ||
Aviator Xpro® | 8 WAS and Early flowering | 1.79 | ||
Chlorothalonil | Fortnightly | 1.73 | ||
Lsd (P<0.05) Fungicide | 0.16 | |||
Hart | Minnipa | |||
2016 | Nil | - | 1.49 | 0.95 |
P Pickle T® | Seed treatment | 1.33 | 1.05 | |
Mancozeb | 6 WAS + Early flowering | 1.54 | 1.19 | |
Amistar Xtra® | 6 WAS + Early flowering | 1.84 | 1.32 | |
Aviator Xpro® | 6 WAS + Early flowering | 1.93 | 1.4 | |
Aviator Xpro® + mancozeb | 4 WAS, 9 WAS + Early flowering | 1.65 | 1.58 | |
Chlorothalonil | Fortnightly | 2.67 | 1.67 | |
Lsd (P<0.05) Fungicide X Site | 0.34 |
In 2017, severe frost events occurred, coinciding with the critical development period of pod filling in early sown crops at the Hart site. The frost damage impacted the grain quality of early sown crops, whereby more seeds had a shrunken and discoloured appearance on the seed coat (Figure 1). This suggests that site selection is important when early sowing crops in order to avoid a frost event during critical growth and development periods. Growers may need to adjust the sowing window of early sown crops depending on the history of frost events in the district.
In conclusion, early disease control with new fungicide actives is important for reducing initial AB infection levels. In addition, a late fungicide spray is important to control AB in spring when rainfall is conducive to disease spread and pod and seed infection. In situations with yield potentials above 1.5t/ha, the new fungicides showed improved disease control and a yield benefit of 15% to 20% over the current industry standard. Early sowing into a high disease risk window with these improved new fungicide actives was demonstrated to have improved yield benefits over later sowing in the 2017 season. The results, however, need to be interpreted with caution as disease pressure was low and progression was reduced by below average rainfall in 2017. The susceptibility of early sown field peas to frost events will also require consideration. Further research is being undertaken to understand the drivers of AB in the different environments.
Table 5. Mean grain yields (t/ha) of field peas (PBA Oura) at different sowing dates under varying AB disease risk levels and different fungicide treatments at Hart (Mid-North, SA) in 2017.
Fungicide treatment | Grain yield (t/ha) | Grain weights (g/100 seed) | ||
---|---|---|---|---|
27-April | 31-May | 27-April | 31-May | |
Chlorothalonil | 3.53a | 2.29a | 22.99a | 22.11a |
Aviator Xpro® and mancozeb | 3.42a | 2.19a | 22.15b | 22.51a |
Aviator Xpro® | 3.22b | 2.33a | 22.00b | 22.46a |
Amistar Xtra® | 3.04b | 2.37a | 21.21c | 22.57a |
Mancozeb | 2.76c | 2.31a | 20.87cd | 22.57a |
Nil | 2.66c | 2.28a | 20.65d | 22.35a |
Lsd (P<0.05) Fungicide x Sowing time | 0.19 | 0.19 | 0.47 | 0.47 |
NB: Seed dressing of P Pickle T® was used at sowing in all treatments except the Nil treatment.
Figure 1. Frost damage expressed as shrunken and discoloured seed coat in field peas (PBA Oura) sown at different sowing dates under varying AB disease risk levels and different fungicide treatments at Hart (Mid-North, SA) in 2017.
Grain quality and harvest timing
Generally, little is understood about the impact of adverse weather events on mature pulse crops, yet major quality and industry issues have arisen when they have occurred in the past. Genetic and agronomic differences have been reported as being important in reducing quality losses. SPA has undertaken opportunistic research in 2016 and 2017 through trials assessing delayed harvest and weather events on a range of genotypes. Selected results from the 2016 season are presented here, showing delayed harvest significantly impacted on grain quality. Assessments are currently also occurring from the 2017 season, including the impact of frost, with some data likely to be available for the update presentations.
In 2016, trials in SA investigated the impact of harvest timing (delayed harvest and climatic events) on seed quality (grain weight, seed coat colour, seed coat wrinkling and screenings) of different pulse crops. Harvest time 1 was considered as the control and was harvested post physiological maturity, approximately 10 days after crop desiccation. The crops were then exposed to significant weather (rainfall) events prior to conducting subsequent latter harvests. Grain quality was assessed for common defects including poor seed coat colour (discolouration), wrinkles, screenings (splits and cracks), and grain weight. The results related to lentils are highlighted here, with full details of all crops and treatments available in the 2016 Southern Pulse Agronomy Annual Result Summary.
For lentils, there was a significant interaction between variety and harvest timing observed for screenings, seed coat colour and wrinkles indicating that lentil varieties were affected differently in these grain quality attributes depending on harvest timing. All varieties had screenings of less than 1 % at the initial harvest timing of 10 days after reaching physiological maturity, with screenings gradually increasing as harvesting was delayed.
Harvesting one month and almost two months after physiological maturity led to a rapid increase in screenings in the early maturing lentil variety, PBA Blitz and two green lentils, PBA Giant and PBA Greenfield compared to other varieties (Table 6). This indicated that the three varieties were more sensitive to damage in this defect by delaying harvest. Varietal differences in seed weight were characteristic of the inherent differences between varieties in this grain quality attribute. Seed weight of some varieties such as PBA Blitz, PBA Giant and PBA Greenfield tended to decrease more compared to other varieties as harvest was delayed (data not shown). All varieties maintained seed coat colour within the maximum allowable limit of less than 1% for grade 1 lentils at a timely harvest of 10 days post physiological maturity (Table 7).
Data from one season showed that only three varieties, Nugget, PBA Flash and PBA Hurricane XT maintained seed coat colour of less than 1%, for grade 1 lentils, when harvested a month post physiological maturity. All other varieties had started to discolour at this timing, deliverable only as grade 2 except for PBA Giant whose colour was more than 3.0% above the allowable maximum limit for this grade. Late harvesting at almost two months post physiological maturity caused significant discoloration of seed coat colour in all varieties (>10%), which was beyond delivery of grade 1 and 2 lentils.
The length in period of exposure to environmental effects was a major factor influencing the loss of seed coat colour across all varieties. Varieties such as Nugget, PBA Blitz, PBA Giant, PBA Greenfield and PBA Jumbo 2 had wrinkled seed coat levels more than 1% by the first harvest time of 10 days post physiological maturity. At this harvest timing, the site had already received 17mm of rainfall post physiological maturity, indicating that these varieties were more sensitive to wrinkle damage from rainfall. Subsequent delays in harvesting caused significant seed coat wrinkling across all varieties indicating that rainfall was a significant factor in causing this defect (Table 8).
Table 6. Screenings (% by weight) in 12 lentil varieties, averaged across three different harvest timings at Turretfield, SA, 2016.
Variety | Harvest time 1 | Harvest time 2 | Harvest time 3 | |||
---|---|---|---|---|---|---|
SQRT | Raw data | SQRT | Raw data | SQRT | Raw data | |
CIPAL1301 | 0.70 | 0.49 | 1.88 | 3.54 | 2.84 | 8.04 |
CIPAL1422 | 0.79 | 0.62 | 1.92 | 3.70 | 2.80 | 7.85 |
Nipper | 0.84 | 0.71 | 1.37 | 1.87 | 1.75 | 3.07 |
Nugget | 0.75 | 0.56 | 1.93 | 3.71 | 2.91 | 8.49 |
PBA Ace | 0.69 | 0.48 | 2.17 | 4.70 | 3.00 | 9.00 |
PBA Blitz | 1.21 | 1.46 | 3.23 | 10.43 | 4.35 | 18.88 |
PBA Bolt | 0.82 | 0.67 | 1.98 | 3.91 | 2.97 | 8.84 |
PBA Flash | 0.88 | 0.77 | 1.75 | 3.07 | 2.88 | 8.27 |
PBA Giant | 0.97 | 0.94 | 3.63 | 13.18 | 4.87 | 23.72 |
PBA Greenfield | 0.61 | 0.37 | 2.50 | 6.25 | 3.67 | 13.49 |
PBA Hurricane XT | 0.71 | 0.51 | 1.51 | 2.29 | 2.33 | 5.42 |
PBA Jumbo 2 | 0.94 | 0.87 | 1.76 | 3.11 | 2.64 | 6.97 |
LSD | 0.52 | 0.52 | 0.52 |
Table 7. Poor seed colour (% by weight) in 12 lentil varieties, averaged across three different harvest timings at Turretfield, SA, 2016.
Variety | Poor seed coat colour (% by weight) | |||||
---|---|---|---|---|---|---|
Harvest time 1 | Harvest time 2 | Harvest time 3 | ||||
SQRT | Raw data | SQRT | Raw data | SQRT | Raw data | |
CIPAL1301 | 1.2 | 0.2 | 2.7 | 1.4 | 9.7 | 18.8 |
CIPAL1422 | 0.7 | 0.0 | 2.9 | 1.6 | 13.0 | 34.0 |
Nipper | 0.6 | 0 | 3.2 | 2.0 | 5.9 | 7.0 |
Nugget | 0.5 | 0 | 1.5 | 0.4 | 10.0 | 20.0 |
PBA Ace | 0.4 | 0 | 2.5 | 1.2 | 7.9 | 12.6 |
PBA Blitz | 1.4 | 0.4 | 2.8 | 1.6 | 15.7 | 49.0 |
PBA Bolt | 0.5 | 0 | 2.9 | 1.8 | 11.9 | 28.2 |
PBA Flash | 0.3 | 0 | 2.0 | 0.8 | 10.5 | 22.0 |
PBA Giant | 2.0 | 0.8 | 4.8 | 4.6 | 12.5 | 31.2 |
PBA Greenfield | 1.6 | 0.4 | 3.9 | 3.0 | 13.8 | 38.0 |
PBA Hurricane XT | 0.8 | 0.2 | 1.9 | 0.8 | 9.5 | 18.2 |
PBA Jumbo 2 | 1.2 | 0.2 | 2.5 | 1.2 | 9.8 | 19.2 |
LSD | 1.62 | 1.62 | 1.62 |
Table 8. Seed coat wrinkling (% by weight) in 12 lentil varieties, averaged across three different harvest timings at Turretfield, SA, 2016.
Variety | Wrinkling (% by weight) | |||||
---|---|---|---|---|---|---|
Harvest time 1 | Harvest time 2 | Harvest time 3 | ||||
SQRT | Raw data | SQRT | Raw data | SQRT | Raw data | |
CIPAL1301 | 1.7 | 0.6 | 8.4 | 14.2 | 9.7 | 18.8 |
CIPAL1422 | 1.6 | 0.6 | 8.4 | 14.2 | 10.4 | 21.6 |
Nipper | 1.4 | 0.4 | 6.5 | 8.4 | 5.3 | 5.8 |
Nugget | 3.5 | 2.4 | 10.7 | 23 | 9.9 | 19.8 |
PBA Ace | 1.6 | 0.6 | 7.0 | 9.8 | 9.2 | 17 |
PBA Blitz | 3.8 | 3.0 | 12.2 | 29.6 | 11.4 | 26 |
PBA Bolt | 1.3 | 0.4 | 7.9 | 12.4 | 10.9 | 23.8 |
PBA Flash | 2.1 | 0.8 | 9.9 | 19.8 | 7.0 | 9.8 |
PBA Giant | 4.2 | 3.4 | 12.3 | 30.4 | 9.3 | 17.2 |
PBA Greenfield | 2.4 | 1.2 | 14.1 | 39.6 | 12.1 | 29.7 |
PBA Hurricane XT | 1.3 | 0.4 | 6.4 | 8.2 | 10.9 | 23.6 |
PBA Jumbo 2 | 2.6 | 1.4 | 6.4 | 8.2 | 7.5 | 11.4 |
LSD | 2.52 | 2.52 | 2.52 |
In conclusion, timely harvest within the optimum window of 10 days post physiological maturity was important for retaining grain quality attributes such as seed coat colour, seed coat wrinkling and screenings within the allowable maximum limit for total defective material and delivery of premium quality (grade 1) crops. A delay in harvest post this window, coupled with exposure to environmental elements, including significant rainfall events and long periods of exposure to sunlight, had a significant and negative effect on grain quality which led to subsequent downgrading across all crops. In lentils, the amount of seed with poor seed coat colour and screenings increased as the period between post physiological maturity and harvesting was increased. Some varieties, PBA Blitz, and green lentil types PBA Giant and PBA Greenfield, were found to have an increased level of screenings and discoloration as harvest timing was delayed.
There was a rapid increase in seed coat wrinkling across all lentil varieties as the amount of rainfall increased post the optimum harvest window. This indicated that exposure to significant amounts of rainfall was an important environmental driver of this quality parameter. Good rainfall conditions during the growing season and springtime led to increased crop growth and lengthened the grain filling period by approximately one month across all crops. Rainfall continued well after crops had reached physiological maturity. Managing harvest under such conditions was important in the delivery of quality. Our results show that a delay in harvesting increased quality defects above the allowable maximum limit and some varieties were more sensitive to others in respective crops. However, it is worth noting that the data provided constitutes data from one season and therefore should be interpreted with care. The current research is ongoing and further results will be provided in the coming season.
Pulse pathology 2017
AB in faba beans
Forty isolates of A. fabae collected in 2016 from faba bean field trials and commercial paddocks in SA and VIC were tested on a differential host set that included Australian commercial varieties. Faba bean varieties have not changed reactions to AB since 2015 (Table 9) and screening of the isolates identified three reaction groups. Farah is moderately susceptible to AB in the Lower to Upper North of SA, PBA Rana and PBA Zahra are partially compromised, while PBA Samira and Nura remain resistant. These new pathotypes are also becoming established in the Yorke Peninsula, South East and Wimmera growing regions. A three spray fungicide strategy is now required to control AB in Farah, while podding sprays should be planned for PBA Rana and PBA Zahra to prevent pod and seed infection.
Table 9. Reactions of a number of faba bean varieties to Aschochyta blight.
Test reaction | Icarus (susceptible check) | Farah | Nura AR | Rana | Samira | Zahra |
---|---|---|---|---|---|---|
R | 0 | 1 | 40 | 0 | 20 | 1 |
MR | 0 | 1 | 0 | 11 | 12 | 8 |
MRMS | 0 | 7 | 0 | 13 | 7 | 23 |
MS | 0 | 23 | 0 | 15 | 1 | 8 |
S | 40 | 8 | 0 | 1 | 0 | 0 |
There were several reports of AB in PBA Samira, however, it is important to remember that even resistant rated pulses may get some lesions. Testing conducted at SARDI has found that PBA Samira remains resistant to AB and the few reports of infection most likely reflect genetic drift from outcrossing, which has partially compromised resistance in some grower retained seed.
AB in lentils
Thirty eight isolates of A. lentis collected in 2016 from lentil field trials and commercial paddocks in SA and VIC were tested on a differential host set that included PBA Hurricane XT and Nipper (Table 10). Lentil varieties have not changed reactions to AB since 2015. However, very few isolates were able to infect Nipper, in contrast to previous seasons when the frequency of Nipper virulent isolates was high. This drop is presumably in response to the low cropping frequency of Nipper so there is no selection pressure for this type of isolate. Lesions have been observed on PBA Hurricane XT crops, but in controlled environment tests, no isolates were highly virulent on PBA Hurricane XT. Resistant parents ILL7537 and Indianhead were resistant to most isolates, although a small number of isolates could infect Indianhead, a common source of resistance in the Australian lentil breeding program.
Table 10. Reactions of a number of lentil varieties to Aschochyta blight.
Test reaction | Cumra (susceptible check) | Nipper | PBA Hurricane XT | ILL7537 (resistant line) | Indianhead (resistant line) |
---|---|---|---|---|---|
R | 1 | 18 | 25 | 38 | 29 |
MR | 7 | 20 | 13 | 0 | 5 |
MRMS | 16 | 0 | 0 | 0 | 2 |
MS | 9 | 0 | 0 | 0 | 2 |
S | 5 | 0 | 0 | 0 | 0 |
AB collections
Growers and agronomists are asked to monitor their pulse crops for development of AB. Sara Blake, Research Officer at SARDI, is seeking assistance in collecting diseased samples from commercial crops as part of GRDC-funded research (CUR00023) monitoring AB pathogen populations and any changes in variety resistance. If ascochyta lesions are seen, please contact SARDI in SA — Sara Blake via email or phone on 08 8303 9383 for a collection envelope and return post envelope.
Agriculture Victoria — Cropsafe, Private Bag 260, Horsham, Vic 3401, 08 5362 2111.
Bacterial blight in field peas
Bacterial blight in field peas was detected across the Mallee and Wimmera regions following hail storms, frost or radiating from wheel tracks. Unfortunately, there is nothing that can be done to protect an infected crop or help it recover. The main recommendation is to stay out of the crop to prevent the disease being spread further on tyres or on boots. Infected crops should be the last field pea crops to be harvested. This is to prevent the trash from infecting field pea grain of non-infected crops. No grain should be kept from infected crops as there is a high chance of seed infection. If a crop has only a small area infected, then it is possible to harvest a clean area for seed.
When planning to sow field pea crops, growers need to consider that if a paddock is frost prone, it is best to sow field peas into a fallow rather than retaining the stubble. This is because the stubble increases the risk of frost, which in turn increases the risk of bacterial blight. The preferred field pea varieties to grow in frost prone areas are PBA Oura or PBA Percy, which are less susceptible to bacterial blight than other varieties.
Further information on bacterial blight
Soil-borne diseases
First time, provisional ratings for the root lesion nematode, Pratylenchus neglectus, have been released for chickpeas and faba beans. These ratings add to the current ratings provided, allowing growers to manage root lesion nematodes.
Root rot in irrigated chickpeas
A number of irrigated chickpea crops in the south east of SA have been severely infected with a root rot, resulting in significant yield loss. These crops were sown in late winter or early spring and grown under center pivots. Samples submitted to SARDI Crop Pathology are currently being investigated for the causal pathogen, and preliminary results suggest a Phytophthora species, Pythium species or possibly a combination of these two fungal pathogens.
Phytophthora root rot is a common problem in chickpea crops in northern New South Wales (NSW) and southern Queensland (QLD), especially where soils are waterlogged. Management strategies include using a metalaxyl seed dressing, such as ridomilɸ, at sowing but the effect of this fungicide wears off after six to eight weeks and infection can still occur. There is no resistance to phytophthora root rot in southern chickpea varieties. Growers and agronomists are asked to monitor chickpea crops for development of root rot and submit samples to Jenny Davidson or Tara Garrard at SARDI (Locked Bag 100, Glen Osmond, Urrbrae 5064) to assist with identification of this problem.
ɸ Ridomil is not registered for use in chickpeas. Rampart or Mantle (containing metalaxyl) are registered for Phytophthora in chickpeas. Commercial users must adhere to label requirements.
Acknowledgments
This research is a collaborative project between the GRDC, DEDJTR and SARDI. The research undertaken as part of this project is made possible by the significant contributions of growers through both trial cooperation and the support of the GRDC, the author would like to thank them for their continued support. Thanks to the technical staff for maintaining trials and collecting and entering data.
Contact details
Jason Brand
Agriculture Victoria
DEDJTR Victoria PB Bag 260 Horsham, Vic, 3401
0409 357 076
jason.brand@ecodev.vic.gov.au
@JasonBrand
GRDC Project Code: DAV1706-003RMX, DJP1607-007RMX, DPI1607-001RTX, UOA1606-009RTX, DAS1306-003RTX, DAS1306-008BLX, CUR1403-002BLX, DAV1306-005BLX, DAV1703-012RMX, DAV1507-002RTX,