The late flowering field pea variety Kaspa was not favoured by the dry spring conditions across SA last year, a result similar to that found in 2006 and 2007.
Generally at low rainfall short growing season National Variety Trial (NVT) and Pulse Breeding Australia (PBA) evaluation sites the earlier flowering white pea varieties Bundi, Sturt and SW Celine were higher yielding.
The powdery mildew resistance dun type pea Yarrum was also higher yielding than Kaspa at many sites last year.
All fifteen NVT and PBA field pea trials in SA in 2008 were successfully harvested. Mean grain yields ranged from 0.4 t/ha at Lameroo through to 2.7 t/ha at Riverton and were generally similar to yields achieved in 2007.
Pea variety performance last year was variable across districts despite most sites being affected by post flowering moisture stress. This was due to variable levels of heat and frost stress during grain filling occurring across the sites.
The presence of powdery mildew and viruses at the South East sites also complicated variety performance.
Yarrum, for the second year in a row, was the highest yielding variety in 2008 averaging 15 percent higher than Kaspa across all sites. Sturt was also high yielding with an 11 percent yield advantage over Kaspa.
Yarrum is a late flowering dun pea released for northern Australia. It has resistance to powdery mildew and improved resistance to virus.
These traits aided its performance at the three South East sites this year where it had its highest relative yields. It also had high yields at the high yielding sites of Riverton and Turretfield.
Yarrum had low yields at highly moisture stressed sites where the season ended abruptly such as Balaklava and Snowtown.
In previous years despite its late flowering characteristic, Yarrum has handled the short and dry flowering and pod fill seasonal conditions better than other varieties.
However in these previous cases, despite the dry finishes, high temperatures events during podfill were less extreme than they were in 2008.
Despite its strong performance over the last two years in SA, Yarrum previously has performed more moderately in this state. It does however provide an alternative to Kaspa in SA where powdery mildew and viruses are regular problems.
The cross-sites grain yield average of Kaspa and Parafield was similar over all trials in 2008 in a repeat performance of 2007.
Kaspa best relative yields were at the sites where finishing conditions were more favourable.
Kaspa’s resistance to downy mildew has now broken down in many regions of SA.
This was observed at Balaklava in 2008 where like Parafield it was rated as susceptible to this disease.
Kaspa will now require an appropriate seed dressing to avoid infection and yield loss to downy mildew in disease prone areas of SA.
Despite Kaspa being lower yielding than a number of varieties in the recent dry seasons it remains a good option for many areas of SA due to its combination of dun seed type, erect plant type, high yields in favourable environments and resistance to shattering.
Early sowing has been practiced in many regions to stabilise Kaspa’s yield in dry finishes.
However considerations for blackspot and frost risks must occur before employing this strategy.
In bacterial blight prone areas Parafield, Yarrum and Sturt will provide a lower disease risk option than Kaspa.
The white pea type Sturt had high relative yields at sites with high levels of post flowering moisture stress and frost.
This is a result consistent with previous findings. Sturt has consistently had higher yields than Kaspa at low rainfall sites and is now higher yielding than this variety long term in these environments.
Sturt had lower yields than Kaspa at sites with more favourable finishes like Riverton and Turretfield.
It also has increased sensitivity to metribuzin which can be a concern.
Sturt like Bundi and SW Celine are white pea types and growers need to secure markets before sowing these varieties as they are segregated and marketed separately to dun types.
OZP0602 and OZP0601 from PBA Field Peas are ‘Kaspa’ types with earlier and longer flowering periods and greater yield in short season environments and seasons than Kaspa.
OZP0602 has been higher yielding than Kaspa at 22 of the 28 NVT and PBA evaluation sites in SA over the last two seasons.
Agronomic trials funded by the SA Grains Industry Trust at Hart and Turretfield in SA in 2008 showed that OZP0602 and Kaspa had similar grain yields when sown on the opening break but OZP0602 was higher yielding when sowing was delayed.
OZP0602 may not need to be sown as early as Kaspa to maximise yields, providing a safer option where sowing needs to be delayed.
OZP0703 is a high yielding early flowering dun variety with greater tolerance to bacterial blight (pv syringae) than current pea varieties.
It was higher yielding than Kaspa at 11 of the 14 evaluation sites in 2008 averaging 17 percent higher.
These three lines are currently under multiplication with AWB Seeds with a view to releasing them in 2011.
