THREE YEARS of trial field pea research on the Eyre Peninsula have yielded a recipe for higher-yielding crops in low-rainfall areas on sandy and loam soils.
Brendan Frischke and Larn McMurray o f the SA Research and Development Institute said soil types varied from a red-brown sandy clay loam at Minnipa to sandy loams at two other sites, and the average growing season rainfall was 205 mm in 1999, 292 mm in 2000, and 250 mm in 2001. All locations had similar rainfall in the three years. The trials were conducted, with support from growers and the Federal Government through the GRDC, at Minnipa Agricultural Centre and on farmers' properties at Wudinna and Rudall from 1999 to 2001.
Field pea best bets
- Sowing soon after the seasonal break (0-2 weeks) is a key to higher yields. At Wudinna for example, the Parafield variety averaged 1.9 t/ha over three years when sown soon after the break, but suffered an average yield loss of 0.2 t/ha for each week of delayed sowing. The researchers say the yield penalty for later sowing out weighed any loss caused by higher disease levels on the plants linked to early sowing.
- However, they also say, disease management practices are still vital. To maximise yields from peas and to reduce the risk o f black spot disease losses, there should be an interval of four to five years between pea crops in the same paddock. Buffer zones between previous years'pea crops should be adhered to. In paddocks with a history of peas, especially if downy mildew has previously been detected, use the appropriate fungicidal seed dressing.
- Growers need to achieve a plant density of 40-45 plants/m2 for tall varieties such as Parafield and 60- 70 plants/m2 for shorter varieties such as Santih in the trials, there was a yield penalty of up to 15 per cent when plant densities were below 30 plants/m2 for tall conventions types like Parafield . The researchers say good establishment is not only vital to maximise yields but also to increase water-use efficiency and provide competition with weeds.
- Paralield was the highest-yielding variety in the trials, and also in other research on Eyre Peninsula, and is considered by the researchers to be the best current varietal option for EP low-rainfall areas.
The researchers say that in some years Parafield , like the older varieties Alma and Dundale, can produce short vines and reduced vegetative growth , so increasing the erosion risk on light soils. "These limitations need to be solved with farm management practices such as retaining as much of the previous year's cereal stubble as possible and leaving pea stubbles ungrazed," they say.
Program 2 Contact: Mr Brendan Frischke 08 8680 6206 Mr Lorn McMurray 08 8303 9661