Green pea project targets increased yields for growers

INCREASED YIELDS: TIA and Simplot collaborate on vegetable project. Picture: Supplied
INCREASED YIELDS: TIA and Simplot collaborate on vegetable project. Picture: Supplied

Each year Tasmanian vegetable growers produce approximately 24,000 tonnes of green peas.

Tasmanian Institute of Agriculture has partnered Simplot Australia in a three-year Horticulture Innovation Australia funded project to work with pea growers in achieving an average yield target of eight tonnes per hectare by the year 2020.

The pea grower representatives, Pea and Bean Productivity Group, identified plant establishment as a focus area, as this is the foundation for achieving maximum yield.

Pea plants compete for light, water and nutrients.

Tim Smallbon

Pea plants compete for light, water and nutrients; essentially for growing space. An even distance between and within rows spreads resources evenly between plants, evening out this competition.

Institute research confirmed that modern pea cultivars still produce a maximum processing yield at approximately 100 plants per metre squared across both eight- and five-inch row spacing.

At this density, when the spacing between plants is closer to even between and within rows (five inch rows), yield was increased further.

We compared drill performance and found a high level of variability both across the paddock and with individual drill units. Improving ground preparation and drill performance can increase margins by up to $750 per hectare.

Even emergence and establishment is the key to a high yielding pea crop. To germinate and emerge evenly seed needs good soil contact, a constant planting depth and uniform moisture.

Rough finish and clods in paddocks compromise depth and seed soil contact. Late emerging seedlings are easily damaged by herbicide, out-competed and won’t mature by harvest.

Earlier research by the institute and Simplot has also shown that flowers and pods readily abort in response to competition, and irrigating during the flowering and pod fill phases plays a significant role in their retention to maximise yield.

Also, applying preventative fungicides under high disease pressure can further increase returns by up to $350 per hectare.

For the forthcoming pea season, the project team will continue researching optimal crop performance by manipulating the plant density in commercial pea production across a representative section of farms.

A key focus will be optimising drill set up and bed preparation, and the collection of data on grower inputs and practices to provide further insight into best management practice.

To gain a greater understanding of how plant architecture contributes to yield, in conjunction with Simplot, the institute will select crops to represent a range of establishment and yields and map plant architecture against the crop outcome.

Recording data on plant size, branching, pod development, strategic irrigation management and yield outcome will inform the productivity group and growers on the best practice management strategies to achieve the long-term goal.