TriCal Australia knew it could help solve yield problems on an onion farm in Myalup, WA. Soil health was deteriorating, with higher rates of Pink Root, Rhizoctonia, Fusarium, Verticillium wilts, Sclerotinia, Pythium, and parasitic nematodes all being detected in soil DNA tests.

Not surprisingly, this was having a profound impact on the produce harvested on the farm. In a short amount of time, a unique trial was designed with two aims:

• Explore the extent to which soil fumigation and soil biological products complement each other.
• Assess the economic benefits of a two-crop cycle, specifically onions followed by potatoes.

The farm manager’s attention to detail throughout the trial made the crop an outstanding success. Soil tests were done before and after fumigation by TriCal’s Agronomist.

The results helped to prescribe the necessary products and fumigation rates and demonstrate to the grower the reduction of pathogen levels.

The results were that soil fungal diseases, specifically, Pink Root, were very well suppressed, allowing for a great improvement in yields.

TriCal Australia fumigated a 20ha trial in the Murray Bridge area where a grower’s yield was suffering due to Pink Root in older cropped onion soils. The soil was fumigated and two weeks later the variety Redwing was planted on half of a centre pivot. The other half was not fumigated and sown to Redwing.

Pink Root was suppressed by the fumigation treatment and tracked using SARDI’s DNA diagnostic soil tests. The unfumigated crop was severely infected with Pink Root and yields suffered with a 20mt/ha reduction to record 70mt/ha. The fumigated crop yielded 90mt/ha.

The quality of the fumigated onions was higher and kept their quality after storage.

The grower maximised the benefits of the onion fumigation by following up planting a seed potato crop.

To learn more about what soil fumigation can do in your fields contact us at 08 8347 3838 or info@trical.com.au