June Guelph Bulletin
DNA LONG SCAN (FUNGAL PATHOGEN DETECTION)
The Long Scan DNA test has been recently upgraded to include two new microorganisms: Aphanomyces euteiches and Macrophormina phaseolina. The Long Scan is most commonly used as a diagnostic tool for greenhouse and specialty crops, and can test plant tissue (leaves, stems, or roots), soil and growing media. Click here to see our full list of 70 microorganisms detected.
With the known reductions in atmospheric deposition of sulphur, and the widespread occurrences of sulphur deficiencies, analysis of soil sulphate-sulphur has been a growing concern. Sulphate-S, which is the plant-available form, is much like nitrate-nitrogen in that it is mineralized and leachable, however it does not experience losses to the atmosphere like nitrogen. The typical range for soil sulphate-sulphur is 3 to 15 ppm, which is equivalent to 6 to 30 pounds per acre of S04. Sulphur uptake for most rotational crops is near 20 lbs/ac, with canola and haylages requiring upwards of 30 lbs/ac.
Sulphur tests on soil can be used to show current levels, as well as a comparison of relative differences across a field’s soil types or from farm to farm. Coarse soils with low organic matter tend to be the most in need of additional sulphur. Fields receiving manure applications have long been considered to not be deficient, however response to sulphur application has been observed in many cases. Adding sulphate-S to a 12” PSNT test proved to be valuable last year, as areas low in N also tend to be low in S.
Early season tissue analysis is also a useful diagnostic tool to identify if crops require additional sulphur. Crops testing below the critical level frequently show a response to sulphur treatment. Our Tissue Complete package includes sulphur analysis.
Sulphur Requirements in lbs/bu:
- Corn: Uptake = 0.11, Removal = 0.07
- Soybeans: Uptake = 0.34, Removal = 0.10
- Wheat: Uptake = 0.25, Removal = 0.08
- Canola: Uptake = 0.62, Removal 0.33
- Corn Silage lbs per ton DM: Removal = 2.00
- Legume Hay lbs per ton DM: Removal = 6.00
BEST WISHES TO NELMY NARVAEZ
After five years of dedicated service with SGS Guelph, Nelmy has accepted a new position in the field of livestock nutrition. We wish Nelmy well as she takes the next step in her career.
More more information, please contact:
Jack Legg, CCA-ON
Branch Manager, Agronomist
Guelph, Ontario N1H 6T9
503 Imperial Rd. N., Unit 1
t: +1 519 837 1600