The analysts at 20/20 Seed Labs Inc. are well aware of pathogens and diseases that affect certain crop types, and yet, as seed analysts, we are not expected to know or report the pathogens that may be hindering the growth of your sample.
While our primary obligation is to report on germination, we know the seed profile isn’t complete without the opinion of an expert disease diagnostician as well and, luckily, we have one on staff.
This season has been especially challenging because many of the germination samples are infected with pathogens that are hindering seedling growth in germination tests.
Wheat is especially affected. There are a number of mycelium and molds that grow rapidly on the germination test. They are present because of the wet fall and have become an issue during storage. The good news is that if we find an infection on your germination test, it doesn’t necessarily mean the seed is not fit for use. It often means simply that we should re-test the seed in soil, or we should hand treat with a recommended seed treatment before running the test again. We also recommend doing a Fungal Screen™ to accurately identify and quantify the pathogens that can impact seed use.
Some of the most common disease pathogens that affect your samples, especially wheat, are the various Fusarium spp. – and not just Fusarium graminearum. But, because Fusarium graminearum can exhibit the same rose coloured mycelium as all other Fusarium spp., we recommend the DNA-based Fusarium graminearum test to make a positive identification. (See attached images)
Barley and wheat both are affected by a number of other pathogens, Cochliobolus sativus (common root rot) being the most prevalent. Also significant are foot and root rot on barley, and Septoria spp. on wheat seedlings – a leaf blight that causes shriveled seed.
Alternaria spp., Cladosporium spp. and Epicoccum spp. are all saprophytes, meaning they grow on dead tissue, like crop residue. Infections from these pathogens occur frequently and are also randomly observed on the germination blotter. Aspergillus spp. and Penicillium spp. surface infections can also become problematic during storage.
This season, most samples have some level of infection, particularly in seed that was subjected to a delayed harvest or was left to dry in the swath for extended periods of time. Our analyst’s comments on the Report of Analysis will notify you if we have found enough infection for you to consider doing a Fungal screen™, or retest with a seed treatment, and we are happy to assist you with that decision.
Most infected seed can be corrected, if the seed has good germination potential, by using a recommended seed treatment. Knowing what lurks on your seed is very beneficial, and making the right seed treatment choice is even more beneficial.
Please call the laboratory at 1 877 420 2099 for more information.
