IS THE seed you're planting really clean?
Like the majority of Victorian farmers you would probably be inclined to answer in the affirmative, particularly if your seeds has been cleaned.
But you may get the same shock Victorian farmers did from a survey held last year by researchers from the Victorian Institute for Dryland Agriculture.
From seeds ready to be sown last year, 160 cereal and pulse samples were collected and the level and species of weed seed were determined.
A wide-range of weed species was found in farmer-retained seed which contained a higher level than certified seeds.
A total of 72 cereal samples, mainly wheat and barley, revealed the main foreign seeds were annual ryegrass, volunteer canola, volunteer barley, wild oats, silver grass, volunteer wheat, brome grass and volunteer oats.
The percentage of weed-free samples in wheat and barley were 26pc and 21pc respectively.
A total of 88 pulse samples, mainly lentils, beans and peas, revealed the presence of narrowleaf clover, wireweed, annual ryegrass, vetch, medic and volunteer field peas as the main contaminants.
According to Victorian researcher Michael Moekerk, one of the most important and often overlooked factors in crop establishment was the level of foreign seed contamination.
"As well as adding to the weed burden, it also contributes to the introduction of unwanted species to the farm," he said. "We found a number of farmers who were surprised by the level of weed seed found in their professionally cleaned samples."
Farmers ranked wild radish, annual ryegrass, Paterson's curse, brome grass, silver grass, and vetch as the weeds positing the most serious problems to their farms.