Hey there, time traveller!
This article was published 2/7/2016 (1908 days ago), so information in it may no longer be current.
That old saying among farmers "rain makes grain" has never been truer than this year after timely rains arrived late in May, just in time to get this year’s crop off to a lush start. Some were even calling it the "billion-dollar rains."
But warm, humid weather like we’ve experienced in recent weeks also brings on the weeds and diseases that threaten to cut yields and crop quality.
Like it or not, the majority of farmers rely heavily on crop-production products — herbicides, fungicides and insecticides — and spraying is an important part of their production cycle.
It’s not just the threat to the farmers’ incomes targeted by these operations. Crop diseases such as fusarium head blight leave behind mycotoxins in cereal crops that are a health threat to the humans and livestock that eat them. Keeping infected wheat out of the food and feed chain not only involves farmers at the field level, but grain handlers and federal quality inspectors.
Despite decades of research, breeding genetic resistance into wheat varieties has been difficult to achieve. Farmers have turned to fungicides as their best defence.
When it comes to spraying, it’s exceedingly complicated synchronizing weather with crop staging in order to apply the right products at the right time. Different diseases strike at different times. Leaf spot diseases, which also compromise yield and quality, strike earlier than fusarium, which causes the most damage when the plant is flowering.
A lot of farmers, on the recommendation of manufacturers, have looked upon fungicide applications as good insurance against yield loss due to disease. As solutions go, it’s imperfect at best.
New research released by Agriculture and Agri-Food Canada researchers suggests farmers are being a bit too zealous when it comes to applying fungicides to control fusarium head blight and leaf spot diseases in their cereal crops.
Researchers Myriam Fernandez and Bill May studied the timing and frequency of applications of the commonly used triazole fungicides on durum wheat crops in southeast Saskatchewan between 2001 and 2006. They said their findings would apply to other types of wheat.
They found the so-called insurance applications in the absence of disease pressure offered little protection and were less effective than applying the fungicides when disease was most likely to strike.
It also raised the likelihood of the farmer having to buy two fungicide applications, which not only increases their cost, but raises the potential for quality losses.
Their research showed while early and double fungicide applications resulted in yields ranging from four to 8.5 per cent higher, there was a negative effect on quality. The fungicides suppressed the fusarium and leaf spot, but there was a significant increase in other fungal diseases such as black point and red smudge that cause discoloration and downgrading.
Black point increased by 47 per cent on crops treated with fungicide early and by 76 per cent on double applications compared to no fungicides being applied.
"None of the results support the recommendation that fungicides be applied to durum wheat crops on a ‘preventive’ basis, to increase grain yields," their report says.
Fernandez cautioned overuse of fungicides also hastens development of resistance, just as weeds have developed resistance to commonly used herbicides.
These create a dilemma for farmers.
Intensive cropping has increased disease pressures. If they don’t use fungicides, studies show they could lose between $35 to $87 per acre, largely due to downgrading of their crop. If they do use them, they are spending about $20 an acre for product but risk having their crop downgraded due to other diseases. Dropping a grade reduces the value of wheat by $10 to $12 an acre.
Fernandez and May suggest the industry needs to look beyond fungicides to cultural practices such as crop rotations and plant breeding for genetic resistance.
In the end, there won’t be one solution, but several that provide the best protection.
Laura Rance is editor of the Manitoba Co-operator and editorial director for Farm Business Communications. She can be reached at firstname.lastname@example.org or 204-792-4382.
Laura Rance is editorial director at Farm Business Communications.