Ontario’s growers cope with frost damage

by SUSAN MANN

Last weekend’s widespread frost across Ontario caused variable damage in crops but it’s too soon to say how severe the injury was as many crops may recover, say industry spokespeople.

It’s also still too early to estimate growers’ economic losses, says Pam Fisher, berry crop specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.

Agricorp spokesperson Stephanie Charest says by email of the five million acres insured under Ontario’s production insurance program, about three per cent have been reported damaged. The damage reports are up to the end of Tuesday. It’s too soon to know how many of the damaged acres will need to be reseeded.

Frost damage is an insured item under the crop insurance program and the program provides a reseeding benefit to cover the costs of replanting a crop.

The cold weather was widespread across Ontario Friday night into Saturday morning and the damage reported was also spread across the province. “It’s too soon to know the extent of damage, if any, and there doesn’t seem to be any one area or specific crop impacted more than others,” Charest says.

Horst Bohner, agriculture ministry soybean specialist, says the frost damage to field crops was spotty across southwestern Ontario and growers, especially those using no-till, should check their soybean fields to see if any plants have been killed. “I have seen a few soybean fields that need to be replanted.”

Dry conditions exacerbated the problem caused by freezing temperatures in no-till soybeans. “When it’s very dry the soil does not radiate much heat,” Bohner says.

There’s lots of visual damage on corn, mainly on crops grown on lighter or muck soils or ones located in dips in a field. “Most of that corn will recover even if it has been hit by frost,” he notes.

Bohner says the soybeans that were damaged are in fields with a lot of corn residue on the surface and planted during the first week of May or earlier. “A lot of the fields actually only have maybe 50 per cent plant mortality. So you go down a row and about half the plants are dead and the other half have survived.”

In those cases, growers are advised to keep the existing stand, drive in with a planter and over seed with the same variety to thicken up the stand.

In soybeans, it got so cold in some areas that entire fields had to be written off. Some growers have had to replant 300 acres, while others just had to replant one field here or there, he says.

Similar to disease or insect damage, it’s hard to generalize how severe the frost damage was across Ontario, Bohner notes. “If you have the problem, you need to address it and it’s serious for you.” But the good news is that it’s early enough in the season and if growers reseed immediately the yield impact won’t be that dramatic.

For tender fruit, grape and horticulture crops, growers launched mitigation measures when they heard below zero temperatures being forecast for last Friday night into Saturday morning. But cash crop crop growers can’t do any mitigation because the acres are so vast.

The Friday night/Saturday morning bout of freezing temperatures was considered to be severe for strawberry growers. The dryness of the air and the low dew point (the temperature at which dew forms) meant temperatures dropped quickly. In addition, there wasn’t much soil moisture in the ground to give off heat.

Because the freezing temperatures hit so late in May many crops are “at the susceptible stage,” Fisher says.

Temperatures at ground level where strawberries are growing were much colder than the forecasted -1 C to -2 C. Fisher says one Delhi-area strawberry grower reported a temperature of -6 C at ground level.

Strawberry growers are used to frost and many use irrigation for protection, she says, noting blooms and buds can be injured when temperatures reach -1 C or -2 C. Constant water poured on the blossoms generates enough heat to protect the blossom from frost damage.

But there was still lots of damage from frost to strawberries as not all growers have irrigation and some growers used floating row covers, which helped in some areas but the covers didn’t offer enough protection in the colder areas. Where growers “used irrigation it was successful and where they used row covers, it was somewhat successful,” she says.

There are about 4,000 acres of strawberries grown in Ontario.

Similar to strawberry growers, some blueberry growers used irrigation for protection. Blueberries are at the bloom and green fruit stage and can be damaged when temperatures hit 0 C or lower, Fisher says, noting about 400 acres of the berries are grown in Ontario.  It’s too soon to evaluate the damage from frost on blueberries and growers also have to contend with winter damage.

Niagara tender fruit growers escaped the frost relatively unscathed, notes Phil Tregunno, chairman of the Ontario Tender Fruit Producers’ Marketing Board. “But there were some sour cherry growers up in Simcoe who definitely received some damage to their crops.” The extent of that damage is still being assessed.

Tregunno says there was some ground frost in portions of Niagara “but it doesn’t really affect trees.” Areas close to Lake Ontario were above freezing “while other areas dipped down to -1 C or -2 C or in that area.”

To mitigate the frost, fruit growers had wind machines going to mix the air in their orchards.

Tregunno says what struck him about the frost is its lateness in the season. “In the Niagara area, this is really late to have a frost event.”

The tender fruit crop this year should still be a decent size despite some reports of winter damage to trees. Tregunno says the extreme cold winter temperatures, from -22 C to colder, killed buds even though they were dormant.

For the grape crop, frost damage, if any, won’t be known until July or so when the crop size is determined, says Debbie Zimmerman, CEO of Grape Growers of Ontario. “Frost is much more damaging to annuals, like tomatoes or market garden crops, than it is to grapes, which are pretty hardy.”

“People are tending to see this frost as something worse than what happened during the winter,” she says, adding some varieties, such as merlot, were damaged by very cold winter temperatures.

Similar to tender fruit growers, grape growers had wind machines whirling, while some used helicopters to mitigate damage.

For processing vegetables, about 230 acres of tomatoes were reported to Agricorp with frost damage, says John Mumford, general manager of the Ontario Processing Vegetable Growers. That’s about two per cent of the entire 10,000-acre tomato crop that’s grown in southwestern Ontario, mainly in Essex, Kent and Lambton counties.

The processing vegetable board hasn’t heard of any damage to other crops, such as peas, squash, cucumbers or lima, green or yellow wax beans.

Mumford says some growers held off planting when they heard frost was imminent last weekend, while other growers sprayed water on crops early Saturday morning to head off damage. BF

Update Saturday May 30, 2015

by SUSAN MANN

Frost damage in the Temiskaming, Earlton and New Liskeard parts of Northern Ontario was minimal to field crops, says Daniel Tassé, agriculture development adviser with the Ontario Ministry of Agriculture, Food and Rural Affairs.

Earlton registered -3 C, -4 C overnight last weekend while other areas dipped down to -5 C and -6 C. Those temperatures are considered to lead to a killing frost, something fairly usual for the north at this time of year, he explains. But the plants were just emerging and that helped to contain damage.

“Canola got nipped a little bit on some of the lower land but no one had to reseed canola,” he explains, noting some plants like canola become hardier after being hit with a few days of colder weather and can withstand some lower temperatures.

“I think overall, we didn’t get affected too badly,” he says.

Meanwhile in Eastern Ontario, grape crops in Prince Edward County were damaged but “we won’t know the extent of it for a few weeks,” says Kathleen Greenaway, chair of the Prince Edward County Wine Growers Association. “We’re already starting to see some recovery.”

Greenaway says “things aren’t great but we will have a crop and we will be making wine. It’s just probably going to be a reduced crop.” BF