Heat dome sees crop conditions deteriorate, moisture reserves to plummet

Manitoba Crop Report and Crop Weather report for July 6

Southwest Region

The heat dome reached southwestern Manitoba this week with highs from 31 to 35 C. Minimum overnight temperatures ranged from 9 to 12 C. Trace rainfall only for most of the region. A narrow band of rain north of Neepawa, including Eden, received as much as 10 to 12 mm. Deloraine and area also got same amount 12 mm in the south. All other areas of the region are still very dry and are in need of substantial precipitation soon. Growing degree-days and corn heat units are 95 to 110% of normal; precipitation continues to be below normal in some areas. 

Fall rye and winter wheat are maturing fast and look to be average to below average mostly due to winter kill and cool conditions this spring and now lack of moisture and heat. 

Most spring cereals are heading out. Hot and dry conditions have affected the crop and rainfall is needed within the next week as tillers are starting to show stress. Some fungicide being applied but as conditions remain dry, producers are starting to reduce applications. There could be some issues with barley test weight if heat continues. Fungicide applications will not be made in the driest areas, where crop potential does not warrant treatment. Premature heading due to dry conditions are visible in some areas as height of the plants is shorter than normal. 

Peas are flowering and early seeded peas are in pod fill stage. Crop looks to be average to above average. Very little disease showing up so far. Early seeded canola is flowering and later seeded canola is cabbaging and starting to bolt. Most fields are uneven and mostly due to early growing conditions. Cold weather, flea beetles and drought and extreme heat later on. Corn is doing okay and has handled the heat reasonably well. However, rain is required in all areas, since corn is starting to show moisture stress.

Soybeans are at V3 to R1. The majority of fields are shorter than normal. They have handled dry weather good so far but are starting to show stress with heat and lack of moisture especially on lighter- textured soils. 

Diamondback moth and bertha armyworm counts are low in the Southwest region. 

Most producers have started haying and first cut is underway. Yields look to be average, and rain is needed to spur regrowth to allow for a second cut. Some producers are waiting on first cut to reach maximum dry matter accumulation due to fears that a second cut may not happen. Pastures that were grazed early are in poor condition but recent rain has helped some of the better-managed pastures. 

Dugout levels are quite variable; all are declining, some are dry. Water quality is a concern in low dugouts. Water supply is rated as 60% adequate, but significant rain is needed for replenishment. Water hauling to pasture troughs is occurring in some areas. Concern over adequate supply is increasing with continued dry conditions. 

Northwest Region

Intense heat for a number of days stressed crops throughout the Northwest region. Temperatures reached highs of 36 C with overnight temperatures remaining high as well. Areas that were lacking moisture before the intense heat became more apparent as stresses started to show. A severe thunderstorm through the Swan River and Ethelbert areas Saturday night brought various rainfall amounts from 3 mm up to 50 mm in localized spots. Some hail was reported however, damage is not yet known. Other areas of the region did not receive significant rainfall through last week. Soil moisture conditions have deteriorated further this week and are a continued concern. The accumulated rainfall as a percent of long-term normal is lowest in areas around Dauphin/Ste. Rose in the southeastern parts of the region. Northern parts of the region near Swan River and The Pas, while dry, are faring somewhat better in terms of rainfall amounts and resulting soil moisture conditions. 

Spring cereals across the region are 75% heading out with the remainder following behind in the stem elongation growth stage. Cereals are still rated at 70% in good condition, as they have been better able to withstand the challenging spring conditions. Yield potential of the cereal crop is still positive. Winter wheat and fall rye are heading out and just starting to turn colour in the Roblin and Dauphin areas. 

Canola across the region is highly variable with about 50% of the canola crop in the region rated as good with the remainder in fair to poor condition. The canola is patchy, shorter than normal, stagey and many fields still have bare spots. These effects are the result of dry conditions, insect feeding, spring frost and wind. Most of the canola is bolting and flowering. The exception are those fields that were reseeded or seeded late and these fields are in the rosette/bolting stage. 

Peas are starting to pod. The effects of the ongoing heat stress has caused flower abortion in canola and peas. 

Herbicide and fungicide applications continue as the correct crop stage is reached and conditions allow. The continuous strong winds, heat and intermittent showers across the region have made spraying a challenge. 

Bertha armyworm monitoring continues across the region. The moths are starting show up in some traps however; cumulative trap count numbers remain low. Grasshopper feeding is a continued concern on pastures and cereals. 

First cut hay harvest is underway with more progress made on the eastern side of the region with the hot and dry conditions. More moisture will be necessary for any second cut hay re-growth and to sustain pasture production. Water supplies on pastures are very limited and many producers are moving cattle off pastures due to water shortages or having to haul water to pastures. Corn for silage is growing well with the heat. Grasshoppers continue to be a problem. Much of the eastern part of the area has had very limited moisture including Ste. Rose and Rorketon through to Alonsa with less than 60% of normal precipitation. 

Central Region

Sunny, hot conditions prevailed last week with moderate wind speeds and variable directions throughout. A thundershower system in the southern part of the region on the weekend brought precipitation to isolated areas along the international border, with a maximum rain of 22 mm in the Altona and Gretna areas. Much of the rest of the region received little to no rain. Topsoil moisture is very poor to fair with more rain needed to replenish soil moisture in all areas of the region as crops are growing and evapotranspiration is high. Sunny and cool to warm temperatures are in the forecast this week, with only a chance of showers which should continue to stress crops and forage stands. 

Winter cereals and perennial ryegrass fields are turning colour. Fall rye and winter wheat fields are grain filling with more advanced rye fields in the soft dough stage and visibly turning. 

Wheat, oats and barley are holding west of the escarpment where cooler temperatures and moisture conditions have been more favourable than in the Red River Valley and northern parts of the region. Many cereal fields are extremely short this year, being stressed from moisture deficit and higher temperatures. Development varies from the early head emergence to finished flowering in earliest wheat fields. Some fungicide applications by ground and by air are going on in some fields with higher yield potential to protect against fusarium head blight. Growers in dryer areas are hesitant to apply fungicide protectant. Aphid activity reported on wheat along with some of their natural predators. 

Corn growth varies with moisture conditions and stage ranging from V5 to V8. Leaf rolling noticed on fields suffering from moisture deficit stress as plants attempt to preserve moisture. Second pass herbicide is wrapping up as canopy closes. Field peas are looking fair with most fields flowering to early pod development. Some fungicide has been applied to fields with good yield potential. European corn borer pheromone traps have been set up in 11 field locations where infestations may get high. 

Canola staging varies greatly, from rosette to almost done flowering in the more advanced fields. Some fields are very stagey with plants from seedling alongside other plants flowering. Fungicide application is going on uniform fields with good yield potential and favourable moisture conditions to protect from sclerotinia while many fields are struggling with soil moisture deficit. 

Flax is flowering but short in stature, with some preventative fungicide application on better fields. Sunflowers are tolerating the warmer and dryer conditions prevailing now up to about V6 to V10 stage, some reaching R1. 

Soybean fields are into the 5 trifoliate to early flowers (R1) in many fields. Herbicide applications are mostly done in soybeans. Moderate temperatures and sunny conditions are forecasted this week allowing for spraying operations to continue where needed. 

Potato crops are at different stages of tuber formation and need supplemental irrigation given the lack of rainfall. Minor reports of blackleg and early blight symptoms have been seen. Colorado potato beetles are now active in some more fields. 

Cereal armyworm pheromone baited traps remain in place with low cumulated counts in the region so far. Bertha armyworm traps are in place to monitor the emergence of this potential canola pest over the next few weeks. Trap counts are generally low in the region but a few more weeks of trapping remains. Grasshoppers are a concern to crops in some areas and the crops are under stress. Control measures are being applied to field headlands in the southeastern part of the region. 

Haying is progressing well with the dry conditions, quality is good but yields are below normal with older hay fields well below normal. Hay fields and pastures are browning off and there will be no second cut in the drier areas. Crops, hay and pasture need rain or yields and growth will deteriorate further. Pastures are in better condition where there has been more rain. Overall growth is sufficient for the grazing livestock so far. Grasshoppers and alfalfa weevil are still a concern. 

Eastern Region

Rainfall recorded at the Eastern weather stations ranged from zero to 37 mm across the region. Areas in the southeast parts of the region received rain while northern areas did not. Crops in southern areas that did get some rain are doing better. Both day and nighttime temperatures were well above normal during the reporting period. Stress from lack of moisture became very evident on crops during the reporting period. Sandy and gravel ridges in fields became very evident as they demonstrated the most evident moisture stress symptoms. Areas with poorer water holding capacity in their subsoils demonstrated the most severe symptoms and the greatest loss in yield potential but yield potential has been negatively affected to some degree in all annual crop fields. Crop development is being pushed on at a rapid pace with the high temperatures. 

Winter wheat and fall rye heads are filling. Some cereals are prematurely firing the lower leaves. The crop is now at maximum moisture demand with filling going on. 

Spring cereals are at flowering to early seed fill. Corn is at the V6 to V9. Leaf curling due to lack of moisture very evident, especially in the hot afternoons. Some lower leaves firing in some fields. Pea crops are at flat pod or R3 growth stage with very low disease levels in upper and lower canopy. Some fields looking flaccid in the heat with lower leaves drying up. Flower blast was observed as well. Sunflowers are at bud or R1 stage. Crop showing no signs of lack of moisture stress, with deep tap root reaching down into subsoil moisture. 

Canola is at rosette to bolt and a few flowers on reseeded acres. Bloom stage ranges from 10% to 50% flower on original crop. Heat has caused lots of flower drop (heat blast) and some fields moved from 20 to 50% flower in a few days. Many canola crops looked good until the heatwave; the biggest concern at the moment is the amount of heat blast on flowers. All flax is flowering. Excessive flower drop evident and drying up of lower leaves was observed. Soybeans are at R1 (at least one flower at any node) to R2 (at least one open flower on top two nodes on main stem) on original and reseeded crop. Symptoms of N ‘flash’ as nodules started and IDC have receded. Some water stress leaf- flipping going on in heat but crops are handling heat better than cereals and canola. 

Concerns regarding aphids in cereals are starting to subside as the crop advances. In some fields, natural predators did a good job on controlling aphids. Grasshoppers became the primary insect concern, but there has been only limited spraying in a few hotspots. Overall lots of scouting going on but grasshopper numbers and damage levels have not been as high as was expected. Scouting continues and farmers expect grasshopper feeding to worsen if the dry conditions continue. 

Some producers are reporting 90% of normal first-cut alfalfa yields down to 40% in areas that had a significant moisture deficit. Beef producers are also well into first cut and some are reporting very poor yields (40 to 70% of normal) due to lack of moisture. Native and tame grass stands have been cut however they seem to be fairing the worst at this point with yields as low as 30% of normal in the driest areas. Pastures are struggling and showing the greatest amount of stress in continuous grazing pastures or previously overgrazed pastures. Some reports of dugouts drying up. 

Further north, dairy hay second cut has not yet started. Lack of rainfall is not promoting very good regrowth. For both dairy and beef hay, level of stand management and luck in getting timely rain from a few weeks ago remain the two most important factors determining hay yields. Tame Beef hay is about 95% cut and 90% baled but with rapid progress last week. Hay was drying very fast in all cases with some producers baling less than 24 hours after cutting because the hay was basically dry when cut (particularly true with wild hay), an indicator how dry and hot the reporting period was. Wild hay about 30% cut and baled with yields less than 50% of normal. Quality seen as fair to average. Pastures condition deteriorated rapidly last week with feeding on pasture continuing. Again, past management was having an effect on current productivity. 

Producers became more concerned about feed supplies going forward. Increased rainfall over the coming weeks will be critical if improvements in the situation are to occur. Livestock water availability is rated as adequate. 

Interlake Region

All crops in the region experienced the brunt of the heat dome this week, coupled with very dry soils and previously drought- and insect- stressed crops, growth has stalled in many fields. 

Crop conditions have deteriorated noticeably, and minimal fungicide application has been made to any crop due to dry conditions and limited yield potential. 

Winter cereals are starting to turn colour. Spring wheat and barley are fully headed out, while some later oat crops are still doing so. Some fields appear evenly uniform, while other vary significantly. The impact of spring tillage or moisture conservation practices is obvious. 

Peas are flowering, but heat blast on flower was noted. The earliest fields are at R3, flat pod stage. 

Soybean crop conditions are variable, from very good shape despite the heat wave to poor condition. Soybeans over sandy or shale subsoils are noticeable poorer, as with all crops. Flax crops are in full bloom. 

Sunflowers are shorter than normal, with the earliest fields now at R1 stage. Cornfields look noticeably drought-stressed with spindly, rolled leaves during hot afternoons, with little chance for reprieve overnight. 

Grasshoppers are causing damage in hay, cereals, corn and soybeans. Insecticide spraying is occurring on hay, pasture and cereal fields so far. 

First cut haying is nearly complete; yields are between 25 to 40% of normal. Minimal regrowth has occurred, and many hayfields are brown. Livestock water supplies are short, with hauling to pasture sloughs and tanks ongoing. New wells are being drilled, and existing dugouts deepened to access any available water. 

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