I told Simon I’d need to come out to his farm first before offering an opinion. When I arrived and had a look at the canola field, I could see there were fewer plants in the rows than there should have been. Simon also informed me it was taking a lot longer than normal for the canola seedlings to emerge from the soil.

I began mulling over possibilities that might have led to the slow and irregular crop emergence in Simon’s canola field.

I knew early-season stressors such as drought, a late frost, high winds, heavy rain or hail can cause seed damage that affects germination and emergence. Soil moisture in the field appeared to be adequate, however, as Simon explained, there was no harsh weather and environmental conditions had been almost ideal for germination and growth after seeding.

I asked Simon about the field’s herbicide history to see if there was anything there that might be affecting the canola. I didn’t see any issues here either — the herbicide he’d applied prior to seeding had been timed correctly to kill early-season and overwintering weeds in the field, and herbicide carryover was ruled out since none of the applications from previous years had restrictions or anything to watch out for in canola.

A review of Simon’s fertility program didn’t reveal any red flags with respect to seedling toxicity, as it was clear from our discussion that 4R-consistent management practices were followed.

When I knelt down to dig around in the soil, I found some germinated canola close to the surface that hadn’t emerged yet. I couldn’t find any insect pests such as cutworms or flea beetles that might have been feeding on the seed, or any sign of damage to the germinated canola either.

The most likely explanation for what was happening lay with seeding operations. However, I didn’t see anything wrong with the seeding rate Simon used during planting. Simon also informed me he used the same seeding rate and seeding depth settings on his air seeder when he planted all of his canola fields, but this was the only one with an emergence problem.

Crop Advisor’s Solution: Check seeding depths throughout planting

While digging around in the field, I found the most likely explanation for the reduced plant stand. Germinated canola sitting just beneath the surface was the clue that revealed what had happened. This led me to dig a little deeper to check the placement of the seeds. What I found was seed that had been planted more than an inch deep in the soil, or more than double the recommended depth for canola.

The seeding depth explained why so few germinated canola plants had made it out of the ground. When I talked to Simon about it, I learned he hadn’t taken into account how the soil characteristics and conditions differed from his other canola fields he had seeded earlier.

The other fields hadn’t been worked and had hard-packed soil, so Simon had increased the pressure on his air seeder in order to place the seed at the required half-inch depth. In this field, where the soil had been worked the previous fall, the increased pressure on the air seeder resulted in the seed being placed too deep in the soil.

There wasn’t anything that could be done to rectify the problem at this stage, but fortunately for Simon, his average plant stand was still greater than two plants per square foot and good growing conditions throughout most of the summer meant he ended up with a viable canola crop.

Simon also learned an important lesson about checking seeding depths throughout the planting process and to make the necessary adjustments to seeding equipment when field conditions change or when moving between fields.

The post Crop advisor casebook: What’s causing this slow and irregular canola emergence? appeared first on Grainews.

“I’ve got plants turning brown and dying off in my soybean field,” he said. That afternoon I set off for Adrian’s 3,500-acre grain farm located just outside of Dauphin, Man.

Adrian is an experienced soybean grower and has been implementing a good rotation of canola, soybeans and wheat. He found a soybean variety he really likes to grow, and he has grown lots of it. Adrian also uses a seed treatment to control soil-borne disease and insects.

In the field, soybean growth and development had stopped. The injured plants had a collapsed and wilted appearance; the leaves were brown, drooping and still attached to the dead plants.

Additionally, the plants had brown lesions on the stems above the soil surface. They also exhibited very poor root growth with no lateral root development. I could easily pull the plants out of the ground because of the small taproots and the absence of lateral roots.

I looked for indications of moisture stress, fertility or seeding issues.

It had been drier than normal that season; however, this particular area had received more precipitation than others in the region and had sufficient moisture. In addition to weather events, some of the injured plants were located in the low-lying areas where there would have been more than adequate moisture. This evidence helped rule out moisture stress.

A nutrient deficiency was also unlikely as the plant symptoms did not support this theory. Additionally, Adrian had a healthy fertility program and his fertilizer rates and placement followed best practices for the soil and crop type.

Seeding issues were also ruled out because seed depth and seeding rates were correct and the seeding equipment was working properly.

The injured plants were more prevalent on the headlands, low-lying areas and in the sprayer tracks.

Crop Advisor’s Solution: Rotate phytophthora-resistant soybean varieties to keep ahead of this fungus

Adrian is an experienced soybean grower. He found a soybean variety he really likes to grow, and he has grown lots of it. This was one clue to solving the mystery.

The other was the location of the injured plants on the headlands, low-lying areas and in the sprayer tracks. The injured plants were more prevalent in compacted, high-moisture areas of the field.

The plant symptoms were caused by an infection of the phytophthora fungus. Although Adrian used a soybean variety that was resistant to phytophthora, because he grew the same variety each time the infection levels built up in the soil, and the variety’s resistance to the fungus was eventually overcome.

The soil compaction and moisture increased the occurrence of phytophthora in those areas. Although Adrian used a seed treatment to protect the seedlings against this fungus, the active ingredient used to control phytophthora, metalaxyl, must be applied at a higher rate in order to control the disease in high-risk scenarios.

It is important to rotate varieties with different race-resistant genes. Field drainage and avoiding unnecessary soil compaction will further improve phytophthora management.

At harvest, only a slight yield loss occurred. In 2018, because of the changes Adrian made with respect to soybean variety, soil compaction and field drainage, very little phytophthora infection was observed in his soybean fields. That year, Adrian’s yields improved.

Crop rotation in conjunction with changing up disease-resistant varieties is an effective strategy to prevent disease build-up and variety resistance.

The post Crop advisor casebook: Soybeans wilt and die off after emergence appeared first on Grainews.