A key challenge in rapeseed cultivation is uneven ripening and yield losses during harvesting—sometimes even before harvesting begins—when the pods start to crack, causing the seeds to spill onto the ground. Many farmers are familiar with the situation where, a week or two before harvesting, the field begins to literally "crackle" as the pods burst open, and potential income is lost to the soil. As a result, besides reduced profits, there is also volunteer rapeseed growth, which will need to be managed in the following season.
One of the main reasons for pod shattering is the daily moisture fluctuation during ripening. During the day, the pods dry out, and at night, they absorb moisture. As they dry, they contract; as they take in moisture, they swell. These repeated "drying-swelling" cycles during ripening cause pod walls to deform and weaken the pectins responsible for their mechanical strength. This further weakens the seams. Under these conditions, the deformed pods become highly susceptible to shattering—even the slightest disturbance from wind or contact with machinery can cause them to burst open.
Even growing varieties with some resistance to premature shattering does not completely solve the problem.
By using agricultural drones during the final stages of rapeseed ripening, it is possible to avoid physical contact with the plants, unlike when using wheeled sprayers. The specialists at "AGRONIX" have been helping farmers apply pesticides with agricultural drones for the fourth season in a row.
HOW TO PREVENT POD SHATTERING AND YIELD LOSS?
1. Use of Special Pod Sealants
When the pods on the lower tier begin to turn brown and can be bent into a "U" shape without splitting along the seam, this is the optimal time to apply a bio-adhesive.
Farmers typically use chemical and biological adhesives, such as:
- Chemical adhesives create a continuous film that seals the pods and dries them out. However, this film restricts respiration and photosynthesis, which can hinder seed maturation and reduce its quality. Therefore, the use of chemical products in this case raises some concerns...
- Biological alternatives do not damage the protective tissues and do not interfere with further vegetation, allowing the pods to mature naturally.
If we take one of the most popular products, "LIPOSAM® adhesive," as an example—where the manufacturer recommends a lower application rate when using agricultural drones—then the saved 1 liter of adhesive per hectare (approximately 240 UAH/L) already offsets the cost of using a drone instead of a wheeled sprayer.
As for potential yield losses due to pod shattering, let's take the minimum values: yield – 2.5 t/ha, losses – 10%. If the rapeseed price reaches $450 per ton, this results in a loss of $113 per hectare. If anyone is curious about how much money can be left on the ground with a yield of >3.0 t/ha and losses of >20%—calculate it yourself. Just remember, after doing so, you won’t be able to sleep peacefully at night until you apply adhesive to your rapeseed.
So, if there is even the slightest risk of rapeseed pod shattering, the question of "Should we apply adhesive or not?" is completely irrelevant. Instead, the real question should be: "How should we apply it?" If the rapeseed has grown to a height of 2 meters or more, entering the field with wheeled machinery might not even be possible. In this case, agricultural drones are the optimal solution, which is readily available in the arsenal of AGRONIX.
2. Rapeseed Desiccation
Rapeseed’s Susceptibility to Shattering Isn’t the Only Issue Another major challenge is the biological characteristic of uneven ripening. A couple of weeks before harvesting, it's easy to notice that the upper pods have already turned brown, the seeds are black, and harvesting could begin. However, looking at the lower layers of the plant, the pods are still green, and the seeds are not fully developed. By the time the lower pods ripen, the upper ones will over-ripen and start shattering. As a result, anywhere from 10% to 50% of the potential yield ends up on the ground instead of in the harvester.
To avoid this problem, farmers perform desiccation—pre-harvest drying of plants to accelerate ripening by 5–7 days and facilitate harvesting. Desiccation is particularly effective in weedy fields and under humid weather conditions, making it one of the key measures for preserving crop yields.
Today, plant drying is carried out using desiccants based on diquat, glufosinate-ammonium, and glyphosate. Desiccation is typically performed about 10 days before harvest. Importantly, this process does not damage the seeds or tubers of maturing crops, while simultaneously creating optimal conditions for harvesting machinery. Additionally, desiccation helps suppress perennial weeds, improving field conditions for the next crop in the rotation. This method is particularly effective in fields with moderate to high weed infestation.
Unfortunately, agricultural producers do not always have the opportunity to carry out rapeseed desiccation on time due to difficulties in moving equipment across the field after heavy rains or the insufficient clearance of available wheeled sprayers. In such cases, the company "AGRONIX" promptly meets the needs of farmers by applying desiccants using agro-drones.
For accelerated and uniform ripening, crop desiccation is carried out 7–10 days before harvest using ammonium glufosinate. As a result, treated plants rapidly accumulate free ammonia to toxic levels, giving the product its so-called burning effect—causing a quick browning of green plant tissues. Additionally, the inhibition of glutamine synthesis leads to a slower but more prolonged effect. The toxicity of ammonia, glutamine depletion, and rapid suppression of photosynthesis ensure the fast and highly effective action of ammonium glufosinate as both a desiccant and a broad-spectrum herbicide.
Depending on weather conditions, full desiccation of cultivated plants occurs 10–14 days after the application of the product. Precipitation affects the effectiveness of the product during the first 6 hours after application. The intensity of rainfall has a greater impact than the interval between the application of ammonium glufosinate and the rain. Thus, products based on ammonium glufosinate reduce plant moisture while simultaneously accelerating and evening out the ripening process, improve quality (germination, growth vigor, 1,000-grain weight, and grain nature), increase yield, reduce seed losses, facilitate and lower the cost of harvesting.
To reduce harvesting time, products based on diquat are used. These products not only halt plant development, from the root system to the generative organs, but also extract moisture from the treated plant. It is due to dehydration that the treated plants die off, as the active ingredient's mechanism includes a drying effect. Thus, the use of diquat-based products ensures the primary goal of desiccation – a sharp reduction in seed moisture. If the recommended methods for preventing crop damage by wheel sprayers are followed—high clearance, narrow wheels, covering the front axle and tractor undercarriage with polyethylene film, equipping front wheels with deflectors, positioning the sprayer boom at the optimal height for even application—this will help reduce seed shedding. However, at least 5% of the yield will still be lost due to the existing technological tracks and the physical interaction of certain machine components with the plants.
When applying desiccants and adhesives using AGRONIX agricultural drones, it is possible to avoid even these +/-5% losses.
To understand the economic aspect of this operation, let’s examine the following table.
From this table, it becomes clear that even at the lowest levels—when yield is relatively low and losses are only 3%—there is a deficit of $34 per hectare. As yield increases and losses exceed the 5% mark, the amount of unrealized profit easily reaches $100 or more per hectare.
And finally, even after applying adhesives, conducting desiccation, and harvesting rapeseed on time, losses from technological tracks still remain. In other words, technological tracks themselves cause a portion of the yield to be lost. If we take actual trampling area values of 3%, 5%, and 7% (depending on the sprayer’s working width and wheel size), we can calculate the return on investment in an agrodrone for pesticide application on rapeseed.
It is enough to treat between 400 and 900 hectares of rapeseed with an agrodrone to eliminate losses from the technological tracks of wheeled sprayers. As a result, the investment in an agrodrone and a set of equipment will pay off in just one season.
If you go further and cover even more area "without technological tracks" using an agrodrone in one season, you can also make a solid profit from it.
