5 Best Crop Oil Concentrates For Foliar Feeding Old Farmers Swear By
Explore 5 crop oil concentrates trusted by veteran farmers. These essential adjuvants enhance foliar spray efficacy by improving absorption and coverage.
You’ve spent good money on foliar fertilizer, but after spraying, you watch a light rain wash it right off your waxy cabbage leaves. Or maybe you’ve hit that patch of stubborn thistle with an herbicide for the second time, and it just looks annoyed. The secret isn’t always a stronger chemical; sometimes, it’s just making the one you have work better.
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Why Old-Timers Add Crop Oil to Foliar Sprays
A crop oil concentrate, or COC, is basically a turbocharger for your sprayer. It’s a special type of adjuvant, which is just a fancy word for something you add to a spray tank to improve its performance. Think of it like adding soap to water to wash greasy hands; the oil helps your spray do its job on a plant.
These oils serve three main purposes. First, they act as a surfactant, breaking the surface tension of water droplets so they spread out across a leaf instead of beading up. Second, they work as a "sticker," helping the spray adhere to the leaf surface and resist washing off. Finally, and most importantly, they act as a penetrant, helping to dissolve the waxy outer layer of a leaf so the nutrients or herbicides can actually get inside the plant.
You’ll generally run into two types: standard petroleum-based oils and methylated seed oils (MSOs). Petroleum oils are the reliable standard, while MSOs, derived from vegetable seeds, are often more aggressive and faster-acting. Choosing between them depends entirely on what you’re spraying and what you’re spraying it on.
Drexel Pen-A-Trate II for Tough-to-Wet Weeds
Some weeds seem to wear a raincoat. Think of the waxy sheen on lambsquarters or the hairy texture of marestail that causes spray to just roll off. This is where a heavy-duty, petroleum-based crop oil like Drexel Pen-A-Trate II earns its keep.
This isn’t your everyday, all-purpose adjuvant. It’s a specialized tool designed to help herbicides penetrate the toughest targets. Its blend of paraffinic oil and surfactants is particularly effective at breaking down those natural defenses, ensuring your herbicide makes contact and gets absorbed. If you’re dealing with a persistent weed that has shrugged off previous applications, adding this to the tank can be the difference between failure and success.
The power of Pen-A-Trate II comes with a caution, however. Because it’s so effective at penetrating leaf cuticles, it can increase the risk of crop injury (phytotoxicity), especially on sensitive plants or during hot, humid weather. Use it when you have a specific, tough problem, not as your default for a general foliar feed on your tomatoes.
Southern Ag MSO for Faster Nutrient Uptake
When you need to correct a nutrient deficiency fast, a Methylated Seed Oil (MSO) is your best friend. Southern Ag’s MSO is a prime example of this "hotter," more aggressive type of adjuvant. Derived from vegetable oil, it’s exceptionally good at dissolving the waxy cuticle of a plant leaf.
This rapid penetration is exactly what you want when your plants are screaming for help. Imagine your pepper plants showing the tell-tale signs of a calcium deficiency, leading to blossom-end rot. A foliar spray of calcium chloride mixed with an MSO can get that nutrient into the plant system much faster than a standard crop oil, potentially saving the next round of fruit.
That speed comes with a tradeoff. MSOs carry a higher risk of causing leaf burn, especially when used on hot, sunny days or on tender new growth. The very thing that makes it work so well—dissolving the plant’s protective layer—can also damage it if conditions aren’t right. It’s a high-performance product that demands you pay close attention to the weather and your application rates.
Monterey Herbicide Helper for All-Around Use
Sometimes you don’t need a specialized tool; you need a reliable multi-tool. Monterey Herbicide Helper is that dependable, all-around crop oil that works well in a wide variety of situations without being overly aggressive. It’s a petroleum-based COC that provides excellent spreading and sticking capabilities.
This is the kind of product you reach for when doing a general-purpose spray. Whether you’re applying a selective herbicide to your lawn or giving your squash plants a mid-season boost of liquid kelp, it ensures good coverage and absorption. It strikes a great balance between effectiveness and crop safety, making it a solid choice for those of us managing a diverse set of plants.
Think of it as the perfect middle ground. It’s more effective than a simple non-ionic surfactant but not as risky as a potent MSO. For a hobby farmer who needs one reliable product on the shelf to handle 80% of their needs, this is an excellent starting point.
Hi-Yield Crop Oil: A Dependable Classic
There’s something to be said for predictability. Hi-Yield Crop Oil is a no-frills, straightforward paraffinic oil concentrate that has been a staple in sheds and barns for decades. It does exactly what it’s supposed to do—help your sprays stick and penetrate—without any surprises.
This is the product you use when you have a system that already works. You’ve been using the same post-emergent on your sweet corn patch for years, and you know precisely the results to expect. Hi-Yield provides that consistent performance, ensuring your trusted formulas work the way they always have. It’s affordable, widely available, and effective.
It may not have the rapid-action punch of an MSO or the specialized power of a high-surfactant blend, but its reliability is its greatest strength. It’s a testament to the "if it ain’t broke, don’t fix it" philosophy that serves small farmers so well.
Neptune’s Harvest Oil for Organic Growers
For those of us farming organically, the options can feel limited. While you wouldn’t mix a synthetic herbicide, you still need your organic sprays to work effectively. Neptune’s Harvest Hydrolyzed Fish Oil serves this purpose beautifully, acting as a natural sticker-spreader for a variety of organic inputs.
This isn’t a traditional crop oil concentrate designed to potentiate herbicides. Instead, it’s a cold-pressed fish oil that helps organic fungicides (like copper or sulfur), insecticides (like neem oil or pyrethrin), and foliar feeds (like liquid kelp) adhere to plant leaves. It prevents these valuable sprays from simply washing away in the next rain or dew.
The best part is its dual function. Beyond being an excellent adjuvant, the fish oil itself provides nutritional benefits to the plant and soil microbes. It’s a synergistic product that enhances your spray’s effectiveness while contributing to the overall health of your garden. It’s the perfect choice for an organic system where every input should serve multiple purposes.
Mixing Ratios and Application Best Practices
Getting the oil right is only half the battle; mixing and applying it correctly is just as important. The absolute first rule is to read the label on both your crop oil and the product you’re spraying. The manufacturer’s recommendation is your best guide.
As a general rule of thumb, most crop oil concentrates are mixed at a rate of 1% by volume. This is easy to calculate: for one gallon of water (128 ounces), you’ll add about 1.25 ounces of crop oil. For a 3-gallon backpack sprayer, that’s around 4 ounces. Always use a dedicated measuring cup.
The order you mix things in matters. A good practice is to fill your sprayer halfway with water, add your nutrient or herbicide and agitate it well, and then add the crop oil last as you top it off with the remaining water. This prevents clumping and ensures everything is properly emulsified.
Finally, timing is everything. Spray in the cool of the early morning or late evening. Applying any spray, especially with an oil, in the heat and direct sun of midday is a recipe for scorching your plants. If you’re ever unsure about a new combination, test it on a small section of your crop and wait a day or two to see how the plants react.
Choosing the Right Oil for Your Specific Crop
There is no single "best" crop oil. The right choice depends entirely on your goal, your crop, and the conditions. It’s a constant balance between effectiveness and safety.
Here’s a simple framework to guide your decision:
- Tackling tough, waxy weeds? You need a powerful penetrant. A petroleum-based product with high surfactant content like Drexel Pen-A-Trate II is built for this job.
- Need to deliver nutrients fast? An MSO like Southern Ag MSO will get the job done quickly, but you must be mindful of the increased risk of crop burn.
- Looking for a reliable all-rounder? A balanced petroleum oil like Monterey Herbicide Helper or the classic Hi-Yield Crop Oil is a safe and effective choice for most common tasks.
- Farming organically? A natural fish oil like Neptune’s Harvest is your go-to for improving the performance of organic-approved sprays while adding nutritional benefits.
Ultimately, your decision comes down to risk versus reward. The more aggressive the oil, the more effective it is at penetrating the leaf, but the higher the potential for damaging your crop. Always start with the gentlest option that can get the job done, and only move to a "hotter" product when the situation truly demands it.
Adding the right crop oil is a small, inexpensive step that dramatically improves the return on your investment of time and money. It ensures the products you spray actually get where they need to go. It’s a classic example of working smarter, not harder, to get the results you want from your land.
