Foliar Feeding Season
Late May and early June generally kicks the foliar feeding season into high gear. GMS is applied: shortly after first cutting hay; when corn is close to knee high-V6 to V9-growth stage; and to early reproductive vegetable plants. So this is the time of year Growers Chemical Corporation needs to remind producers about the protocols of foliar feeding.
The protocols discussed by Growers Chemical Corporation in the past have remained relatively consistent and that is fine for most of the foliar feeding protocols. However, the water chemistry discussion, which is more complex than the other procedures, needs some increased scrutiny.
UNDERSTAND WATER CHEMISTRY
It is not necessary to add water to GMS when foliar feeding. However, for convenience and to accommodate the spray tips in their sprayers, most producers do use some water dilution when foliar spraying the crop with GMS, especially at lower rates (1 to 2 gallons per acre).
If the water volume mixed with GMS is less than the volume of GMS, water quality is important only if particulate matter (dirt) is present in the water. However, whenever the volume of water exceeds the volume of GMS in the spray solution, it is very important the dissolved solid level, or hardness, of the water be addressed. Water containing certain levels of dissolved solids has to be acidified. Otherwise it may chemically interact with the GMS and impair the success of the GMS on the sprayed crop.
Making sure the water does not react with the GMS helps the GMS work properly in the plant tissue and also ensures there are no physical spraying (plugging) problems from crystal accumulations.
Photograph A included in this edition of The Growers Solution shows the difference in dissolved solid precipitation for various water sources. Usually the lower the dissolved solid content of water, the less mineral precipitation occurs with the water when mixing with GMS. Even though this precipitation can be prevented using various chemical additions (acidifiers), those accumulated minerals are still present in the final mixed solution. What that means is even though those accumulated minerals can be kept dissolved in the spray solution, once they are applied to the plant tissue they may precipitate out into a dry form that covers the plant tissue. If that dry form is concentrated enough, it could coat the plant leaves enough so that there is interference with photosynthetic activity.
The best way to visualize this problem is visualizing the amount of dried material that will result on the leaves of the 3 solutions show in Photograph A. Well water will deposit more dry minerals on the plant leaves than rain water. That is why research work is showing that the success of foliar spraying of GMS is improved by lowering the amount of dissolved solids in water that is used to spray GMS. For example, some farmers are collecting rain water to replace their well water for spraying with GMS.
PRECAUTIONS
As the new age of genetic modification brings old herbicides to new uses for weed control, it is very important for producers to follow proper protocols. With the use of glyphosate style chemistries (Roundup® or Liberty®), it is very important to clean sprayers thoroughly before spraying sensitive crops with GMS in those same sprayers. This is even more important with new GMO's (genetic modified organisms) using Dicamba and 2,4-D chemistries. Crops that are not genetically modified to withstand the Dicamba or 2,4-D chemistries can be very sensitive to very small amounts of these compounds. Producers using these new modifications must understand these sensitivities and follow proper tank washing procedures before spraying sensitive crops. The importance of following cleanliness with sensitive chemistries cannot be over emphasized.
SPRAY USING A FINE MIST
In order for spray particles to penetrate the small, minute holes in the plant's cuticle, it is best the plant leaves be covered, as much as possible, with a fine spray mist having physically very small particles. Achieving the best coverage and smallest particle size usually requires higher spraying pressures. When spraying GMS, pressures over 40 psi tend to create smaller particle sizes. If drift is a concern when foliar spraying, tend toward the highest pressures recommended for the type nozzle being used. Foliar feeding with minerals (elements) is similar to spraying a fungicide in that the plant needs as much coverage as possible with small particles sizes.
DO NOT SPRAY IN THE HEAT OF THE DAY
The cuticle (skin or covering) of the plant leaf has a lot of openings which allow moisture to penetrate into the leaf and its internal cell structure. Any minerals (elements) dissolved in the moisture penetrating the plant's cuticle become part of the internal structure of the plant and help plant growth. Foliar feeding is the most successful when applied to plants which have accumulated some moisture on their leaf surfaces. Growers Chemical Corporation suggests producers foliar spray late in the evening; early in the morning; on overcast foggy days; or when the leaves have, or will shortly have, some dew moisture on them which will help the minerals contained in the GMS be dissolved into the water and then the water is absorbed by the plant.
STRAIGHT or WITH LITTLE DILUTION
Foliage spraying Growers Mineral Solutions straight, without water dilution, shouldn't be considered a "forgotten art," at least not yet. It was the rule, not the exception, in the early years of Growers Mineral Solutions. Chances are, though, many newer Growers customers haven't yet considered the option.
Most present day spraying is done at spray rates of about 10 to 20 gallons per acre to facilitate herbicide, fungicide, or insecticide spraying. When GMS is added to these high gallon mixes, hard water issues sometimes appear. GMS and hard water often do not combine well. The phosphorus in Growers and the calcium in the hard water tend to form a milky mixture in the spray tank. The fallout makes some of the beneficial nutrients in the Growers not available to feed the crop as intended. Also, mechanical problems sometimes occur, such as spray tip and screen plugging.
Hard water does not always cause problems, especially when the mix ratio is in the one part water, one part GMS range. This means the producer could effectively double his spray rate from 2 to 3 gpa to 4 to 6 gpa and still not encounter hard water issues. But staying with the lower spray rates means less frequent time consuming stops to refill the spray tank.
Avoiding the hard water problem altogether, many Growers customers spray their GMS as the recommended rates, straight, without dilution. This is done with low volume spray tips available from Growers and most ag equipment suppliers.
MIXING WITH OTHER PRODUCTS
Excellent results can be expected when the product is used in accordance with Growers' Recommendations for Using. Poor results can be expected if Growers Mineral Solutions is used with any material other than uncontaminated water in the application. Nothing expressed or implied shall change the Growers Recommendations for Using when the Growers product is used in conjunction with the product of another manufacturer regardless of other manufacturer's recommendations.
Farm operators foliar feeding GMS for the first time, and to ensure success, should use their GMS sales representatives as a knowledge resource.
This is an excerpt from the Summer Growers Solution (2019) written by Jim Halbeisen, Director of Research.
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