by Tim Payne, Gainesville Camellia Society, The Camellia Journal • September - November, 2005
My ongoing quest for the perfectly healthy camellia led me to visit my Valdosta, Georgia neighbor, ACS President Hulyn Smith. I could not help but notice the deep, rich green of his plants. I also noted the relative absence of disease and insect damage. I asked him to what he credited his impressive results, and he replied, “KeyPlex®.” “I spray it on all my plants several times per year”, he continued.
I soon called another camellia expert, Mark Crawford, Chair of the ACS Research Advisory Committee. Mark assured me foliar feeding was a highly efficient method of improving camellia health. He told me that Jerry Conrad, of Erinon Nursery in Florida, and he had used KeyPlex with great results for several years. A recommendation from these three eminent growers seized my attention. I hurried to research KeyPlex and foliar feeding.
Foliar feeding is the application of plant nutrients and other supplements to the plant parts that are above the ground. The purpose of foliar feeding is not to replace soil fertilization but to complement it. Foliar applications have proven a quick acting method of supplying secondary nutrients and micronutrients, while also supplementing N-P-K at critical growth stages. Plants can absorb nutrients through the stomata located primarily on the undersides of the leaves. However, absorption can also occur via the epidermal cells of leaves and to some extent bark. According to Crawford, research has shown that plants can utilize foliar-fed urea as a nitrogen source with a minimal use of energy. In addition, urea is so readily absorbed that it aids in the plant’s absorption of other supplements like those found in KeyPlex.
Research data show that the combination of KeyPlex, summer oil, and slow release nitrogen (such as found in some types of urea) used in multiple applications can produce a synergetic result that allows enhanced uptake of the nitrogen and micronutrients. Improved control of fungi and pests such as mites is also abetted.
Morse Enterprises Limited Inc., manufactures KeyPlex in a variety of formulae. All of the KeyPlex products contain yeast extract hydrolysate from Saccharomyces cerevisiae. KeyPlex is labeled for agricultural crops, citrus, turf, and ornamental plants to prevent plant diseases. It has been marketed as a micronutrient for 20 years and is used extensively in the citrus industry.
Proteins that signal invasion by a disease or attack by an insect can trigger immune systems in some plants. Based on research by the USDA, KeyPlex works to control pests by jump-starting the plant’s natural defenses.
Foliar feeding also benefits camellia roots resulting in a deeper, more fibrous root system. This in turn allows enhanced nutrient availability. Since KeyPlex has some fungicidal activity, less soil borne disease can result.
Foliage applications promote plant health by both inducing a Systemic Acquired Resistance (SAR) response in the plant and increasing the uptake of elemental nutrients through the leaves. SAR is the activation of defenses in healthy parts of a plant. As a result, the entire plant is more resistant to a secondary infection. Once established, SAR can enhance resistance to a variety of camellia problems over time. The net result of multiple foliage applications is a healthier, faster growing camellia better prepared to resist diseases, pests, and environmental stresses.
Not all fertilizers are suitable for use as a foliar spray. The primary objective of a foliar application is to allow for maximum absorption of nutrients into the plant tissue; therefore, foliar fertilizer formulations should meet certain standards in order to avoid damage. The experts at Morse recommend N-Sure®, a 28-0-0 liquid urea product manufactured by Tessenderlo Kerley. This product contains approximately 8% standard urea nitrogen and approximately 20% slower release, soluble triazone urea.
|Please note: Brand/trade names, distributors, and treatment protocols are provided for information and reference only and should not be considered as an endorsement by the author or the American Camellia Society (ACS). |
Consult your State Agricultural and Pesticide agencies for recommended chemicals registered in your State. Always follow instructions on the label. We recommend the use of latex or vinyl gloves, safety glasses, and respiratory protection as a minimum while using these chemicals and compounds. Recommendations are developed from actual experience and from sources believed to be reliable. Neither the author nor the ACS imply or express any warranty or assume liability for the recommendations’ use or misuse.
The following suggestions may help assure an effective foliar feeding program:
- While water chlorination removes harmful bacteria, it also kills beneficial organisms, which may be included in, or encouraged by, foliar feeding. I use rainwater whenever possible, collecting it in buckets and cisterns. Considerable chlorine can be removed from tap water by letting it stand in an open container overnight;
- Dilute solutions of nutrient formulations are suggested. My experience has shown that a 1:250 ratio of KeyPlex to spray water is adequate. This equates to about 2 teaspoons (10 ml) of KeyPlex per gallon. KeyPlex researchers report that even less, a ratio of 1:400, is effective. When using N-Sure, I limit the amount to 4 teaspoons (20 ml) per gallon of water. My final additive is Ultra-Fine oil at a rate of 2 tablespoons (30 ml) per gallon;
- The pH of your spray solution should remain in the neutral range (6.0-7.5). Therefore, avoid soluble fertilizers labeled for acid-loving plants. It is also important to avoid fertilizers with high phosphorus and/or potassium content such as 20-20-20 or 20-10-20, according to the researchers at Morse;
- Superior absorption is achieved when foliar sprays are finely atomized. This can be accomplished by increasing your sprayer pressure or by using a mist blower. It is especially important to spray when wind is minimal because finely atomized sprays drift. I use a 5- gallon capacity Solo pump-up sprayer. This handy device employs an articulated spray cone on an extending wand that is easy to aim;
- For best effect, spray when air temperatures drop to 70-78° F. Stomates are closed at higher temperatures and absorption is decreased. My most effective foliar feeding has been late in the evening or in the early morning when the wind is still, and temperatures are in the target range. Absorption is further enhanced when the weather is humid, thereby slowing the drying time of the spray residue.
- Spray all areas of the camellia until runoff is observed, paying particular attention to the undersides of the leaves;
- I schedule at least four applications of the KeyPlex/N-Sure/Ultra-Fine oil mixture each year. I spray at spring bud break and again in mid-June when I observe a second flush. My third spraying is in September when I observe the final growth flush of the season. My final scheduled application is in early November prior to the major bloom season for japonicas. However, I often spray individual plants that are lagging or suffering from disease or pest attack whenever the spirit moves me. I do limit treatment to a maximum of six foliar feedings per year in all cases.
KeyPlex and N-Sure are available from United Agriculture Products (UAP) in Waverly, Florida. UAP’s telephone number is: 863.439.1569. KeyPlex® is a registered trademark of Morse Enterprises Limited, Inc., Miami, FL. N-Sure® is a registered trademark of Tessenderlo Kerley, Inc., Phoenix, AZ.
This article is published on this site with the permission of the American Camellia Society © 2005-09