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Plant Tissue Analysis -- A Useful Diagnostic Tool to Determine the Health of Plants
Is your fertility program meeting the crops nutritional needs? A soil test indicates a soil’s likely nutrient supplying capacity. However, environmental conditions and soil factors such as compaction affect the actual supply of nutrients available to a plant – this is often more or less than that predicted by a soil test. Plant tissue analysis (plant analysis) is a diagnostic tool that measures the level of specific nutrients in a plant. Plant analysis may be used to determine the actual level of nutrients taken up by a crop versus those predicted by a soil test.
The plant nutrient concentrations are then compared to standardized values for specific growth stages and plant parts. Since plant nutrient concentrations change during a growing season, it is imperative that sampling follows standardized procedures for growth stage and the plant part. UMC Guide G9131 Sampling Plant Tissue and Soil for Analysis provides instruction for proper collection, care and shipping plant samples for a variety of crops.
While symptoms for individual nutrient deficiencies are typically distinctive, a precise diagnosis may not be possible until a plant analysis is conducted. Nutrient deficiencies can be confirmed or rejected through the use of plant analysis.
When sick looking plants appear a paired sample technique may be used. Using this technique, paired samples are collected — one from sickly appearing plants and the other from nearby healthy plants. The healthy plant sample provides a comparison against which sick plants can be judged.
In addition, plant analysis can be used to determine non-visual crop nutrient deficiencies. Plants typically do not exhibit nutrient deficiency symptoms until severely deficient. Before such symptoms are exhibited, plants can suffer from “hidden hunger” in which yield-limiting nutrient uptake is being experienced.
The desired nutrient concentration requirements of crops are well established for their different growth stages. Thus a crop’s nutrient status can be monitored throughout the season. If the crop begins to approach a deficiency, then corrective measures can be taken.
Plant analysis need not be limited to the growing season. Some plant analyses can be considered post-mortem tests in which plant tissue from the crop residue or grain are analyzed to determine if a nutrient was deficient.
The University of Missouri Soil Testing Laboratory does plant analysis as one of its services. Forms can be obtained and samples submitted through local extension centers. Click here to view the lab's web site.
(Author: Todd Lorenz, Horticulture/Agronomy Specialist)
The Soybean Aphid May Be Coming to a Field Near You
Last year a new soybean pest arrived in Missouri. Infestations were found from Michigan to Wisconsin and south into Kentucky and Tennessee and over to Missouri. The greatest numbers were found in Michigan and Illinois. No other aphid infests soybean. The coming season will tell us how successfully this new pest over-wintered.
The soybean aphid is a small, light green or yellow aphid, which can infest soybean as soon as the plants emerge. (Click here to view images of aphids.) Currently, most of the information on soybean aphid comes from overseas research. China is a major source of this information and how much of it is directly applicable to Missouri is not known.
The earlier in the season an infestation starts, the more serious the potential for crop injury. Unfortunately, there are no economic thresholds established as yet for soybean aphid numbers nor are any pesticides labeled for the pest. Timely scouting of soybean fields should still be conducted to monitor the status of this pest. Suspected soybean aphid infestations should be reported to local extension centers. This information can then be used by the University of Missouri and the Missouri Department of Agriculture to determine the need for emergency aphid pesticide labeling.
Damage to the soybean plant occurs when aphids suck plant sap and the excess water and carbohydrates (sugars) are expelled as a material called "honey dew" (a very descriptive name). Fortunately, they do not inject a toxin during feeding. When high numbers are on infested plants, the amount of honeydew is large enough to literally drip. Chinese researchers report this feeding can cause a 27 percent yield reduction and significant stunting. Last year, heavily infested fields in Michigan and Illinois were stunted. The leaves in these fields were wrinkled, cupped and had yellow margins.
Throughout the growing season, soybean aphids are all females and produce all live females young. This gives them the potential to build serious infestations quickly. Soybean aphids have a few hosts plants (soybean, buckthorn, tick clover "sticktights", and kudzu). At the end of the growing season, male aphids are produced, mating occurs and over-wintering eggs are laid on buckthorn.
Think about these points if an infestation is found on your farm:
(Author: James Jarman, Agronomy Specialist)
Two major potential drawbacks of gifting are:
Benefits of gifting:
Given the substantial benefits of gifting and the potential disadvantages, the following strategies might be appropriate:
Estate planning offers the opportunity for tremendous tax savings and the ability to draft a customized plan to meet your goals and objectives. However, to minimize the potential of costly litigation and disputes among the heirs, a professional estate planner should be involved in the drafting or at least a review of your plan.
(Author: Parman Green, Farm Business Management Specialist)
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Missouri Value Added Development Center
The Missouri Value Added Development Center offers a look at innovative ways producers are enhancing profitability and simultaneously maintaining the agricultural base for sustaining rural communities. An end-user driven 21st century agriculture will provide opportunities for small farms through marketing high value commodities and commercial farms through directly integrating into the global food supply chain. Collective organization of producer groups will be a key to the development of small and commercial scale agricultural operations. The center has a key focus on helping those interested in value added ventures in the area of business development.
Dr. Joe Parcell is the director of the Missouri Value Added Development Center. This center is home to the UOE Agricultural Business Counselors network. The Agricultural Business Counselors (ABCs) are a source of 35 University persons trained in business development and business leadership skills. The ABCs serve three primary roles as an initial contact person, as an informational point of contact, and as value added educator.
In Central Missouri, your ABC’s are Melvin Brees, Farm Management Specialist, Howard County; Don Day, Agricultural Engineer and Information Technology Specialist, Boone County; Tim Schnakenberg, Agronomy Specialist, Morgan County; Mark Stewart, Livestock Specialist, Callaway County. If you need value added business development assistance, then we can help you. Click here to view the Missouri Value Added Development Center website.
(Author: Mark Stewart, Livestock Specialist)
Ag Connection - Ag Connection Newsletter, June 2001