Recognizing Nutrient Deficiency Symptoms
Sunday, April 1, 2001
filed under: Fertility
Recognizing Sunflower Nutrient Deficiency Symptoms
A sunflower nutrient deficiency symptoms chart was developed by Colorado State University as an educational tool for farmers and consultants. Just as people learn to scout for pests, they should also be scouting for nutrient deficiencies, says Jessica Davis, CSU extension soils specialist.
Davis says the chart should be accurate anywhere sunflowers are grown, since the physiology of the plant doesn't change. However, deficiencies may differ by soil type, and soil pH.
North Dakota State University extension soils specialist David Franzen says that as long as he has been on the job in North Dakota, nitrogen deficiency is the only nutrient deficiency problem he has seen in sunflower. The crop is very tolerant to conditions that cause chlorosis in soybeans due to iron, and its response to phosphorus is generally not as large as can be seen in small grains. Sunflower in North Dakota is also relatively tolerant to low potassium levels, he says.
Soil sampling is the key to catching nutrient deficiency problems before they start. For more how-to information on soil sampling, see the NDSU extension publication, “Soil Sampling as a Basis for Fertilizer Application,” (Bulletin SF-990, revised in August, 1998) by David Franzen and fellow soil scientist Larry Cihacek. The publication can be found on the Internet at http://www.ext.nodak.edu/extpubs/plantsci/soilfert/sf-990.htm