CHLORIDE RESPONSE OF SPRING WHEAT VARIETIES

Authors: EVANS, K - STUDENT; Riedell, Walter

Submitted to: Soil/Water Research, Progress Report
Publication Type: Experiment Station
Publication Acceptance Date: 1/31/2003
Publication Date: 4/30/2003
Citation: EVANS, K.M., RIEDELL, W.E. CHLORIDE RESPONSE OF SPRING WHEAT VARIETIES. SOIL/WATER RESEARCH, PROGRESS REPORT. 2003. v. 02. p. 42-44.

Interpretive Summary: Chloride is mobile in the soil profile and many well-drained soils in northeast and north central South Dakota are low in this essential plant nutrient. Chloride fertilizer added to low (less than 30 lbs/acre, 2 foot sample) chloride-testing soil results in a positive yield effect 70 percent of the time. Positive yield responses of hard red spring wheat to chloride fertilization are often variety specific. The physiological basis for the chloride varietal response is not understood. Perhaps optimal chloride nutrition increases yield by eliminating chloride deficiency or by suppressing crop disease. Because soil fertility and disease suppression are among the most important management tools used by farmers, additional research on the physiological basis of the chloride effect is needed. The objective of the research reported here was to measure the chloride response of different small grain varieties under controlled environments. This information will be useful in future experiments designed to look at the impact of chloride nutrition on small grain diseases (e.g. scab and rust) and may also be useful to farmers who are interested in using a chloride fertilizer program in conjunction with specific small grain varieties to combat small grain diseases and increase yield.

Technical Abstract: The objective of the research reported here was to measure the chloride response of different small grain varieties under controlled environments. Three greenhouse experiments were conducted in which nutrient solutions containing different levels of chloride were applied to different varieties of hard red spring wheat. Chloride was extracted from plant tissue and measured using the ferric nitrate/mercuric thiocyanate colormetric method. Data were analyzed using PROC GLM in SAS software. Multiple range testing (Duncan's) of chloride response were calculated for each variety. We observed varietal differences in the chloride response under greenhouse conditions. The variety `Marshall' absorbed less chloride and had greater yields in response to chloride treatments than other spring wheat varieties measured. These results are similar to those of previous studies that found that `Marshall' spring wheat had increased yield in response to chloride fertilizer applications to low chloride-testing soil under field conditions. Perhaps the chloride fertilizer response in `Marshall' seen under field conditions was mediated by reduced chloride uptake which in turn resulted in decreased salt injury at higher chloride soil fertility levels.