ARS | Publication request: RESPONSES OF SPRING WHEAT CULTIVARS TO NUTRIENT SOLUTIONS CONTAINING ADDITIONAL POTASSIUM CHLORIDE

Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 11, 2005
Publication Date: March 22, 2006
Citation: Evans, K.M., Riedell, W.E. 2006. Responses of spring wheat cultivars to nutrient solutions containing additional potassium chloride. Journal of Plant Nutrition 29:497-504.

Interpretive Summary: Adding chloride fertilizer to low chloride-testing soil results in a positive yield gain 70 % of the time. These yield responses in hard red spring wheat are often cultivar specific. In a low chloride-testing soil, some cultivars show up to a 20% yield increase in certain cultivars while others are unresponsive. The physiological basis for the different cultivar responses to chloride fertility is not understood. The dynamic nature of dominant cultivars in specific agricultural regions make cultivar interactions exceedingly difficult to manage unless the fundamental cause of the cultivar-chloride fertilizer interaction is understood. 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 research reported here measured the chloride response of different hard red spring wheat cultivars under controlled environments. This information will be useful in future experiments designed to look at the impact of chloride nutrition on spring wheat 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 spring wheat cultivars to increase yield.

Technical Abstract: Hard red spring wheat (Triticum aestivum L.) cultivars respond differently to chloride fertilizer under field conditions. The objective this research was to investigate cultivar-specific chloride responses under controlled environments. Plants were grown in sand culture with +/- additional chloride (+/- 20 mM KCl) nutrient solutions or with different levels of chloride (0, 20, 80, 160 mM KCl) for four weeks. Of cultivars given additional chloride, 'Butte', 'Sharp', 'Ingot', 'Oxen', 'Forge', and 'Ember' had significantly greater shoot chloride response than 'Marshall'. 'Butte' had a lower initial chloride concentration than 'Marshall' (at the 0 KCl treatment level), but at other KCl treatment levels (20, 80, 160 mM), 'Butte' had higher leaf chloride levels than 'Marshall'. In soil-grown plants given 0, 20, 80, 160 mM KCl from planting to heading, seed number remained constant while individual seed weight and total yield decreased at higher KCl treatment levels in 'Butte'. Individual seed weight remained constant while seed number and total yield increased in 'Marshall'. We conclude that chloride fertilizer response in 'Marshall' seen under field conditions may be mediated by reduced chloride uptake which in turn resulted in decreased chloride toxicity at higher chloride soil fertility levels.