Submitted to: The Sunflower
Publication Type: Popular Publication
Publication Acceptance Date: April 30, 1999
Publication Date: June 10, 1999
Interpretive Summary: Farmers in the central Great Plains require basic information regarding the agronomy of sunflower to help them in making the transition to growing this new alternative crop. This article describes the water use/yield relationship, water sensitive growth stage, and soil water extraction pattern of sunflower. Additional, the effect of sunflower on subsequent wheat and millet yields grown in rotation with sunflower is quantified. This information will benefit farmers in determining how sunflower will respond to their local rainfall conditions. They will be able to make an informed decision regarding how and if sunflower can be used to diversify their agricultural operation.
Technical Abstract: Sunflower is an alternative crop suited to the environmental conditions of the central Great Plains. This article defines for sunflower the water use/yield relationship, water sensitive growth stage, soil water extraction pattern, and impact on subsequent crop yield. Sunflower yield increases by about 150 lb/a for every inch of water use after the first 7 inches of water use. Sunflower is most sensitive to water stress during the period just prior to flowering through seed development. Sunflower's extensive and deep root system typically extracts 7.5 inches of water from the top six feet of the soil profile. On average, wheat yields in a wheat- sunflower-fallow rotation are 30% lower than wheat yields in a wheat-corn- fallow rotation. Millet yields in a millet-sunflower rotation average 50% lower the millet yields in a millet-wheat-corn rotation.