Yield potential in modern wheat varieties: its association with a less competitive ideotype uri icon

abstract

  • Field experiments were conducted with modern semidwarf spring wheat cultivars representing a range of yield potential in order to compare their adaptation to levels of interplant competition for resources. Levels of competition were altered, in both leaf canopy and underground, by manipulating rows of plants in eight-row yield plots. Competition for light was decreased by bending adjacent rows away from the central two rows thus permitting greater penetration of light to lower leaves of the central rows (light treatment). Reduced competition underground was realized, simultaneously with reduced competition for light, by uprooting the plants adjacent to the central two rows (root/light treatment). These treatments were implemented at the developmental stage of flag-leaf ligule emergence (FLLE), when interplant competition was assumed to become maximal. While the average yield responses were 25%, and 40% to the light and root/light treatments respectively, there was a significant interaction with genetic material. Low-yield-potential(LYP) lines responded more to reduced competition than high-yield-potential (HYP) lines suggesting that the greater efficiency of the HYP lines, reflected in their higher yield, is related to their better adaptation to interplant competition. Physiological bases for improved performance are examined and discussed in relation to ideas about crop ideotypes and possible implications to breeding. These data appear to support the idea that genes conferring yield potential through improved adaptation to the crop environment are associated with a less competitive phenotype.

publication date

  • 1994
  • 1994