Inter- and Intra-Plant Competition. (3803)
Authors:
E.D. Nafziger* - Univ. of Illinois
Abstract:
The degree of interplant competition is affected by distance between plants and uniformity of size and vigor of adjoining plants. Our data indicate that, at normal densities, individual plant yield is not closely related to the amount of space that plant occupies in the row, or to position of that plant within its space. Plants lose about 1 % of yield for each day of planting delay compared to adjoining plants up to 10 d, and this loss accelerates to about 1.5 % per d for plants planted 10 to 20 days later than their neighbors. Yield compensation by early-planted plants with delayed, adjoining plants is incomplete. The ability of plants to respond to changes in competition decreases with age. In one study, plants increased per-plant grain yield about 3 percent less for each vegetative stage later that their two neighboring plants were removed, from increasing per-plant yield by 81 percent when thinned at V4 to only 46 percent when thinned at V16. Intra-plant competition refers to
internal allocation of resources, and involves complex interactions among plant parts, as well as overall photosynthate supply. Yield loss per plant accelerates as defoliation is delayed, to complete failure of pollination when defoliation occurs at the end of vegetative growth. Allocation of scarce resources involves tradeoffs among stalks, roots, and grain, and is affected by plant density.
Speaker Information: Emerson Nafziger, Univ. of Illinois, Crop Sciences 1102 South Goodwin, Urbana, IL 61801; Phone: 217.333.4424; E-mail: [email protected]
Session Information: Tuesday, November 2, 2004, 8:30 AM-12:05 PM Presentation Start: 9:20 AM
