β Scribed by R.L. Pitter
No coin nor oath required. For personal study only.
The influence of weather on wheat yields in Oregon is characterized by multiple curvilinear regression analysis. Technological advances are also characterized in the analysis. Synergistic heat-moisture stress is characterized by a modified precipitation-temperature parameter, and a representation of soil moisture at planting time is introduced to characterize the "timely rains" which Eastern Oregon wheat growers desire. Standard deviation of error between estimated and actual yields was 2.35 bu/a. The inftuence of weather was investigated by holding technology at a constant level, and was found to be +-5 bu/a in extreme years. No systematic effect of global warming and cooling trends was identified. Model validity was substantiated by comparison of results with an independent data set.
π SIMILAR VOLUMES
Corn and soybean yields on Allerton Trust Farms, Piatt County, Illinois for the period 1950--1976 are studied. Statistical analyses indicate that the description of yield increases by linear trend equations could not be significantly improved by use of various non-linear trend formulations. The adeq
Lin, Kuang-hsing T. and Seaver, S.K., 1981. Influence of weather and technology on corn and soybean yield trends --comment. Agric. Meteorol., 23: 169--174. Recently Swanson and Nyankori (1979) reported regression results for corn and soybean yields collected from well-managed University of Illinois