Premium
Simulating Yield Losses in Grain Sorghum due to Sorghum Downy Mildew 1
Author(s) -
Tuleen D. M.,
Frederiksen R. A.
Publication year - 1981
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1981.00021962007300060018x
Subject(s) - sorghum , downy mildew , sowing , agronomy , yield (engineering) , crop , biology , grain yield , population , mathematics , physics , demography , sociology , thermodynamics
Reliable estimates of potential losses to disease enable growers to profitably manage crops. Simulation models can give unbiased loss estimates as well as determine research areas critical to the understanding of host‐parasite interactions. A model is presented for calculating yield loss in grain sorghum [ Sorghum bicolor (L.) Moench] due to systemic sorghum downy mildew caused by Peronosclerospora sorghi (Weston & Uppal) Shaw. It is sensitive to plant population, disease reaction of the hybrid, and rainfall following planting. The model was developed using data sets from field experiments conducted over several years in South and Central Texas. Empirical data indicate that: 1) a low incidence of systemic infection can thin dense sorghum stands to an optimum plant density and allow healthy plants to prosper, 2) genetic resistance effectively reduces grain yield losses caused by the disease, and 3) rainfall within 4 to 7 days after planting is associated with a low incidence of sorghum downy mildew at the locations observed. Model estimates were plotted against measured crop yields using seven data sets (from field tests conducted in 1975 and 1979 at two South Texas locations). Multiple regression analysis performed on the data showed that the model simulated grain yield with acceptable precision.