Fig 1.
Spatiotemporal use patterns of the soybean seed-applied fungicides in the United States.
(A) state-wide use of total seed-applied fungicides across nine years (2006 to 2014); (B) total seed-applied fungicide use between 2006 and 2014 by region (Northern states = Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Nebraska, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin; Southern states = Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and Virgina. Fungicides included: fludioxonil, mefenoxam, and metalaxyl). Temporal fluctuation of the (C) the total seed-applied fungicide use, (D) fludioxonil, mefenoxam, and metalaxyl use across 28 states between 2006 and 2014.
Table 1.
National scale mixed-effects regression modelling of the effect of seed-applied fungicide use on soybean production/yield losses due to seedling diseases from 28 soybean growing states in the United States during the time period between 2006 and 2014.
Table 2.
National scale mixed-effects modelling of the effect of seed-applied fungicide use on soybean production/yield from 28 soybean growing states in the United States during the time period between 2006 and 2014.
Fig 2.
Comparison of the mean per hectare seed-applied fungicide use (in g) among yield/harvest/production zones.
Within each zone type, means followed by a common letter are not significantly different after adjustment for multiple comparisons using Tukey-Kramer test at the 5% level of significance. Error bars represent standard errors. The fungicides included: fludioxonil, mefenoxam, and metalaxyl. The selected fungicides are effective against Fusarium wilt, Phytophthora root and stem rot, and seedling diseases caused by Fusarium, Phomopsis spp., Pythium, and Rhizoctonia solani.
Fig 3.
Factor maps generated through factor analysis of mixed data (FAMD) approach showing the variance maximizing distribution pattern of data points (n = 252) in the map space with their clustering patterns based upon region (n = 2), and yield/harvest/production zones (n = 4 in each case).
Yield/Harvest/Production zones = represent four levels (zone 1 to 4) based on the quartiles within a database containing 252 yield (kg/ha)/harvest area (ha)/production (MT) data points (252 = 9 years × 28 states). Within this database, data points from the minimum to the first quartile were classified as zone 1. Similarly, data points from the first quartile to median, median to the third quartile, and > third quartile were respectively classified as zones 2, 3, and 4. Fungicides included: fludioxonil, mefenoxam, and metalaxyl which are effective against Fusarium wilt, Phytophthora root and stem rot, and seedling diseases caused by, Fusarium, Phomopsis spp., Pythium, and Rhizoctonia solani.