Effect of Polymer Seed Coating with Micronutrients on Soybeans in Southeastern Coastal Plains

Abstract

Polymer seed coating with micronutrients may affect soybean (Glycine max (L.) Merr) growth and yields under dryland conditions. The objective of this study was to determine the effect of two seed application rates (265 and 395 mL 100 kg seeds^-1) of polymer based mixture of Copper (Cu), Manganese (Mn) and Zinc (Zn) micronutrients on dryland soybeans near Blackville, SC from 2011 to 2012. Soybeans were evaluated for plant Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), plant height, seed weight and grain yields. Compared to untreated control, polymer seed coating significantly increased grain yields by 8.1 and 14.0% with seed applications at 265 and 395 mL 100 kg seeds^-1, respectively. Plant NDVI improved by 10.5% with application of polymer seed coating treatment at 395 mL 100 kg seeds^-1. Seed coating at 265 and 395 mL 100 kg seeds^-1 significantly increased plant NDVI by 10.2 and 10.8% at 8 weeks after soybean planting and 4.6 and 4.2% at 12 weeks after planting. Based on significant linear relationships, grain yields increased by 179.2 kg ha^-1 with increasing plant NDVI by 0.1 unit at 6 weeks after planting soybeans and 99.4 kg ha^-1 with increasing weight by 1 g of 100 seeds. Treatment application did not affect plant NDVI at 4 through 6 and 9 weeks after planting, plant LAI at 8 and 12 weeks after planting and plant height. These results indicate that polymer seed coating may help to improve some growth parameters and grain yields of soybean under dryland conditions in Southeastern Coastal Plains.