Evaluating Diverse Corn Genotypes for Biomass Production in Iowa.

Evaluating Diverse Corn Genotypes for Biomass Production in Iowa

ABSTRACT

Previous research has indicated tropical corn might have a significant potential to achieve high biomass yields under day lengths of temperate regions. The potential for tropical genotypes has been evaluated mainly for grain production in Central Iowa. Nevertheless, tropical germplasm for temperate environments are not attractive for grain yields, and demonstrate features detrimental to corn grain yield like a high grain moisture at harvest, late flowering and tall plants. Tropical corn, however, has been adapted as a source of potential germplasm for Iowa conditions by selecting for earlier flowering, both adapted and unadapted sources of tropical corn show promising results for biomass potential, i.e., taller and more vigorous plants with thick stems and long leaves.

Until now, commercial hybrids and tropical corn comparisons for biomass production have been explored very little especially in Iowa. Field trials were established at the Sorensen Research Farm in Boone County, IA during the 2014 and 2015.  Six genotypes (four hybrids of 104 RM, 110 RM, 114 RM, 120 RM, and two tropical corn of 130 RM) were planted in mid May (20 May 2014 and 13 May 2015) to evaluate biomass production, crop growth, and light interception response. This study also identified the effect of management practices in terms of plant density, row spacing, nitrogen recommendation, and relative maturity of genotypes on overall crop growth. Tropical genotypes with longer growth cycles and a higher sensitivity to photoperiod compared to the hybrids resulted in delayed flowering time and greater biomass yields.  Hybrids yielded more grain yields and grain development, while tropical corn had greater biomass yields. These results indicate a high potential for tropical corn for biomass production. The agronomic package recommended for biomass production including plant arrangement and management practices, was different than the package for grain production.