Semester of Graduation

Summer 2021

Degree

Master of Science (MS)

Department

SPESS

Document Type

Thesis

Abstract

Plant spacing variability and non-uniform emergence in corn (Zea mays L.) is not uncommon in Louisiana corn fields. Variation in planting depth, non-uniform surface crop residue distribution in no-tillage systems, microsite variation in the seed bed condition, and seed vigor are major factors responsible for non-uniform emergence. Also, planters with low precision in seed placement and careless planting operations can cause non-uniform spacing. Two studies were conducted to quantify the effects of plant spacing variability and non-uniform emergence on grain yield in corn. Six plant spacing treatments at 47,770 plants ha-1 were evaluated. Uniform spacing, seed skip, double seeded, seed offset by ¼ , seed offset by ½, and seed offset by ¾. Although seed skips produced an increase of 12% g ear-1, the absence of a plant within the subplot collectively resulted in a 25% yield reduction compared to uniform spacing. A 15% yield decrease was observed in double seeded treatments compared to uniform spacing. There were no significant differences in yield for uniform spacing, seed offset by ¼, ½, or ¾ treatments, respectively. A second study was conducted to evaluate the impact of zero, two, and four leaf delays in corn emergence on yield. Two and four-leaf delay treatments reduced grain weights by 55% and 92%, respectively, compared to the zero-leaf delay.


Committee Chair

Stephenson IV, Daniel O.

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