Compositions and methods for improving crop yields through trait stacking

A transgenic corn plant or a plant part thereof comprising (i) a first recombinant expression cassette comprising a first heterologous plant-expressible promoter operably linked to a transcribable DNA sequence encoding a non-coding RNA for suppression of one or more gibberellic acid 20 (GA20) oxidase genes, and ii) a second recombinant expression cassette comprising a DNA sequence encoding a MADS-box polypeptide having at least 95% amino acid sequence identity to the amino acid sequence as set forth in SEQ ID NO:

• 168;
• wherein the non-coding RNA comprises a targeting sequence that is (a) at least 95% complementary to at least 19 consecutive nucleotides of a first mRNA molecule encoding a first endogenous GA20 oxidase protein that has at least 95% amino acid sequence identity to the amino acid sequence as set forth in SEQ ID NO:
• 9, and (b) at least 95% complementary to at least 19 consecutive nucleotides of a second mRNA molecule encoding a second endogenous GA20 oxidase protein that has at least 95% amino acid sequence identity to the amino acid sequence as set forth in SEQ ID NO:
• 15;
• and wherein expression of said non-coding RNA and said MADS-box polypeptide in said transgenic corn plant results in a semi-dwarf phenotype, and an increase in one or more improved ear trait selected from the group consisting of ear diameter, single kernel weight, ear fresh weight, ear area, ear volume, ear length, kernels per ear, yield, grain yield estimate, broad acreage yield, ear dry weight, and ear tip void, as compared to a control wild-type corn plant grown under comparable conditions.