Emmalea Ernest, Extension Fruit & Vegetable Specialist; emmalea@udel.edu
At this point in the season stand and vigor issues are readily apparent in early sweet corn plantings. Good stand establishment is important for fresh market sweet corn since generally each plant yields only one marketable ear. Plantings with poor stands will have reduced yields. Low plant vigor can also reduce marketable yield or delay harvest. This year I am trialing 18 white supersweet sweet corn varieties at two planting dates: April 17 and May 23. Last week we collected data on emergence and plant height in the April 17th trial and there are notable differences between varieties (Figure 1, Table 1) in emergence and vigor (plant height). These differences are likely the result of differences in variety sensitivity to cold soils but could also be impacted by seed quality.
Figure 1. Emergence and vigor was good in Endurance (top) compared to Summer Sweet Multisweet 2001MR (bottom)
Table 1. Percent emergence and plant height for white supersweet corn varieties planted on April 17, 2024.
The best emergence and vigor were observed in Endurance, Nicole and Leadoff (Figure 2.) Other varieties with good emergence and vigor were Seabright, Xtra-Tender 3572, Platinum, Guardian, 7401 IMP, Xtra-Tender 378A and White Lightening. The varieties SSM 2001 MR had the lowest emergence and plants were small. XTH 3380, Silver Thunder and Glacial also had low emergence and vigor. Silver Thunder had the smallest plants out of all the varieties. Freedom had 70% emergence, but plants were small. As I analyze the data from this year’s trials, I will be looking for correlation between early vigor and yield as well as the expected correlation between stand and yield.
Figure 2. Percent emergence and plant height 29 days after planting in 18 white supersweet corn varieties planted on April 17, 2024.