Delaware Agronomy Blog

University of Delaware Cooperative Extension

2018-2020 Wheat Seeding Rates

Over the past three years we have been planting winter wheat seeding rates ranging from 900,000 up to 2.2 million seeds per acre. Averaged over the last three seasons (2018-2020), yields ranged from 85-93 bu/acre, with some differences between seeding rates (Figure 1).

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2019-2020 Corn Growing Degree Days

The standard method used to follow and predict corn growth stages is using growing degree days (GDD). This is a calculation that uses average daily temperatures to measure accumulated heat over the growing season. Most of the GDD values we use are from the Mid-West, so we have followed a few research fields the past two years to compare how DE lines up. We have also included days from planting and light accumulation (pulled from DEOS) to compare other measurement methods (Table 1 – flip phone sideways for best presentation).

Table 1: Following Corn Vegetative Growth Stages (2019-2020)
Emerge V3 V6 V9 V12 VT
Days from Planting 5-13 12-31 22-48 35-63 44-76 53-82
Growing Degree Days 84-150 219-310  492-603 787-950 1001-1337 1231-1322
Total Light 125-302 271-609 530-996 828-1343 1055-1664 1265-1508

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Considering Fall Salt Remediation

Salts are a natural component of soils, including our soluble plant nutrients (Ca, NO3, ect). Excessive levels of any salt can be detrimental to both plant health and soil quality. On the Delmarva Peninsula, excessive salts can come through several sources, which include fertilizers, irrigation water, and salt water intrusion.

Fertilizer burn due to sidedress N applications.

Issues with fertilizers are related to seed germination and growth, where in-furrow recommendations of starter N+K fertilizers are limited to 10 lb/acre total due to salt effects. During sidedress applications, fertilizer burn (Figure 1) can damage leaf tissue, particularly UAN greater than 50lb/acre. As long as corn plants are younger, minimal tissue damage doesn’t affect yield. Considering the above recommendations, salt damage due to fertilizers should be easy to manage. Continue reading

2020 Virtual Mid Atlantic Crop School Registration

Crop School registration is now live, see our main page for more details and links:https://sites.udel.edu/agronomy/cropschool/

 

 

Checking for Corn Maturity

 Jarrod O. Miller, Extension Agronomist, jarrod@udel.eduCory Whaley, Sussex Co. Extension Ag Agentwhaley@udel.edu;

Figure 1: Dough stage (R4) with some denting present.

At this point in the season many fields may have started to show signs of dent, but this is a slow transition that sits between two reproductive stages. At the dough stage (R4), the milky fluid is drying down, giving the kernel a soft, dough like consistency (Figure 1). As some of these kernels continue to dry and starch forms at the crown, a dent will form on the outer edge of the kernel. However, to be at the actual dent stage (R5), almost all of the kernels should have the dent feature (Figure 2). Continue reading

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