Jim Specht - Emeritus Professor of Agronomy

Frost damaged sorghum — If sorghum is at hard dough stage when temperatures dip to 28°F for a period of two hours, it may result in a yield reduction of around 20%.

Premature Frost Damage to Crops

October 14, 2022

UNL experts weigh in on the potential impacts for replant crops that experienced freezing temperatures Oct. 8 or may be at risk for a freeze this weekend.

Figure 1. Soybean pods collected from stage R7 plants (one mature pod per plant) that were opened to determine if the pod wall interior membrane was still clinging tightly to the seeds (leftmost pod), or if it was beginning to detach from the seeds (second pod), or if the membrane was now permanently attached to the pod wall (third pod). After attaining physiological maturity, seeds undergo a dry-down period from about 60% moisture to about 13% moisture. Note that the Rx.x numbers used here are pod-based stages, not plant-based stages.

Understanding Ending Reproductive Stages in Soybean

August 27, 2021

The timing of the ending R stages in soybean is governed by planting date (PD) and varietal maturity group (MG), though the date of R7 can be hastened if water stress and high temperatures prevail in August — something we are seeing in portions of Nebraska this year.

What Have We Learned about Soybean Seed Constituents in Irrigated and Dryland Producer Fields in Nebraska?

June 14, 2021

With a continuous decline in seed protein concentration in U.S. soybeans, UNL researchers examined how irrigation practices in Nebraska may contribute to this issue for soybean growers.

Q/A: Questions about Soybean Emergence and Stands

May 27, 2021

There are many factors for producers with soybean emergence and stand issues to consider; this article reviews potential causes, identification techniques and management options.

Tracking Soil and Air Temperatures — Soybean Planting Considerations

April 14, 2021

Results of ongoing Nebraska Extension field demonstrations to determine critical soil temperatures and trends for soybean germination and emergence, plus early soybean planting considerations.

Soybean imbibitional time research — Jim loading seed trays for the indoor soybean study (left) and trays in the 36°F cooler (right). (Photos by Jenny Rees)

Demonstrating Critical Imbibitional Time for Soybean

April 14, 2021

This Nebraska Extension indoor study offers a comprehensive analysis of the timing and duration of the critical imbibition water uptake phase for soybean, to assist growers in their decisions on planting dates this spring.

emerging corn showing varying degrees of frost damage

Evaluating Freeze and Chilling Injury in Corn and Soybeans

May 13, 2020

The weather took a turn to the cold side over the last week. Across Nebraska, lows at or below 32°F were recorded. Clear conditions coupled with these temperatures favor frost formation especially in low lying areas. So, what does this mean for our crops?

Corn and Soybean Planting Considerations for 2020

April 22, 2020

Everything we do at planting sets the stage for the rest of the year. With tight economics, it’s important to make wise decisions with the factors we can control during planting season.