Jim Heitholt, Ph.D.

Administrative
Heitholt ensures that researchers from across the state with projects at the Powell REC have the resources and help needed to conduct quality field research. He encourages researchers to provide deliverables (bulletins with results) to Bighorn Basin stakeholders. Heitholt meets routinely with stakeholders to revisit short-term and long-term producer goals.

Research
Heitholt’s research is primarily crop yield physiology but with major emphasis on phenotyping (for identifying important genotype-by-management interactions). He also contributes to the region’s crop improvement effort by generating novel dry bean germplasm through conventional crossing. The major theme of Heitholt’s research is to reduce grower input costs and improve profitability while at the same time foster the use of more environmentally‑friendly agronomic management practices.
Heitholt, in collaboration with Vivek Sharma, has identified drought-tolerant dry bean cultivars and experimental lines that growers might use in a deficit irrigation management. Dry bean studies were originally launched in 2015 and 2016 at the UW-REC in Lingle (WY) and were ultimately expanded to Powell REC in 2017 and 2018. The most important finding within these studies is that grain yield of the entries was negatively correlated to canopy temperature (CT) readings obtained during flowering and throughout grain-fill. The yield vs. CT correlations were consistent regardless of whether the data were collected under full irrigation or under deficit irrigation. In 2019, Heitholt also observed this correlation within a small set of sister lines which suggests that CT needs to be considered further for use in breeding and screening programs.
Additionally, Heitholt continues to phenotype dry bean cultivars and his own progeny lines for tolerance to low soil N and low soil P. Despite being an N2-fixing legume, dry bean is a poor N2-fixer and extension literature across the US dry bean belt recommends that fertilizer N be added if soil NO3-N is below 10 ppm. Heitholt and his graduate student, Ali Alhasan, have conducted five years of greenhouse and field research comparing dozens of dry bean cultivars for their response to varying N fertilizer rates. Results have indicated that yield response to fertilizer N (average across cultivars) is minimal and that N fertilizer recommendations need revisted. Other researchers throughout the US dry bean belt have also found inconclusive grain yield results to soil-applied N. Positive effects of N on other traits such as leaf chlorophyll and vegetative growth are consistently observed, however. Genotype‑by-N interactions are rather inconsistent although it appears that certain cultivars are able to tolerate low soil N better than others. Researchers in other parts of the world continue to identify lines with greater N2-fixing capacity and ultimately these lines will be used as parents in US dry bean breeding programs in hopes that producers can reduce N application rates.
Heitholt recently launched a project in hopes of reducing N rates in sugar beet, another major crop grown in the Bighorn Basin. First year results suggest that the typical 200 pounds N per acre rate may not be required. Heitholt is testing soil amendments in combination with different N rates to see if adjustments to the rhizosphere can improve N uptake and reduce N application rates.
Heitholt has generated numerous dry bean progeny lines that are being evaluated for their performance under deficit irrigation, low soil N, or low soil P. So far, none of the experimental lines have proven superior to the top performing commercial line(s) but Heitholt has found multiple lines superior to the parental lines. Earliness and upright stature are primary breeding goals for Heitholt’s breeding program and although some of his material looks promising, he only plans for a germplasm release at this time as opposed to a cultivar release.

Teaching
Heitholt teaches a graduate level crop physiology course and an undergraduate course in Crop Yield Physiology. Heitholt also assists with the teaching of Field Crop Production. All of Heitholt's courses are taught online with prerecorded lessons made available to the students and with online discussions held throughout the semester.

Outreach
Heitholt does not have formal extension responsibilities but supports extension and outreach for regional educators and statewide specialists as needed or requested. Heitholt’s primary role in outreach is to mentor undergraduate interns that seek to learn more about laboratory, greenhouse, and field plot research. Students from nearby Northwest College are routinely hired to work with the faculty and staff at PREC to learn about crop management, measurement of ecophysiological traits, and growth staging of crop canopies.

Updated March, 2020