Occurrence of arthropod pest species associated with B. carinata and impact of defoliation on yield and oil quality

Authors: BALDWIN, JESSICA - University Of Florida; PAULA-MORAES, SILVANA - University Of Florida; MULVANEY, MICHAEL - University Of Florida; Meagher, Robert - Rob

Submitted to: Bio Energy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/18/2020
Publication Date: 12/30/2020
Citation: Baldwin, J.M., Paula-Moraes, S.V., Mulvaney, M.J., Meagher Jr, R.L. 2020. Occurrence of arthropod pest species associated with B. carinata and impact of defoliation on yield and oil quality. GCB Bioenergy. 13(4):570-581. https://doi.org/10.1111/gcbb.12801.
DOI: https://doi.org/10.1111/gcbb.12801

Interpretive Summary: The Abyssinian cabbage (mustard) plant, Brassica carinata, can be grown as a winter crop in the southeast United States, especially north Florida. This plant has the potential to become an economically important aviation biofuel source because the plant oil can be used as a component of jet fuel. Unfortunately, little is known about the identity of insect pests that can defoliate these plants and impact yield and quality of the oil. A scientist from USDA-ARS, Center for Medical, Agricultural and Medical Entomology, Gainesville, Florida, in collaboration with scientists from the University of Florida documented the numbers and species of insect pests that were found in the upper, middle, and lower plant parts of 16 varieties of Abyssinian cabbage grown in north Florida. The study demonstrated that several insect species, that infest other common mustards, can infest and damage Abyssinian cabbage plants during the vegetative and flowering stages. Additionally, they found that the distribution of the insects on the plants was not localized to any part but uneven. This work provides the foundation for determining the nature of the insect pests and their densities to establish the appropriate pest control measures so that Abyssinian cabbage can be grown as a profitable biofuel crop.

Technical Abstract: Brassica carinata has the potential to become an economically important biofuel winter crop in the Southeast United States. However, an IPM program is needed to provide pest management recommendations for B. carinata in the region. This study documented pest occurrence, pest position within the canopy, and the impact of defoliation on B. carinata yield and oil quality. The study was performed in Jay, FL during the 2017/2018 and 2018/2019 winter/spring crop seasons. Pest species occurring in B. carinata were documented by plant inspection within 16 genotypes of B. carinata. In each plot, one plant was divided into three canopy zones (upper, medium and lower canopy) and inspected for the presence of pests. The defoliation impact on B. carinata was evaluated by artificial defoliation. Five levels of defoliation (2017/2018 crop season: 0%, 5%, 25%, 50%, and 100%; 2018/2019 crop season: 0%, 50%, 75%, 90%, and 100%) were artificially applied during three different plant stages on the commercial cultivar “Avanza64.” The plants were hand harvested and the average number of pods/plants, seeds/pod, thousand seed weight, and yield were determined and correlated with defoliation levels. Results indicated that B. carinata is associated with several species of insect pests in the Southeast U.S. The insect distribution within the plant canopy was not uniform. The number of pods/plants, number of seeds/pods, oil concentration, erucic acid concentration and yield were negatively impacted by defoliation during the vegetative and flowering stages.