|ROYO-ESNAL, ARTIZ - Universitat De Lleida
|NECAJEVA, JEVGENIJA - Latvijas Universitate
|TORRA, JOEL - Universitat De Lleida
|RECASENS, JORDI - Universitat De Lleida
|Gesch, Russell - Russ
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2014
Publication Date: 1/28/2015
Citation: Royo-Esnal, A., Necajeva, J., Torra, J., Recasens, J., Gesch, R.W. 2015. Emergence of field pennycress (Thlaspi arvense L.): Comparison of two accessions and modelling. Industrial Crops and Products. 66:161-169.
Interpretive Summary: Some weed species such as field pennycress (Thlaspi arvense) are becoming rare in certain parts of the world because of the effectiveness of agricultural weed control practices. Although weeds are typically considered bad for crop production, they can also add biodiversity to rural landscapes and provide habitat for wildlife and pollinating insects such as honey bees. Pennycress, which belongs to the mustard family, has recently been shown to have agronomic value as feedstock for biofuels and bioproducts. Therefore, growing pennycress as an agricultural crop could serve the purpose of preserving the species for conservation as well as harvesting its seeds for profit. However, pennycress has not been domesticated and understanding its pattern of seedling emergence following planting will greatly help in managing it for conservation and agronomic purposes. A collaborative study was conducted with scientists in Spain and Latvia to investigate emergence patterns of two different populations of pennycress: one originating from Spain and the other from the USA. Both populations were grown in the field for two years in Almenar, Spain and Morris, MN, USA, and one year in Riga, Latvia. The data collected were used to develop two mathematical models for predicting pennycress emergence. Both models included soil temperature and moisture to help predict emergence, but one of the models also included photo-period as a factor, which was found to increase the accuracy of the model to predict emergence across the different environments in Spain, Latvia, and the USA. Emergence of the USA pennycress was greater than the Spanish population at all locations and patterns of emergence slightly differed between the Spain and USA environments. Nevertheless, both of the models developed did a good job of predicting emergence, while the one that included photo-period as a factor, improved the prediction accuracy. Results indicate that certain populations such as that from the U.S. are likely to be better candidates for being used as a crop. Results provide a better basic understanding of environmental factors affecting the emergence of pennycress and will help agronomists, agricultural consultants, and university extension personnel establish management guidelines, such as optimal planting time and environmental conditions, for growing pennycress as a crop.
Technical Abstract: Many weed species are becoming rare due to intense agricultural management, which leads to a decrease of biodiversity in agroecosystems. Cultivating some of these species for their oilseed content may help preserve them while profiting agronomically. Thlaspi arvense is one of these species with potential as a crop. Knowledge of emergence patterns using modeling can help to make decisions for its management, whether for conservation or production purposes. The emergence of two accessions of T. arvense, one from Spain and the other from USA, sown in Spain (Almenar) and USA (Morris), over two seasons (2011-12 and 2012-13) and in Riga (Latvia) over one season (2012), was followed to compare patterns and extent, as well as to develop emergence prediction models based on hydrothermal time (HTT) and photohydrothermal time (PhHTT). Emergence of the USA accession was significantly higher than that of the Spanish accession. Both accessions presented two emergence peaks (autumn-winter and spring) in both localities, but while these peaks could be considered as two different flushes in Spain, they appeared to be a single flush disrupted by low winter temperatures in USA. On the other hand, HTT based model was applicable for both accessions with less precision, while PhHTT based one seemed more accurate in most cases but failed in certain circumstances for the USA accession. Precipitation is the determining factor affecting the establishment of T. arvense populations. The differences in emergence patterns among accessions suggest that some accessions might be more amenable to being used as crop. The two models developed in this work predicted quite accurately the emergence of T. arvense for both accessions. Finally, the inclusion of photoperiod in the hydrothermal time equation, creating a new unit that we have called photohydrothermal time, offers a possibility to obtain more accurate models.