Location: Soil Management ResearchTitle: Germination and emergence of Neslia paniculata (L.) Desv
|ROYO-ESNAL, ARTIZ - Universitat De Lleida|
|Gesch, Russell - Russ|
|NECAJEVA, JEVGENIJA - University Of Latvia|
|EDO-TENA, EVA - Universitat De Lleida|
|RECASENS, JORDI - Universitat De Lleida|
|TORRA, JOEL - Universitat De Lleida|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2018
Publication Date: 1/1/2019
Citation: Royo-Esnal, A., Gesch, R.W., Necajeva, J., Forcella, F., Edo-Tena, E., Recasens, J., Torra, J. 2019. Germination and emergence of Neslia paniculata (L.) Desv. Industrial Crops and Products. 129:455-462. https://doi.org/10.1016/j.indcrop.2018.12.030.
Interpretive Summary: Seed size or structure can affect germination and the emergence of seedlings. Neslia paniculata (aka: ball mustard) is a common weed belonging to the mustard family that is primarily found in cool, temperate climates throughout the world. Improved knowledge of seed germination and emergence of ball mustard will help to manage it as a weed or as a potential new oilseed crop. Seed germination tests were conducted in the laboratory under constant temperatures from 5 to 23°C, and field experiments were performed in Spain, Latvia, and Morris, Minnesota USA to measure emergence under different environmental conditions. The data collected was then used to build mathematical models of ball mustard germination and emergence. Results showed that ball mustard is a winter species well adapted to low temperatures. In fact, temperatures above 11°C (52°F) inhibited seed germination. We found that the base temperature for ball mustard seed germination and emergence (i.e., the lowest temperature at which seeds can still germinate and emerge) was below 0°C (32°F). It was discovered that ball mustard seeds have both a physiological and physical dormancy that can delay or even prevent germination. The physical dormancy is caused by a thick and hard coat surrounding its seed. It was demonstrated that a hydrothermal time model (i.e., a model that considers both soil moisture and temperature) best predicted ball mustard seedling emergence. Unlike other mustard species that have been studied, ball mustard emergence did not appear to be affected by light exposure. Also, its relatively large seed size allows seedlings to emerge from deeper soil depths and explains the need for considering soil moisture at 8-10 cm, as compared to 4-8 cm typical of other mustard species, as a critical variable for predicting seedling emergence. This study provides new knowledge that will benefit researchers, agricultural consultants, and extension educators who are concerned with mustard species. The knowledge allows development of improved guidelines for management of this species as a weed or a potentially new oilseed crop.
Technical Abstract: Seed size or structure can affect germination and the emergence of seedlings. Neslia paniculata (Brassicaceae) produces relatively large one-seeded fruits covered by a hard fruit coat. Germination was tested at constant temperatures from 5 to 23ºC and followed daily. Tests also were performed with and without intact fruit coats. Additionally, seeds were sown in field soils at three sites (Almenar, Spain; Morris, MN, USA; and Riga, Latvia) with emergence followed periodically. Both germination and emergence were modelled with Boltzmann and Weibull models. Results show that N. paniculata is a winter species adapted to low temperatures. Temperatures above 11°C inhibited germination. Base temperatures for both germination and emergence were below 0°C. Seeds have both physiological and physical dormancy, the latter due to the thick fruit coat. Soil hydrothermal time best predicted seedling emergence. In contrast to other Brassicaceae, light did not correlate with seedling emergence. The relatively large size of the seeds of N. paniculata allows seedlings to emerge from deeper soil depths and explains the need for considering soil moisture at 8-10 cm, as compared to 4-8 cm typical of other Brassicaceae, as a critical variable for predicting seedling emergence.