Classification of temperature response in germination of Brassicas

Authors: Russo, Vincent; Bruton, Benny; SAMS, CARL - UNIV. TENNESSEE

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2009
Publication Date: 11/23/2009
Citation: Russo, V.M., Bruton, B.D., Sams, C.E. 2010. Classification of temperature response in germination of Brassicas. Industrial Crops and Products. 31:48-51.

Interpretive Summary: Seed of varieties and cultivars of the Brassicas are used as sources of oil. These are, for the most part, considered cool-season crops planted in the fall for harvest the following year. It may be possible that these crops could be grown in regions where they have not typically been grown if other planting windows are used. Seed of varieties of canola, mustard and camelina were kept moist in growth chambers and incubated 4, 10, 16, 21, 27 or 32C for up to 12 days. Some varieties had the most germination by 2 days and others by 4 days. Some germinated equally well across all tempertures and others germinated better at specific temperatures. Variability in Brassica seed germination in response to temperature indicates that there may be the opportunity for flexibility in the planting dates over which these crops can be sown.

Technical Abstract: Since soil temperature affects germination and emergence of canola (Brassica napus L.), mustard [B. juncea (L.) Czerniak. and Sinapsis alba L.], and camelina [Camelina sativa (L.) Crantz.], planting dates have to be adjusted to prevent crop failures. These crops can be used as biofuel feedstocks, and some mustards can also be used as a soil biofumigant. Knowledge of germination temperature optima/range for canola and mustard is critical for inclusion of these crops into existing crop rotations. The canola varieties 'Clearwater' (UI-C-1), 'DKW13-86' (Roundup[trademark] ready), and 'Gem' (UI-G-1), the mustards 'Caliente 61,' 'Florida Broadleaf,' 'Idagold,' 'Kodiak Brown,' and 'Pacific Gold,' and the camelina line 'NEB C-1' were germinated in the dark in Petri-dishes at 4, 10, 16, 21, 27 or 32C for 12 days. The line NEB C-1 and variety Gem achieved maximum germination after 2 days at 16C; varieties 'DKW13-86' and Clearwater achieved maximum germination after 2 days at 21C. The line NEB C-1 had complete germination from 4 to 27C, but declined dramatically at 32C; Clearwater had an average total germination percentage of about 90% over all temperatures, but germination of DKW13-86 and 'Gem' increased as temperature increased over the range tested. The varieties Caliente 61, Idagold and Kodiak Brown achieved maximum germination at 16C after 2 days compared with Florida Broadleaf and Pacific Gold, which had maximum germination after 2 days at 21C. Germination percentages ranged from slightly less than 90% to 100% for the mustard varieties Caliente 61 and Idagold at temperatures from 10 to 32C. Germination of Florida Broadleaf increased from about 45% at 4C to 90 to 100% from 16 to 32C. Kodiak Brown and Pacific Gold exhibited optimum germination between 16 and 27C. Variability in Brassica seed germination in response to temperature indicates that there may be the opportunity for flexibility in the planting dates over which these crops can be sown.