Chao Wun S, Anderson James V, Li Xuehui, Gesch Russ W, Berti Marisol T, Horvath David P
USDA-ARS, Edward T. Schafer Agricultural Research Center, Fargo, ND 58102, USA.
Plant Sciences Department, North Dakota State University, Fargo, ND 58108, USA.
Plants (Basel). 2023 Mar 15;12(6):1329. doi: 10.3390/plants12061329.
Winter oilseed cash cover crops are gaining popularity in integrated weed management programs for suppressing weeds. A study was conducted at two field sites (Fargo, North Dakota, and Morris, Minnesota) to determine the freezing tolerance and weed-suppressing traits of winter canola/rapeseed ( L.) and winter camelina [ (L.) Crantz] in the Upper Midwestern USA. The top 10 freezing tolerant accessions from a phenotyped population of winter canola/rapeseed were bulked and planted at both locations along with winter camelina (cv. Joelle) as a check. To phenotype our entire winter population (621 accessions) for freezing tolerance, seeds were also bulked and planted at both locations. All and camelina were no-till seeded at Fargo and Morris at two planting dates, late August (PD1) and mid-September (PD2) 2019. Data for winter survival of oilseed crops (plants m) and their corresponding weed suppression (plants m and dry matter m) were collected on two sampling dates (SD) in May and June 2020. Crop and SD were significant ( < 0.05) for crop plant density at both locations, and PD in Fargo and crop x PD interaction in Morris were significant for weed dry matter. At Morris and Fargo, PD1 produced greater winter survival (28% and 5%, respectively) and PD2 produced higher camelina survival (79% and 72%, respectively). Based on coefficient of determination (), ~50% of weed density was explained by camelina density, whereas ≤20% was explained by density at both locations. Camelina from PD2 suppressed weed dry matter by >90% of fallow at both locations, whereas weed dry matter in was not significantly different from fallow at either PD. Genotyping of overwintering canola/rapeseed under field conditions identified nine accessions that survived at both locations, which also had excellent freezing tolerance under controlled conditions. These accessions are good candidates for improving freezing tolerance in commercial canola cultivars.
冬季油料现金覆盖作物在综合杂草管理计划中因能抑制杂草而越来越受欢迎。在美国中西部上游地区的两个田间地点（北达科他州法戈和明尼苏达州莫里斯）开展了一项研究，以确定冬油菜/油菜（ ）和冬亚麻荠[ (L.) 克兰茨]的抗冻性及杂草抑制特性。从一个经过表型分析的冬油菜/油菜群体中选取了10个抗冻性最强的种质进行混播，并与冬亚麻荠（品种乔乐尔）一起在这两个地点种植作为对照。为了对我们整个冬季群体（621个种质）进行抗冻性表型分析，种子也进行了混播并在这两个地点种植。所有油菜和亚麻荠于2019年8月下旬（播种日期1）和9月中旬（播种日期2）在法戈和莫里斯两个地点免耕播种。在2020年5月和6月的两个采样日期收集了油料作物冬季存活情况（每平方米植株数）及其相应的杂草抑制情况（每平方米植株数和每平方米干物质量）的数据。作物和采样日期对两个地点的作物种植密度均有显著影响（ < 0.05），法戈的播种日期以及莫里斯的作物×播种日期交互作用对杂草干物质量有显著影响。在莫里斯和法戈，播种日期1的冬油菜存活率更高（分别为28%和5%），播种日期2的冬亚麻荠存活率更高（分别为79%和72%）。基于决定系数（），约50%的杂草密度可由亚麻荠密度解释，而在两个地点由油菜密度解释的比例均≤20%。来自播种日期2的亚麻荠在两个地点均能抑制超过90%的休耕地杂草干物质量，而在两个播种日期下，油菜地的杂草干物质量与休耕地均无显著差异。在田间条件下对越冬油菜/油菜进行基因分型，确定了9个在两个地点均存活的种质，这些种质在受控条件下也具有优异的抗冻性。这些种质是提高商业化油菜品种抗冻性的良好候选材料。
