Burndown herbicides in Crambe abyssinica crops: seed yield and quality

ABSTRACT The application of burndown herbicides to crambe crops is important for production of quality seeds. The objective of this work was to evaluate the effect of burndown herbicides applied at pre-harvest, using different spray volumes, on seed yield and quality of crambe plants (Crambe abyssinica cv. FMS Brilhante). A randomized block experimental design was used, with four replications, in a 2 × 5 factorial arrangement consisted of two burndown herbicides [glyphosate (Roundup Original 360 g L-1) and diquat (Reglone 200 g L-1)] and five spray volumes (0.0, 0.5, 1.0, 1.5, and 2.0 L ha-1). The burndown herbicides were applied at 74 days after sowing, when the plants presented 80% brown seeds, based on visual evaluation of the seed maturation stage. After harvest, the seeds were processed and evaluated for water content, one-thousand seed weight, seed yield, oil contents, germination, and vigor (first germination counting, emergence speed index, accelerated aging, and electrical conductivity). The pre-harvest desiccation of crambe with the herbicide diquat, using spray volumes between 1.3 and 1.5 L ha-1, resulted in seeds with better physiological quality. The seed vigor was low when using desiccation of plants with glyphosate. The crop yield was not affected by the herbicides nor by the different spray volumes.

摘要
灭生性除草剂（burndown herbicides）在荠蓝作物上的施用对优质种子生产至关重要。本研究旨在评估收获前施用不同喷施体积的灭生性除草剂对埃塞俄比亚荠蓝（Crambe abyssinica cv. FMS Brilhante）种子产量与品质的影响。试验采用随机区组试验设计，设置4次重复，采用2×5因子排列：2种灭生性除草剂分别为草甘膦（Roundup Original 360 g L⁻¹）与敌草快（Reglone 200 g L⁻¹），另设5个喷施体积梯度（0.0、0.5、1.0、1.5及2.0 L ha⁻¹）。于播种后74天，即通过目测评估种子成熟阶段、植株种子褐变率达80%时喷施上述除草剂。收获后对种子进行清选处理，依次测定其含水量、千粒重、种子产量、含油率、发芽率及活力指标（首次发芽计数、出苗速率指数、加速老化试验及电导率测定）。
结果表明：采用敌草快、喷施剂量为1.3~1.5 L ha⁻¹对荠蓝进行收获前干燥处理，可获得生理品质更优的种子；使用草甘膦进行植株干燥处理时，种子活力较低；除草剂类型及不同喷施体积均未对作物产量产生显著影响。