No abstract

No abstract

A critical step in production of winter rapeseed (Brassica napus L.) in humid environments is seed harvest. This 3‐yr study (1986 to 1989) evaluated the effect of harvesting method, harvester type, and seed color stage on seed yield of three rapeseed cultivars (‘Westar’, ‘Cascade’, and ‘Bridger’) near Tifton, GA. No consistent trends were exhibited by swathing or direct combining rapeseed. Seed yield was influenced by weather conditions and crop stage rather than harvesting methods. Both harvesting methods seem potentially acceptable for rapeseed production in the Southeastern USA; however, the added input requirements for swathing may reduce the economic potential for this practice. A draper table‐type combine significantly reduced seed yield losses when compared with an auger‐type combine. Auger‐type combines may need modification to reduce potential seed losses. Mechanical losses reduced total seed yields from 21 to 66%. The best machine‐harvested rapeseed yields were obtained in 1988–1989 with a draper table‐type harvester, either directly combining at 70 to 90% of dark seed (average yield for all cultivars of 1427 lb/acre) or swathing at 50 to 70% of dark seed (average yield of 1294 lb/acre).

No abstract

Oilseed rape (Brassica nupus L.), including industrial (rapeseed) and canola quality cultivars, offers potential for doublecropping in the southeastern USA. Early attempts at commercialization of this crop in the Southeast have frequently encountered difficulties in establishing stands. This 3‐yr project (1986–1989) was undertaken to evaluate the effects of seeding depth and planter configuration (i.e., packing wheel pressure) on emergence of oilseed rape. The two field sites used for this study contained Lakeland sand (thermic, coated Typic Quartzipsamment) and Tifton loamy sand (fine, loamy, siliceous Plinthic Paleudult) soil types, respectively. Treatment factors were planter configuration, seeding depth, and cultivar. The experimental design was a randomized complete block with four replications. Planter configurations consisted of a Tye drill with both high and low pressure settings on the packing wheels and an Amazone drill with no packing wheel pressure (second season only). Seeding depths ranged from 0.25 to 2 in. Cultivars were ‘Cascade’ and ‘Westar’ for all three seasons and ‘Bridger’ during the last two seasons. Results showed better crop establishment when planted shallow (0.25–0.5 in.) than deep (1.5–2 in.). High packing wheel pressure at planting had a positive effect on stand when the crop was sown on sandy soil with little potential for surface crusting. For example, on the cultivar Cascade, the increased packing wheel pressure increased the stand density by 15% over the low packing wheel pressure in the second season. For Westar in the same season and at the 1.5 in. depth, the stand density increased nearly 40% when packing wheel pressure increased. However, on loamy sand soils, which have a greater potential for crusting, better emergence occurred when low packing wheel pressure was applied. Research Question Oilseed rape, inclusive of both canola and rapeseed quality cultivars, has emerged as a potential alternative winter crop in the southeastern USA. Production questions remain, including the optimum seeding depth and planter configuration (press wheel pressure), for crop establishment. The primary objective of this research was to evaluate several seeding depth and planter configuration alternative effects on emergence of several cultivars with potential to be grown in the southeastern USA. Literature Summary Previous studies have investigated effects of harvest technique on oilseed rape yield, cultivar responses, and the impacts of planting date on crop establishment, in the southeastern USA. Many of these studies have used recommended practices for mustard and other small grain crops for the establishment of the rapeseed or canola. In many cases, seeding rates well above necessary rates have been used to insure sufficient crop establishment. This procedure is not economically sound and can result in other problems, such as increased lodging and disease incidence due to small and crowded plants. Cultivars respond differently to seeding depth and the pressure variations associated with packi...