CANOLA YIELD FORMATION UNDER DIFFERENT SEEDING METHODS AND SEEDING RATES

The aim of the present investigation was to study the effect of seeding methods and seeding rates on yielding ability and yield structure of Brassica napus and Brassica campestris (canola). For this purpose, four separate field experiments were conducted at the Agricultural Experiment and Research Center, Faculty of Agriculture, Cairo University during 2002/2003 and 2003/2004 winter seasons. The experiments were carried out in a split plot design with 4 replications. The main plots were randomly distributed by three seeding methods (broadcasting, drilling in rows 25 cm and 50 cm apart). The sub-plots were devoted to three seeding rates of 1, 2 and 3Kg/fad at each seeding method. Of the main effects on both species, combined data over the two seasons revealed that seeding methods had significant effect on seed yield/fad as well as yield/plant(g) and its contributing traits with some exceptions, while seeding rate effects were only significant for yield/plant(g) and its components in addition to seed oil% of B. campestris only. Considering the interaction between the two factors of study, seeding method appeared to be the major one affecting the canola productivity under the present conditions. Drill seeding of both species either in 25 or 50 cm row spacing at any seeding rate produced higher yield/fad than the broadcasting. Numerically highest yield/fad of both species was produced from drilling at 25 cm row spacing combined with 3 Kg/fad seeding rate. Seed yield/plant(g) and all of its components were significantly affected by the interaction. Yield/plant(g) and siliquae/plant as well as yield and siliquae per main, primary and secondary branches in addition to seed index exhibited linear decrease as seeding rates increased, and this was true for almost all seeding methods. High values of these traits were recorded at lower (1 Kg/fad) seeding rate at any seeding method. The interaction had no significant effect on seed oil % for both species. Yield analysis of individual plant showed that the differences in total yield contribution from the main and lateral branches were mostly due to the species. Brassica. napus plants carrying on average more than 90% of total yield/plant(g) on the main and primary branches, while the contribution of secondary branches varied from 0.01 to 9.4% taking into account seeding methods and rates. In contrast, the contribution of secondary branches of B. campestris accounted for 43.5% as a general mean over the two factors of study. The results overall suggest that drill seeding at 25 cm row spacing combined with seeding rate of 3 Kg/fad should be used for production of both B. napus and B. campestris canola.