Performance Based Evaluation and Selection of Different Promising Lines of Rapeseed (Brassica Napus L.) for the Shattering Tolerance

Abstract

To evaluate the ten promising lines of Brassica napus against the shattering tolerance, the experiments were carried out in split plot design in the research area of Barani Agricultural Research Institute; Chakwal, Pakistan during two rabi growing season 2011-12 & 2012-13 under rainfed conditions. The main plot was harvested in five different harvesting dates including: HarD₁ = Harvesting at physiological maturity of crop, HarD₂= 7 days after the first harvesting of each promising line, HarD₃= 15 days after the first harvesting of each promising line, HarD₄= 21 days after the first harvesting of each promising line, HarD₅= 30 days after the first harvesting of each promising line. The difference of grain yield (kg/ha) of each promising line in different harvesting dates with compare to its grain yield (kg/ha) in first harvesting date (HarD₁-HarD_i) were measured as indices of shattering. The combine analysis of variance of two year revealed that all the promising lines were significant different for harvesting date, harvesting date x promising lines interaction effect and also year and its interaction effects to each study factors. In the present experiment, the promising line 12CBN008 & 10CBN004 had grain yield 1089 kg/ha & 897 kg/ha respectively. The significant difference of genotypes x harvesting dates confirmed different level of shattering of all promising lines in different harvesting dates. The magnitude of grain yield shattering loss was increased in 4^th and 5^th harvesting dates. On the basis of shattering tolerance among all the promising lines the 11CBN010 was more tolerant to shattering and 11CBN005 were relatively more susceptible to shattering.

Keywords: Rapeseed, Harvesting date, Shattering tolerance