Effect of row spacing and intercrops on phenology, growth and productivity of dual purpose canola oilseed rape (Brassica napus)

Abstract

Precise knowledge of timing of phonological development in a crop assists in better management for achieving its potential productivity. Phenology and productivity of canola oilseed rape after cutting for green fodder under different row spacing and intercropping was studied at two locations in Punjab. Field experiment was laid out in randomized complete block design in three replications with 9 treatments comprising cutting of oilseed rape sown at different row spacings (22.5, 30 and 45 cm) for green fodder and cutting of oilseed rape (sown at 45 and 60 cm row spacing) intercropped with Indian mustard and oats. Oilseed rape and Indian rape (as intercrops) were sown in the last week of September whereas, oats was sown as intercrop after cutting of oilseed rape. Oilseed rape was cut for fodder at 45 days after sowing. Flowering of uncut oilseed rape was early by about 12 days in comparison to crop after cutting. Cutting of oilseed rape delayed the maturity of the crop. Uncut oilseed rape attained significantly more plant height at 90 DAS and at maturity than cut crop. At 90 DAS mean plant height of uncut oilseed rape was 3.39 times higher than the crop cut at 45 DAS. However, at maturity, the uncut crop attained 14.8 % more height than crop cut for fodder. Cutting of the oilseed rape at 45 DAS lowered the LAI at 90 DAS and maturity. Oilseed rape sown at wider spacing of 60 cm resulted in higher LAI than oilseed rape sown at 30 cm row spacing. The PAR interception at 90 DAS was 41.9 % higher than that recorded at 45 DAS due to better canopy development. Intercropping with Indian rape reduced the SPAD value of oilseed rape. The maximum oilseed rape equivalent seed yield was obtained in oilseed rape sown at 45 cm row spacing (cut) + Indian rape (3.56 t ha-1)) which was statistically at par with oilseed rape sown at 60 cm row spacing (cut) + Indian rape (3.41 t ha1 ) but significantly higher than cut and uncut sole crop of oilseed rape (2.22 – 2.71 t ha-1)