Gibberellic acid mediated co-ordination of calcium and magnesium ameliorate physiological activities, seed yield and fibre yield of Linum usitatissimum L.-a dual-purpose crop.

Commercial cultivation of linseed for both seed and fibre is not keeping pace with increasing demand for linseed products. Although, different strategies are being adopted to produce a dual-purpose linseed crop with good yield of seed and fibre, little progress has been achieved. The present study was carried out to investigate whether application of gibberellic acid (GA3) along with CaCl2 and/or MgSO4 could ameliorate the seed yield in three linseed genotypes 'Parvati', 'Shekhar' and 'Shubhra' without compromising the fibre production. Before sowing the seeds of linseed genotypes were soaked for 8 h in 10(-6) M GA3. Forty days after sowing (DAS), the plants were sprayed with 10(-6) M GA3 along with 2 kg Ca/ha (Ca2) and/or 0.5 kg Mg/ha (Mg0.5). Treatments comprised of (1) 10(-6) M GA3 + Ca0Mg0 (control, T0); (2) 10(-6) M GA3 + Ca2Mg0 (T1); (3) 10(-6) M GA3 + Ca0Mg0.5 (T2) and (4) 10(-6) M GA3 + Ca2Mg0.5 (T3). Performance of the crop was assessed in terms of growth characteristics, physiological and biochemical parameters at 60 and 75 DAS and yield and quality attributes at harvest. Treatment T3 proved best, it enhanced dry weight per plant by 38.2 and 20.6%, P N by 20.7 and 19.1% and gs by 18.2 and 8.8% at 60 and 75 DAS, respectively and seed yield by 39.6%, oil yield by 46.9% and fibre yield by 36.9% at harvest. Further, a decrease in lodging by 13.9% was recorded. Of the three genotypes tested, all exhibited significant difference for all the parameters studied, except for leaf-N content, biological yield and iodine value which showed no difference. However, 'Shubhra' performed better than 'Parvati'.