Effect of seed invigouration on yield enhancement in grain cowpea [Vigna unguiculata (L.) walp]

Field experiment was conducted at Coconut Research Station, Balaramapuram with an objective to assess the effect of seed invigouration with zinc sulphate and borax on grain cowpea and to evaluate its effect along with Trichoderma viride on field emergence, growth, yield attributes and yield of the crop. Field emergence percentage was significantly influenced by seed invigouration and an enhancement in the germination percentage of 20.54 to 27.79 was observed compared to control. Seed priming with ZnSO₄ @ 0.05% for 4h recorded higher values of the growth attributes viz., green leaves per plant, branches per plant and dry matter production per plant. Yield attributes viz., pods per plant, pod weight per plant, pod length, pod girth and seed yield ha⁻¹ were recorded the highest in seeds primed in ZnSO₄ @ 0.05% for 4 h. Net returns and B: C ratio were also found to be the highest in the treatment, seed priming with ZnSO4@ 0.05% for 4 h. Hence it can be concluded that, seed priming with ZnSO₄ 0.05% for 4 h can be recommended for better plant establishment, higher seed yield and net returns in grain cowpea.