Nutripriming with zinc sulphate and borax for early growth and seedling vigour in grain cowpea [Vigna unguiculata (L.) Walp]

The experiment was conducted at Coconut Research Station, Balaramapuram with an objective to study the effect of nutripriming with ZnSO₄ and borax on the early growth and seedling vigour and Zn and B content in grain cowpea. Nutripriming treatments had significant effect on germination parameters. Nutripriming with ZnSO₄ either at 0.025 or 0.05 per cent recorded higher values for the germination parameters. These treatments recorded 19.68 and 18.51 percentage higher germination than control. Germination index was 1.4 times higher in seeds primed with ZnSO₄ @ 0.025 and 0.05 percent and also recorded higher values for mean daily germination and speed of germination. The highest co-efficient rate of germination and germination rate index was recorded by seed priming with ZnSO₄ at 0.05 percent and it was closely followed by ZnSO₄ @ 0.025 percent for 4 h. Nutripriming with ZnSO₄ either @ 0.025 or 0.05 percent recorded the lowest mean germination time and time to reach 50 percent germination and also recorded higher Zn and B content. Vigour index also followed the same trend. Hence it can be concluded that nutripriming with ZnSO₄ either at 0.025 or 0.05 percent can be recommended for early seedling growth, seedling vigour and higher Zn and B content in grain cowpea.