Vol. 12, Issue 9 (2023)

Author(s):
Nithin S, Alagesan A, Rathika S, Anuratha A and Saravanan S

Abstract:
A pot experiment to investigate the effect of irrigation water with different levels of salinity prepared by diluting the sea water (44 dS/m) from Bay of Bengal on groundnut in the groundnut growing coastal areas was conducted at State Horticulture Farm, Pushpavanam, Nagapattinam during summer, 2023. The treatments were arranged in Completely Randomised Block Design with three replications and seven levels of irrigation water. The different levels of saline water used for irrigation are T₁ - actual ground water (0.8 dS/m), T₂ – 1 dS/m, T₃ – 2 dS/m, T₄ – 3 dS/m, T₅ – 4 dS/m, T₆ – 5 dS/m, T₇ – 6 dS/m. The soil used for the study was very deep, excessively drained sandy soil. Observations on the number of days for seedling emergence, days to 50% flowering, plant height at harvest, number of branches/plant at harvest, number of pods/plant, number of kernels/pod, pod yield/plant, kernel yield/plant, shelling percentage and haulm yield/plant were recorded. Results revealed that seedling emergence was significantly hindered by higher salinity levels, leading to delayed germination. Plant height at harvest stage exhibited a marked decline with increased salinity, attributed to possible chlorophyll reduction and hindered nutrient uptake. Days to 50% flowering were prolonged under elevated salinity conditions, potentially due to reduced nutrient availability and delayed root development. The number of branches per plant, number of pods per plant, and number of seeds per pod all showed consistent decreases as irrigation water salinity increased. Similarly, both pod and kernel yields per plant were adversely affected by higher salinity, primarily due to reductions in pod number and seed weight. Shelling percentage also decreased with increasing salinity, likely due to decreased kernel weight. Haulm yield per plant exhibited a significant decrease, attributed to reduced growth characteristics influenced by salinity-induced stress. These findings identify the impact of different levels of irrigation salinity on groundnut in the coastal areas.