Impact of Varying Planting Dates on Agronomic Performance and Quality of Kale Under South Gujarat’s Sub-Humid Climatic Conditions

Abstract

Globally, kale (Brassica oleracea L. var. acephala) is cultivated in temperate and cool climates, with curly-leafed types being the most widely grown for fresh consumption. The study aims to assess the impact of varying planting dates on agronomic performance and quality of Kale under South Gujarat’s sub-humid climatic conditions. A three-year field investigation (Rabi 2021–24) at Navsari Agricultural University, South Gujarat, evaluated six sowing dates of kale (Brassica oleracea L. var. acephala) to identify the optimum planting window under sub-humid tropical conditions. Sowing in the 3rd week of October (T₂) consistently achieved the greatest plant height, leaf number, and yield per plant, plot, and hectare, alongside the highest net economic returns. While the earliest sowing (1st week of October) produced taller plants in early growth stages, it was inferior to T₂ in total yield. Sowing in the 3rd week of October (T₂) produced the highest leaf number per plant and maximum yield per unit area across all years. This mid-October window likely provided the best combination of temperature, soil moisture, and photoperiod for kale. Quality attributes and mineral composition remained unaffected by sowing date, and no major pest or disease incidences were recorded. The study recommends nursery sowing in the 3rd week of October with transplantation of 25-30 days old seedlings to maximise productivity and profitability of kale in South Gujarat.