Influence of transplanting dates on growth dynamics and harvest period of winter greenhouse cauliflower (Brassica oleracea var. botrytis) in Trans-Himalayan Ladakh, India

The study investigated the impact of various transplanting dates on growth, yield, and harvest period of cauliflower (Brassica oleracea var. botrytis) during the winter months within a passive solar Ladakh greenhouse in trans-Himalayan Ladakh region during 2023–24 at DRDO- Defence Institute of High Altitude Research, Leh, Ladakh. Two commercial cauliflower varieties, WS-909 and Amazing, were used with five distinct transplanting dates starting from 4 September 2023, to 14 October 2023 (2023-2024). Despite the extreme temperature fluctuations observed within the greenhouse, curd formation occurred in both varieties across all transplanting dates. The highest gross (1.15 and 0.98 kg), marketable (0.67 and 0.56 kg), and net (0.44 and 0.36 kg) curd weights for WS-909 and Amazing were recorded when transplanting took place on 4 September, 2023. A delay in planting date resulted in a corresponding decrease in gross, marketable, and net curd weights in both varieties. Additionally, increased temperatures in greenhouse contributed to a fuzziness range of 7.6% to 37.5% in harvested curds, which varied according to transplanting date and variety. The delays in transplanting were associated with reduced harvesting durations, decrease in total number of harvests, and, consequently, a decline in overall yield. It is thus suggested that cauliflower be transplanted early during first fortnight of September for optimal yield in this region. Nevertheless, late transplanting ensured availability of fresh cauliflower during peak winter months, and can be traded off with the reduced yield.