Effects of Sowing Dates and Weed Management Practices on Growing Degree Days, Helio Thermal and Photothermal Units of Summer Sesame in Some Parts of India

The present study aimed to determines the effect of dates of sowing and weed management practices on summer sesame in new alluvial zone of West Bengal. For synchronizing different stages of plant growth with environmental conditions, the appropriate sowing date is considered one of the most important determining factors for obtaining optimum yield. Sesame is considered as a drought tolerant crop therefore mainly grown as dry land crop especially in Indian sub-continent where sowing time is dependent upon the availability of moisture, therefore sowing is delayed. A field experiment was conducted during the summers of 2022 and 2023 at the Instructional Farm, Jaguli. Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, West Bengal, India. The experiment was laid out in a split-plot design with three main plot treatments (dates of sowing) and eight subplot treatments (weed management practices) replicated thrice. The sesame variety ‘Savitri was chosen for the experiment. Results indicated that only the thermal indices (growing degree days, helio thermal units, and photothermal units) of sesame were significantly influenced by the dates of sowings. Weed management practices and interaction between dates of sowing and weed management practices were found to be non-significant. Among the dates of sowings, sowing on March 22nd recorded maximum growing degree days (1811.10 °C), helio thermal units (13244.85 °C hour), and photothermal units (22695.76 °C hour), and the minimum was recorded at sowing on February 21st. Significant effect of sowing date on photothermal units of sesame was noticed for all the five phenophases as well as entire life cycle in the study and summed PTU for entire life cycle followed the same trend of as of summed Growing degree days (GDD) and summed Helio thermal units (HTU) for entire life cycle.