Sesame requires fairly hot weather during its growing period. Rapid germi- nation, initial growth, and flower formation are encouraged by a tempera- ture range of 25-27°C. At temperatures below 20°C germination is delayed and seedling growth reduced; temperatures below 10°C stop these processes.
The crop requires a frost-free growing period of about 150 days. Frost at maturity will degrade seed and oil quality, and adversely influence the seed oil constituents sesamolin and sesamin. Severe frost also kills the plants. Sesame is a short-day plant, normally flowering in 42-45 days at 10 hour daylength.
At Tandojam and Sakrand in Sindh, it requires 50-60 days. Sesa- me is reasonably drought-tolerant, and under suitable-conditions, a crop can be produced with as little as 300 rom or as much as 1000 mm annual rain- fall. For an excellent crop, it needs a yearly rainfall of 500-650 mm. Sesame is generally drought-resistant and is grown in rainfed areas. Punjab is the major producer of sesame, having more than 94% of the area under sesame.
Although Sindh has 2.7% of the total sesame area, about 80% of that is confined to Tharparkar District as a rainfed crop. Only 20% of the area is grown under irrigation in Dadu and Hyderabad Districts (Chaudhry 1985). Sesame can grow on a wide variety of soils ranging from light sandy to dark alluvial and coastal plain soils. It prefers light, well-drained soils which can retain adequate moisture. Sesame is as tolerant of salinity as barley, but is susceptible at the seedling stage. It is highly sensitive to sodium chloride but tolerant of sodium sulphide salts. The optimum pH range is 5.5-8.0.
Key Reference : Crop Production by Shafi Mazir