Growth and yield of sunflower as affected by moisture stress

The present experience was conducted to determine the growth and yield of sunflower as affected by moisture stress at Agriculture Research Institute, Tandojam during 1998. The data was recorded on the different growth and yield characters i.e. plant height (cm), stem thickness, herd diameter (cm), number of seeds per head, weight of seeds per head (g) seed index and seed yield (kg) per hectare. It was obvious from the results that three was highly significant differences between treatment means of all the parameters due to varying irrigation frequencies. The maximum plant height 115.30 cm was recorded under T5 where five regular irrigation were applied with 10 days interval the second and third positions were recorded by T3 (105.75 cm) and T4 respectively. The minimum plant height 96.25 cm was recorded under T1. The maximum thickness of stem of 2.57 cm was recorded under 15 followed by T4 and T3 where the minimum stem thickness of 1.72 cm was obtained under T1 whose only irrigation was applied after 45-days of sawing. The maximum head diameter of 16.69 cm was recorded in case of T5 where five regular irrigations were applied with 10 days interval. The minimum head diameter 10.82 cm was recorded with T1 (one irrigation). The maximum number of seeds per head (741.50) was recorded under T5 (five irrigations) followed by T4 (four irrigations). Similarly the maximum weight of seeds per head (43.03 g) was recorded under T5 (five regular irrigation) followed by 78.9 g. T4 and minimum number of seeds and seed weight per head were recorded and T1 (One irrigation). The maximum seed index (55.33 g) was obtained under treatment T5 whet e five regular irrigations were applied followed by 45.56 g (14) and minimum seed index 42.30 g was recorded under T1. The maximum seed yield (Kg) per hectare was noted (957.50 kg) under T5 (Five replications) followed by 915.30 kg and 631.60 kg (14 and 13) where as minimum seed yield per hectare was recorded under T1 followed T2. After detailed analysis of the results, it can be conducted that sunflower required 4-5 regular irrigations for producing optimum growth and highest seed yield. The 1st irrigation may be provided after 40 days of sowing under prevailing agro climatic conditions of Tandojam.