Vol. 11, Issue 2 (2022)

Author(s):
BS Bishoyi, B Duary, SS Nanda, UK Behera and C Patra

Abstract:
A field experiment was conducted at the Instructional Farm of the College of Agriculture, Chiplima, Sambalpur, Odisha during kharif seasons in the year 2020 where submergence tolerant rice (Cultivar ‘Swarna sub 1’) was taken as test crop to investigate the effect of nursery management on seedling vigour and post flood survival of rice (Oryza sativa L.) as well as to study its subsequent effect on yield and economics under submergence. Application of fertilizers and sowing of the pre germinated seeds were done as per the treatments. The Main field lay out was done as per the nursery lay out. A common Fertilizer dose of N:P₂O₅:K₂O at 80:40:40 kg ha^-1 was applied in the main field. Plants were completely submerged at 10 DAT with a water depth of 1.1 meter for a period of 15 days. From the experimental findings it revealed that application of N:P₂O₅:K₂O at 100:40:40 kg ha^-1 in the rice nursery produced the highest dry matter production plant^-1, seedling length and leaf area seedling^-1 at transplanting in nursery and was comparable with application of N:P₂O₅:K₂O at 80:40:40 kg ha^-1 (25 kg N ha^-1 from FYM at 5 t ha^-1). The lower seeding density of 40 g m^-2 and seedlings of 40 days old registered significantly higher dry matter production, seedling length and leaf area seedling^-1 in nursery than the higher seeding density of 60 g m^-2 and seedlings of 30 days old respectively. The highest survival of plants after de submergence in the main field was recorded with application of N:P₂O₅:K₂O at 80:40:40 kg ha^-1 (25 kg N ha^-1 from FYM at 5 t ha^-1) which was significantly higher than all other lower level of nutrients and higher than all treatments. The lower seeding density of 40 g m^-2 and seedlings of 40 days registered significantly higher post flood survival% than the higher seeding density of 60 g m^-2 and seedlings of 30 days old, respectively. Application of N:P₂O₅:K₂O at 80:40:40 kg ha^-1 (N₂) in the main plot treatment of rice nursery treatment also recorded higher grain yield & straw yield than all other nutrient treatments. The lower seeding density of 40 g m^-2 (D₁) in the nursery and older seedlings of 40 days recorded significantly higher grain yield and straw yield than higher seeding density of 60 g m^-2 (D₂) in the nursery and younger seedlings of 30 days, respectively. Such practices significantly increased the post flood survival of rice leading to record higher grain yield and return rupees^-1 invested of rice in flood prone low land condition.