Year : 2018, Volume : 14, Issue : 1
First page : ( 169) Last page : ( 173)
Print ISSN : 2230-9047. Online ISSN : 2231-6736. Published online : 2018  1.

Performance evaluation of submergence tolerant rice varieties through on farm trails in assam

Bezbaruah Ranjita^1,*

¹Krishi Vigyan Kendra, Assam Agricultural University, Jagiroad, Morigaon-7812410, Assam

*Corresponding author email id: reetamishra2010@rediffmail.com

Received:  00  December,  2018; :  00  February,  2019.

ABSTARCT

Flash flood or submergence is a common phenomenon in rice growing rainfed lowland areas of Assam that seriously affects crop establishment leading to severe yield losses. A few submergence-tolerant winter rice varieties have been developed by introgressing SUB1 gene into mega rice varieties such as Ranjit Sub 1, Bahadur sub 1, Swarna sub 1 and IR64 sub 1. Ciherang sub 1 is another variety also is recently under trail for flood affected areas of Assam. On Farm Trails (OFT) were conducted at Nalbari district during 2013–15 and at Morigaon district during 2016–17 with these lines under rainfed lowlands situation of farmers’ field along with local and improved variety as check with an objective to evaluate the performances of these submergence tolerant rice varieties. The varieties with Sub1 survived after complete submergence for up to 9 to 12 days, whereas varieties without Sub1 did not survive and wherever survived show very low yield. The varieties with sub 1 gene Ranjit Sub 1, Bahadur Sub 1 and Swarna Sub1 have shown 100 per cent, 100 per cent and 32.47 per cent more yield respectively when compared with local check. During 2016, the varieties Ranjit Sub 1 and Bahadur Sub 1 were under flood water continuously for 12 days and local check couldn't survive whereas the varieties during 2013–2014 were under flood water for 9 -10 days at tillering stage of the crop. The extension gap for varieties were found in the range of 6.81 to 56 q ha⁻¹ against the local check. Technology gap for varieties were found in the range 6 to 18.22 q ha⁻¹ and 9.1 to 21.1 q ha⁻¹ during comparison with local checks and submergence tolerant rice varieties as check respectively. Similarly technology index showed the variation of 6.67 to 35.17 percent. Overall the result indicated the scope of submergence tolerant rice varieties would help to enhance their production even after flood affects. The economic analysis also resulted higher net return due to the new varietal adoption with higher yield from Rs. 17043.00 to Rs. 45000.00 ha⁻¹ against the net return values Rs 13557 to Rs 21144 ha⁻¹ from check varieties. The results suggest that rice varieties with Sub1 have great potential and sustainable for improving the productivity of rainfed lowland rice prone to flash flooding.

Top

Keywords

Flash-flooding, Rainfed lowlands, Rice, Sub1, Submergence.

Top