Regulation of plant Na/K ratio for productivity enhancement in Pokkali rice

Emily Alias, Deepa Thomas, Meera V. Menon, P. Prameela, A.K. Sreelatha

Abstract


Pokkali is a unique rice farming system in coastal saline soils of Kerala. High Na content and the resultant wide ratio between Na and other cations, especially K, within the plant become detrimental for rice crop in these soils. An experiment was conducted at Rice Research Station, Vyttila during kharif 2018 to study the effect of liming and foliar application of K in reducing the Na/K ratio in Pokkali rice, adopting Randomised Block Design with 10 treatments replicated thrice and saline tolerant rice variety Vyttila 8. Treatments included two levels of lime (500 and 1000 kg ha-1) or dolomite (800 and 1600 kg ha-1) alone, and in combination, with foliar spray of sulphate of potash (SOP), 2% at 20 and 40 days after transplanting (DAT), foliar spray of SOP alone and control. The study indicated that application of lime at higher quantity, and foliar spray of SOP had significant influence on reducing the plant Na/K ratio. Number of tillers and panicles per m2, percentage of filled grain and grain yield were found to be higher on lime application @1000 kg ha-1 in combination with foliar spray of SOP, thereby enhancing the economic returns. Correlation analysis showed that grain yield and number of panicles had significant negative correlation with Na/K ratio at flowering. It was observed that flowering stage was the most critical one for maintaining a low Na/K ratio, which could influence the crop yield significantly.


Keywords


Acidity, plant Na/K ratio, Pokkali rice, Salinity

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References


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A KAU publication [CODEN: JTAGEI; ISSN 0971-636X; eISSN 0973-5399]