Vol. 11, Issue 5 (2022)

Author(s):
Amarshetti Kiran, Patil RP, Begum Yasmeen and Mahantashivayogayya

Abstract:
A field experiment was conducted at Agricultural Research Station, Gangavati, UAS, Raichur, Karnataka, during kharif 2019 to study the physiological approaches to sustain the rice (Oryza sativa L.) productivity under late sown situation (var. RNR-15048). The experiment was laid out in factorial RCBD with three replications, where two dates of transplanting were taken i.e. D₁ (Normal) and D₂ (Late) and six treatments along with control viz., T₁: NPK-19:19:19 (20000 ppm), T₂: 6-BAP (20 ppm), T₃: salicylic acid (250 ppm), T₄: mepiquat chloride (1000 ppm), T₅: borax @ (10000 ppm) and T₆: control. The results of physiological parameters obtained at 65 DAT and biochemical parameters obtained at 55 DAT indicated that D₁ (Normal DOT) showed higher values as compare to D₂ (Late DOT) in all the treatments. Among different treatments, T₁ (NPK-19:19:19 @ 20000 ppm) recorded the significantly greater results of physiological parameters viz., photosynthetic rate (9.20 μ mol CO₂ m^-2 s^-1), transpiration rate (2.10 m mol H₂O m^-2 s^-1), SPAD value (28.42), NDVI value (28.42) and biochemical parameters such as chlorophyll content ‘a’(2.64 mg g^-1 fr. wt.), ‘b’(0.85 mg g^-1 fr. wt.) and total (3.49 mg g^-1 fr. wt.). Whereas the next best treatment was T₂ (6-BAP @ 20 ppm) over rest of the treatments. The highest grain yield plant^-1 (21.55) were recorded in T₁ (NPK-19:19:19 @ 20000 ppm) than other treatments. It was concluded that D₁ (Normal DOT) was the best situation and among foliar application of different agrochemicals T₁ (NPK-19:19:19 @ 2.0%) was found to be the best treatment, it was ideal and economically feasible at 35,45 DAT and at 55 DAT.