Abstract:
A field experiment was conducted to study ‘effect of silicon nutrition on physiological and biochemical parameters of maize at different dates of sowing’ during
Kharif 2018 at Main Agricultural Research Station (MARS), University of Agricultural Sciences Dharwad, Karnataka, India. The main plot treatments consist of three dates of sowing (DS
1: Second fortnight of June, DS
2: First fortnight of July, and DS
3: Second fortnight of July) and the sub plot treatments consist of three rates of soil application of Potassium silicate (S
1, S
2 and S
3) and two rates of Foliar application of silicic acid (S
4 and S
5) spray at 45 DAS along with recommended dose of fertilizers and absolute control. Sowing of maize at second fortnight of June recorded significantly higher relative leaf water content (62.0 and 55.7% at 60 and 90 DAS, respectively) over other dates of sowing and soil application of Potassium silicate @ 60 kg ha
-1 recorded significantly higher relative leaf water content (61.4 and 55.0% at 60 and 90 DAS, respectively) as compared to other treatments. The proline content (0.390 µg g
-1) of maize recorded lower at sowing of maize at second fortnight of June with foliar application of silicic acid at 0.50 per cent than all other treatment combinations, RDF and absolute control. Soil application of potassium silicate @ 60 kg ha
-1 and sowing of maize at second fortnight of July recorded significantly lower transpiration rate (4.01 m mole of H
2O m
-2 s
-1at 60 DAS) and higher stomotal conductance (0.588 µ mole m
-2 s
-1) than all other treatment combinations, RDF and absolute control. Significantly higher total soluble sugars content (23.9 mg g
-1) was recorded with sowing of maize at second fortnight of June with soil application of potassium silicate @ 60 kg ha
-1 over all other treatment combinations, RDF and absolute control. However, these parameters were on par with sowing at second fortnight of June with foliar application of silicic acid at 0.5 per cent. Sowing of maize at second fortnight of June recorded significantly higher starch (45.0 mg g
-1) over other dates of sowing and soil application of potassium silicate @ 60 kg ha
-1 recorded significantly higher starch content in maize grain (43.5 mg g
-1) than other treatments. However it was on par with soil application of potassium silicate @ 40 kg ha
-1 (42.5 mg g
-1) and with foliar application of silicic acid at 0.50 per cent (43.0 mg g
-1).