Boron fertilizers borax and colemanite application on rice and their residual effect on the following crop cycle

Figures & data

Table 1 Available boron (B) in soils (B mg kg⁻¹) collected at different depths after first season harvest for different B sources applied at 3 kg B ha⁻¹ level

	B sources
Soil depth (cm)	Borax	PC	GC	Control
0–15	0.70a	0.85a	0.30a	0.10a
15–30	0.55b	0.60b	0.20b	0.07a
30–45	0.40c	0.30c	0.15b	0.05b
Note: Values with the same letter within B source at different depths in rows are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 2 Effect of boron (B) fertilizer rates and sources on number of tillers per plant

Levels of B (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	10.3 c	10.3 b	10.3 a	10.3 C
1	11.6 c	11.0 b	11.0 a	11.2 C
2	15.0 b	16.0 a	12.0 a	14.3 B
3	17.6 a	17.2 a	12.1 a	15.7 A
Mean of B source	13.7 A	13.6 A	11.3 B
Note: Values with the same capital letter within means of columns and rows and values with the same small letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 3. Effect of borob (B) fertilizer rates and sources on number of spikelets per panicle

Levels of B (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	90.6 b	90.6 c	90.6 a	90.6 C
1	96.0 b	96.0 c	93.0 a	95.0 C
2	129.0 a	109.6 b	94.6 a	111.1 B
3	135.0 a	133.0 a	100.0 a	122.6 A
Mean of B sources	112.6 A	107.0 B	94.5 C
Note: Values with the same capital letter within means of columns and rows and values with the same small letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 4 Effect of boron (B) fertilizer rates and sources on plant straw yield (kg m⁻²)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	3.2 c	3.2 c	3.2 a	3.2 C
1	3.9 b	3.4 c	3.3 a	3.5 B
2	4.2 a	3.7 b	3.3 a	3.7 B
3	4.4 a	4.3 a	3.5 a	4.0 A
Mean	3.9 A	3.6 B	3.3 C
Note: Values with the same capital letter within means of columns and rows and values with the same small letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 5 Effect of boron (B) fertilizer rate and source on rice yield (tons ha⁻¹)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	5.8 c	5.8 c	5.8 b	5.8 D
1	6.4 b	6.0 b	5.8 b	6.0 C
2	7.1 a	7.0 ab	6.1ab	6.7 B
3	7.2 a	7.18 a	6.5 a	6.9 A
Mean	6.6 A	6.5 A	6.0 B
Note: Values with the same capital letter within means of columns and rows and values with the same small letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite

Table 6 Residual effect of boron (B) fertilizer rates and sources on the height of plant (cm)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	90.3 b	90.3 b	90.3 b	90.0 C
1	96.2 b	99.4 a	94.5 ba	96.7 B
2	101.5 a	102.7 a	96.3 a	100.2 A
3	102.6 a	105.3 a	98.0 a	102.0 A
Mean of B sources	97.6 A	99.4 A	94.8 B
Note: Values with the same capital letter within means of columns and rows and values with the same small letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 7. Residual effect of boron (B) fertilizer rates and sources on percentage of unfilled grains per panicle (%)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	26.1 a	26.1 a	26.1 a	26.1 A
1	22.5 a	20.7 b	22.2 b	22.5 B
2	20.1 b	19.9 b	20.8 b	20.3 C
3	18.0 c	16.1 c	20.2 b	18.1 D
Mean of B sources	21.2 B	20.7 B	22.3 A
Note: Means with the same capital letter within columns and rows, and values with the same non-capital letter within columns are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular coleman.

Table 8 Residual effect of boron (B) fertilizer rates and sources on 1000 grain weight (g)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	18.3 b	18.3 b	18.3 b	18.3 B
1	19.5 b	19.4 b	19.0 a	19.2 B
2	21.1 ab	21.4 a	20.2 a	21.2 A
3	22.2 a	23.1 a	21.3 a	22.2 A
Mean of B sources	20.2 A	20.3 A	19.7 B
Note: Means with the same capital letter within columns and rows, and values with the same non-capital letter within columns are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 9 Residual effect of boron (B) fertilizer rate and source on boron concentration in grain (mg kg⁻¹)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	6.5 b	6.5 c	6.5 a	6.5 C
1	8.0 b	10.0 b	6.8 a	8.2 B
2	11.0 a	11.5 a	7.5 a	10.0 A
3	12.0 a	12.8 a	8.0 a	10.9 A
Mean of B sources	9.3 A	10.2 A	7.2 B
Note: Values with the same capital letter within means of columns and rows and values with the same non-capital letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.

Table 10 Residual effect of boron (B) fertilizer rate and source on rice grain yield (tons ha⁻¹)

B levels (kg ha^−1)	B sources			Mean of B levels
	Borax	PC	GC
0	6.0 c	6.0 c	6.0 b	6.0 C
1	6.1 c	6.1 c	6.0 b	6.1 C
2	6.5 b	6.6 b	6.3 a	6.5 B
3	7.0 a	7.1 a	6.5 a	6.8 A
Mean of B sources	6.40 A	6.45 A	6.23 B
Note: Values with the same capital letter within means of columns and rows and values with the same non-capital letter within B source at different levels are not significantly different at p = 0.05.
PC, powder colemanite; GC, granular colemanite.