Effects of supplemental irrigation based on soil moisture levels on photosynthesis, dry matter accumulation, and remobilization in winter wheat (Triticum aestivum L.) cultivars

Figures & data

Figure 1. The soil water content of the top 0–200 cm of the soil (in 20 cm increments) before sowing.

Figure 2. Monthly precipitations in the growth seasons of winter wheat at 2009/2010 and 2010/2011.

Figure 3. Supplemental irrigation amounts at jointing and anthesis stages in 2009/2010 and 2010/2011.

Notes: Rainfed (W0 and W0′), supplemental irrigation (SI) at jointing and anthesis by measuring the 0–140 cm soil moisture layers and bringing the soil moisture to 75%, 65% field capacity (FC) (W1), 75%, 70% (W2) in 2009/2010, bringing the soil moisture to 75%, 75% (W1′), 75%, 80% (W2′) in 2010/2011.

Figure 4. Relative soil water contents in 0–140 cm soil layers after supplemental irrigation in 2009/2010 and 2010/2011.

Note: Rainfed (W0 and W0′), supplemental irrigation (SI) at jointing and anthesis by measuring the 0–140 cm soil moisture layers and bringing the soil moisture to 75%, 65% field capacity (FC) (W1), 75%, 70% (W2) in 2009/2010, bringing the soil moisture to 75%, 75% (W1′), 75%, 80% (W2′) in 2010/2011.

Figure 5. Effects of different treatments on P_n in flag leaves of winter wheat in 2009/2010 and 2010/2011.

Note: Rainfed (W0 and W0′), supplemental irrigation (SI) at jointing and anthesis by measuring the 0–140 cm soil moisture layers and bringing the soil moisture to 75%, 65% field capacity (FC) (W1), 75%, 70% (W2) in 2009/2010, bringing the soil moisture to 75%, 75% (W1′), 75%, 80% (W2′) in 2010/2011. Error bars represent standard errors of the means (p < 0.05).

Figure 6. Effects of different treatments on the actual photochemical efficiency of PSII in flag leaves of winter wheat in 2009/2010 and 2010/2011.

Note: Rainfed (W0 and W0′), supplemental irrigation (SI) at jointing and anthesis by measuring the 0–140 cm soil moisture layers and bringing the soil moisture to 75%, 65% field capacity (FC) (W1), 75%, 70% (W2) in 2009/2010, bringing the soil moisture to 75%,75% (W1′), 75%, 80% (W2′) in 2010/2011. Error bars represent standard errors of the means (p < 0.05).

Table 1. Dry matter accumulation in different organs at anthesis and maturity in 2009/2010 and 2010/2011.

Growing season	Cultivars and treatments	Anthesis			Maturity
		Spike axis + glume (kg ha^−1)	Stem + sheath + leaf (kg ha^−1)	Total (kg ha^−1)	Grain (kg ha^−1)	Spike axis + glume (kg ha^−1)	Stem + sheath + leaf (kg ha^−1)	Total (kg ha^−1)
2009/2010	JM22W0	2375ab	10024a	12400a	7313d	1615d	6677b	15605c
	JM22W1	2022c	9904a	11927a	9465a	1871c	7399a	18735a
	JM22W2	2022c	9904a	11927a	8890b	1943bc	7304a	18138ab
	ZY9369W0	2338b	8714b	11052b	7116d	1264e	5714c	14094d
	ZY9369W1	2496a	9490a	11986a	8856b	2158a	7279a	18293ab
	ZY9369W2	2496a	9490a	11986a	8409c	2028b	7108a	17545b
2010/2011	JM22W0’	1848b	7628c	9476b	7412c	1649c	4914c	13975d
	JM22W1’	2014a	8930a	10944a	9386a	1865a	6587a	17838a
	JM22W2’	2014a	8930a	10944a	9002a	1852a	6508a	17362a
	ZY9369W0’	1079c	4230d	5310c	5794d	1010d	3429d	10232e
	ZY9369W1’	1882b	7929b	9811b	8249b	1788b	5747b	15784b
	ZY9369W2’	1882b	7929b	9811b	7405c	1746b	5553b	14704c

Note: Mean values within columns followed by different letters are statistically significantly different at the p < 0.05 level among treatment conditions for the two cultivars in each growing season.

Table 2. The amounts of dry matter remobilization, accumulation, and their contribution to grains of different cultivars and treatments in the 2009/2010 and 2010/2011 growing seasons.

Growing season	Cultivars and treatments	ADMR (kg ha^−1)	CRDMR (%)	ADMA (kg ha^−1)	CRDMA (%)
2009/2010	JM22 W0	4107a	56.2a	3206c	43.8b
	JM22 W1	2656b	28.1b	6809a	71.9a
	JM22 W2	2679b	30.1b	6211ab	69.9a
	ZY9369 W0	4074a	57.3a	3042c	42.7b
	ZY9369 W1	2549b	28.8b	6307ab	71.2a
	ZY9369 W2	2850b	33.9b	5559b	66.1a
2010/2011	JM22 W0’	2913a	39.3a	4499c	60.7d
	JM22 W1’	2492b	26.6c	6894a	73.5b
	JM22 W2’	2584ab	28.7c	6418ab	71.3b
	ZY9369 W0’	871c	15.0d	4923c	85.0a
	ZY9369 W1’	2277b	27.6c	5972b	72.4b
	ZY9369 W2’	2513ab	33.9b	4892c	66.1c

Notes: ADMA: Amount of dry matter accumulation during grain filling; ADMR: Amount of dry matter remobilization during grain filling; CRDMA: Contribution rate of dry matter accumulation during grain filling; CRDMR: Contribution rate of dry matter remobilization during grain filling. Mean values within columns followed by different letters are statistically significantly different at the p < 0.05 level among treatment conditions for two cultivars in each growing season.

Figure 7. Effects of different treatments on grain filling rate of winter wheat in the 2009/2010 and 2010/2011.

Note: Rainfed (W0 and W0′), supplemental irrigation (SI) at jointing and anthesis by measuring the 0–140 cm soil moisture layers and bringing the soil moisture to 75%, 65% field capacity (FC) (W1), 75%, 70% (W2) in 2009/2010, bringing the soil moisture to 75%, 75% (W1′), 75%, 80% (W2′) in 2010/2011. Error bars represent standard errors of the means (p < 0.05).

Table 3. Grain yield, yield components, and WUE of winter wheat in different cultivars and treatments in 2009/2010 and 2010/2011 growing seasons.

Growing season	Cultivars and treatments	Spike number per ha (×104 ha^−1)	Kernels per spike	1000-kernels weight (g)	Grain yield (kg ha^−1)	Water use efficiency (kg ha^−1 mm^−1)	Irrigation benefit (kg ha^−1 mm^−1)
2009/2010	JM22 W0	653b	30.5d	41.3a	7475d	19.5 cd
	JM22 W1	715a	34.8c	41.5a	9387a	21.6a	20.8a
	JM22 W2	711a	33.1c	41.4a	8922b	20.9 b	12.1b
	ZY9369 W0	446d	48.9b	31.6b	6869e	18.1e
	ZY9369 W1	517c	57.6a	31.8b	8362c	20.0c	17.1a
	ZY9369 W2	510c	56.8a	31.4b	8249c	19.2d	12.0b
2010/2011	JM22 W0’	609b	28.7d	43.7a	7069d	18.9c
	JM22 W1’	725a	34.4c	43.5a	9076a	21.5a	23.3b
	JM22 W2’	722a	33.8c	43.0a	8743b	20.2b	14.8c
	ZY9369 W0’	390d	43.0b	36.0b	5666e	16.3e
	ZY9369 W1’	524c	45.3a	37.2b	7546c	19.7bc	29.1a
	ZY9369 W2’	521c	44.8ab	36.9b	7184d	18.1d	16.8c
Analysis of variance (F value)
Growing season		0.72	210.62**	118.05**	159.44**	31.69**	29.23**
Cultivars		289.34**	2,148.23**	637.53**	463.83**	186.48**	1.01
Treatments		14.87**	41.89**	0.27	229.91**	57.03**	38.14**
Growing season * Cultivars		0.04	172.60**	22.50**	48.34**	5.66*	8.28*
Cultivars * Treatments		0.07	7.40**	0.62	1.71	0.81	1.66

Note: Mean values within columns followed by different letters are statistically significantly different at the p < 0.05 level among treatments for two cultivars in each growing season.

*p < 0.05, **p < 0.01.