Yield potentials of improved rice varieties for increased lowland rice production within the mankran watershed in Ghana

Figures & data

Table 1. Initial physico-chemical properties of soils in the experimental sites.

	Adugyama		Biemso No. 1
Parameter/Depth	0–20 cm	20–40 cm	0–20 cm	20–40 cm
Soil physical properties
Sand (%)	76	77	77	77
Silt (%)	10	10	9	13
Clay (%)	15	13	14	10
Textural class	Sandy loam		Sandy loam
Soil chemical properties
pH (H2O)	6.68^b	7.34^a	6.27^b	6.53^a
Total organic carbon (%)	0.94^a	0.48^b	0.71^a	0.44^b
Total nitrogen (%)	0.10^a	0.05^b	0.09^b	0.05^a
Available P (mg kg^−1)	7.62^a	4.70^b	5.40^b	3.68^a
Exchangeable Ca (cmol(+) kg^−1)	5.80^a	4.47^b	3.34^a	2.80^b
Exchangeable Mg (cmol(+) kg^−1)	1.62^a	1.89^a	1.21^a	1.21^a
Exchangeable K (cmol(+) kg^−1)	0.16^a	0.11^a	0.05^a	0.05^a
Exchangeable Na (cmol(+) kg^−1)	0.32^b	0.46^a	0.25^b	0.45^a

Means separated by same lowercase letter across depths for each location are not significantly different at p < 0.05.

Figure 1. Rainfall amount during the major (a) and minor (b) seasons.

Table 2. Characteristics of improved rice varieties evaluated.

Rice variety	ID	Days to maturity	Yield potential (t ha^−1) +
AGRA (Local check 1)	V1	125–130	8.0
Amankwatia (Local check 2)	V2	120–125	8.0
ARS-957-BGJ-171-15-D-B	V3	-	-
FARO 66	V4	125-130	6.7
FARO 67	V5	120-125	6.7
GT 11	V6	118	7.9
NERICA L36	V7	125	7.0
ORYLUX 3	V8	120	6.3
ORYLUX 4	V9	120	6.4
ORYLUX 6	V10	100	6.5
SAHEL 177	V11	122	10
SAHEL 305	V12	124	10
SAHEL 317	V13	122	12
WAB 56-50	V14	108	4
WITA 9	V15	120	10

+ The potential yield corresponds to the maximum yield obtained in experimental fields on-station. [Source: Africa Rice Center]

Table 3. P-values from the analysis of variance on growth and yield parameters for rice varieties for each season.

Variables	No of tillers per m^2	No of panicles per m^2	Plant height (cm)	1000 grain weight (g)	Grain yield (t ha^−1)
Major Season
Variety (V)	0.0000	0.0118	0.0000	0.0000	0.0000
Location (L)	0.0089	0.0028	0.0000	0.0358	0.0000
V*L	0.0002	0.0265	0.0000	0.0419	0.0042
Minor Season
Variety (V)	0.0000	0.0001	0.0000	0.0000	0.0000
Location (L)	0.0841	0.0199	0.0889	0.0047	0.2928
V*L	0.0000	0.0150	0.0000	0.0215	0.0006

Table 4. Growth and yield performance of rice varieties in the Makran watershed during 2020–2021.

Season	Variety\location	No of tillers per m^2		No of panicles per m^2		Plant height (cm)		1000 grain weight (g)
		Adugyama	Biemso No. 1	Adugyama	Biemso No. 1	Adugyama	Biemso No. 1	Adugyama	Biemso No. 1
Major	ARS-957-BGJ-171-15-D-B	193.67aA	188.33aA	151.67^aA	101.00^bB	94.33^dA	91.67^dA	30.33^aA	28.33^aB
	FARO 66	203.00^aA	200.33^aA	149.00^aA	127.00^aA	139.00^aA	116.67^bB	26.67^bA	25.67^bA
	FARO 67	175.00^bA	184.67^aA	116.67^aA	123.33^bA	147.00^aA	130.00^aB	27.67^aA	27.67^aA
	GT11	196.67^aA	173.33^aA	130.00^aA	115.00^bA	131.67^bA	114.00^bB	29.00^aA	28.00^aA
	NERICA L36	175.00^bA	183.33^aA	129.00^aA	121.67^bA	96.67^dA	104.33^cA	28.00^aA	27.00^aA
	ORYLUX3	140.00^cA	170.00^aA	131.33^aA	91.67^bB	122.67^bA	103.33^cB	25.67^bA	25.67^bA
	ORYLUX4	196.33^aA	174.33^aA	159.67^aA	135.00^aA	124.00^bA	94.33^dB	25.67^bA	26.00^bA
	ORYLUX6	224.00^aA	199.67^aA	133.33^aA	95.67^bB	111.00^cA	91.67^dB	24.00^bA	23.00^cA
	SAHEL177	170.00^bA	193.33^aA	141.33^aA	153.33^aA	108.33^cA	109.00^bA	29.00^aA	27.00^aB
	SAHEL305	162.00^bB	201.67^aA	137.33^aA	145.00^aA	105.67^cA	112.00^bA	25.00^bA	25.00^bA
	SAHEL317	106.67^cB	179.67^aA	147.67^aA	138.00^aA	116.33^cA	110.67^bA	26.00^bA	26.00^bA
	WABS56.50	115.33^cA	102.00^bA	145.33^aA	114.33^aA	135.67^aA	115.00^bB	29.00^aA	28.33^aA
	WITA9	102.67^cB	196.67^aA	135.00^aA	136.33^aA	104.67^cA	112.67^bA	24.33^bA	24.33^cA
	AGRA	180.33^bA	174.67^aA	140.00^aA	128.67^aA	125.00^bA	123.33^aA	29.33^aA	29.67^aA
	AMANKWATIA	169.67^bA	174.67^aB	143.67^aA	165.00^aA	128.67^bA	114.67^bB	28.33^aA	28.33^aA
Minor	ARS-957-BGJ-171-15-D-B	149.33^bB	193.33^aA	128.00^aA	121.67^aA	84.00^eA	91.67^dA	28.00^aA	25.33^aA
	FARO 66	158.67^bB	203.33^aA	99.67^aB	148.00^aA	106.00^cA	115.67^cA	24.67^bA	21.00^bB
	FARO 67	161.33^bA	186.67^aA	116.33^aA	117.67^aA	124.67^bA	132.00^aA	25.00^bA	21.33^bB
	GT 11	180.33^aA	170.00^aA	124.33^aA	125.33^aA	101.67^dA	111.00^cA	24.33^bA	25.33^aA
	NERICA L36	149.33^bB	193.33^aA	106.33^aA	132.67^aA	83.00^eB	105.67^cA	26.00^aA	25.00^aA
	ORYLUX 3	151.67^bA	78.00^cB	77.33^aA	82.33^bA	118.67^cA	92.67^dB	22.33^bA	20.33^bA
	ORYLUX 4	155.67^bA	143.00^bA	107.67^aA	87.00^bA	100.00^dA	105.67^cA	23.00^bA	21.67^bA
	ORYLUX 6	173.33^aA	129.67^bB	121.00^aA	90.33^bA	108.67^cA	91.00^dB	22.00^bA	22.00^bA
	SAHEL 177	143.33^bB	173.67^aA	103.67^aA	139.67^aA	108.33^cA	103.00^cA	24.33^bA	26.00^aA
	SAHEL 305	139.33^bA	165.67^aA	103.67^aA	139.67^aA	98.67^dA	72.00^eB	22.00^bA	23.00^bA
	SAHEL 317	186.67^aA	146.00^bB	101.67^aA	126.67^aA	96.67^dA	88.00^dA	23.33^bA	22.67^bA
	WAB 56-50	154.00^bA	146.67^bA	97.67^aA	83.33^bA	136.00^aA	98.00^dB	27.33^aA	23.67^bB
	WITA 9	164.67^bB	209.33^aA	152.33^aA	169.33^aA	93.67^dB	110.00^cA	24.67^bA	22.67^bA
	AGRA	186.67^aA	176.67^aA	122.33^aA	151.33^aA	111.67^cA	119.67^bA	26.33^aA	26.00^aA
	AMANKWATIA	149.33^bB	186.67^aA	118.33^aA	144.00^aA	112.67^cA	113.67^cA	26.67^aA	26.33^aA

Means followed by different uppercase letters within rows (location) and lowercase letters within columns (Varieties) are significantly different (p < 0.05) based on Scott–Knott test.

Figure 2. Grain yield performance of improved varieties at the study locations for two cropping seasons. .

Bars represent standard error of means. Uppercase letters compare means across locations and lowercase letters compare means within varieties for each season. Bars with same letters within varieties and across location are not significantly different based on the Scott Knott test at p< 0.05

Figure 3. The ‘which-won-where’ view of the GGE biplot based on the variety × location data in Figure 2.

Adu1, Adu2, Biem1, and Biem2 represent Adugyama in the major season, Adugyama in the minor season, Biemso No.1 in the major season and Biemso No.1 in the minor season, respectively, and V1-V15 represent improved varieties, respectively. Details of the improved varieties are shown in Table 1.

Figure 4. Mean verses stability (a) and variety-focused scaling (b) for comparing improved varieties and local checks. .

Adu1, Adu2, Biem1, and Biem2 represent Adugyama in the major season, Adugyama in the minor season, Biemso No.1 in the major season and Biemso No.1 in the minor season, respectively, and V1-V15 represent improved varieties. Details of the improved varieties are shown in Table 1.

Figure 5. Farmers’ preference for newly introduced improved rice varieties compared to local checks in the Mankran watershed in Ghana.

Data availability statement

The data presented in this study are available on request from the corresponding author. The data are not publicly available for ethical reasons.