Optimizing irrigation frequency and intra row spacing for specific environment is one the major agronomic practices to improve productivity of haricot bean. Hence, a field experiment was conducted to evaluate the effect of irrigation frequency and intra row spacing on growth, nodulation and agronomic performance of haricot bean at Arba Minch during dry season of 2018/19. The treatments consisted of three levels of irrigation frequency based on IW/CPE ratio (0.5, 0.67 and 1.0) with irrigation depth of 60 mm and three intra row spacing (6, 10 and 14 cm) which were factorially arranged in split plot design with three replications. Data were collected on phenological, nodulation, growth, yield and yield related parameters of the crop. The measured parameters were subjected to analysis of variance using SAS software version 9.0. Among the measured parameters, plant height, pod number per plant, dry matter and seed yield were significantly influenced by interaction effect of the treatments. The maximum seed yield (2873.7 kg ha −1) was recorded with interaction effect of irrigation at IW/CPE of 1 and intra row spacing of 10 cm. As for economic analysis, the same treatment combination also resulted in the highest net benefit (11254.1 Ethiopian Birr ha −1) and marginal rate of return (422.1%). Therefore, it could be concluded that irrigating haricot bean at IW/CPE ratio of 1 and planting at 10 cm intra row spacing could maximize both seed yield and economic benefit of the crop in the study area.
Haricot bean (Phaseolus vulagris L.) is an annual crop belonging to the family Fabaceae [
Frequency of irrigation which is largely dependent on crop type, soil and climate is reported to significantly affect grain yield of haricot bean [
In the study area, a number of farmers are producing haricot bean besides tomato and onion to fill food gap and generate income by using irrigation during dry season. Production area of the crop is increasing from year to year [
The study was conducted at Amibara Farm, Arba Minch, southern Ethiopia, located 505 km from Addis Ababa, the capital city of Ethiopia, during the dry season of 2018/2019. The geographical location of the farm is 37˚36'E longitudes and 6˚03'N latitude and at the altitude of 1218 m.a.s.l. Selected properties of soil are described in
The treatments consisted of three levels of irrigation frequency (I1, I2 and I3 corresponding to IW/CPE ratio of 0.5, 0.67 and 1.0) and three levels of intra row spacing (6, 10, and 14 cm), which were factorially arranged in split plot design with three replications. The IW referred to as fixed irrigation depth (60 mm for haricot bean) and CPE was the cumulative pan evaporation (mm). The irrigation frequency was assigned to main plots, whereas intra row spacing was assigned to subplots. Irrigation water (depth) measured by Parshall flume, was delivered to each plot on attaining the given IW/CPE ratio. Nasir variety was selected as a test crop because of its early maturity, better yielding ability, adaptability and wide cultivation in the study area. The size of each experimental main and subplot was arranged by 8 × 4 m and 4 × 2 m with the total area of 32 m2and 8 m2, respectively accommodating 5 rows with 66, 40 and 28 plants per row corresponding to intra
Physical properties | Soil depth (cm) | |||||||
---|---|---|---|---|---|---|---|---|
0 - 15 | 15 - 30 | 30 - 60 | 60 - 90 | |||||
Sand (%) | 12.96 | 12.06 | 10.34 | - | ||||
Silt (%) | 47.15 | 39.20 | 38.00 | - | ||||
Clay (%) | 39.89 | 48.74 | 51.66 | - | ||||
Textural class | SCL | SC | Clay | - | ||||
Bulk density (Mg m−3) | 1.29 | 1.30 | 1.33 | 1.35 | ||||
Porosity (%) | 51.32 | 50.94 | 49.81 | 49.06 | ||||
Parameter | Chemical properties | |||||||
OM (%) | TN (%) | pH (1:2.5) | Av. P (ppm) | EC dS m−1 | CEC (cmol/kg) | |||
Value | 2.88 | 0.21 | 6.37 | 5.57 | 0.23 | 6.45 | ||
Rating | Medium | Medium | Slightly acidic | Low | Salt free | Low | ||
Reference | [ | [ | [ | [ | ||||
OM = Organic matter, TN = Total nitrogen, Av. P = Available phosphorus, EC = Electrical conductivity, CEC = Cation exchange capacity.
row spacing 6, 10, and 14 cm, respectively. The distance between sub plots and replication were 1 m and 2 m, respectively. The outer single rows at both sides of the plot and two plants at both ends of the rows were considered as border plants. Nitrogen and phosphorus were applied at planting time at the rate of 30 kg ha−1 and 20 kg ha−1, respectively.
The data were recorded on days to 50% flowering, days to 90% maturity, plant height (cm), number of branches, total number of nodules plant−1, number of effective nodules plant−1, nodule dry weight plant−1 (g), number of pods plant−1, number of seeds pod−1, dry matter (kg ha−1), 1000-seed weight (g), seed yield (kg ha−1) and harvest index.
Water-use efficiency (WUE) for each treatment was computed by the following relationship:
WUE ( kgha − 1 cm − 1 ) = Economic yield ( kg / ha ) Total consumptive use of water ( cm )
The measured data were subjected to analysis of variance (ANOVA) using SAS software version 9.0. Differences among the treatment means were compared using least significant difference (LSD) test at 0.05 probability level. Correlations among different parameters were carried out by SPSS Software program (version 16).
Economic feasibility of the treatments was ascertained by taking cost and benefit associated with different treatments following the procedures developed by CIMMYT (1988) [
Phenological and Growth Parameters
Main effect of irrigation frequency and intra row spacing significantly (P < 0.05) affected phenological parameters and branch number, whereas, treatment interaction did not show any statistical variation in the parameters. On the other hand, plant height and dry matter were significantly (P < 0.05) influenced by interaction effects of the treatments.
Days to 50% Flowering and 90% Maturity
Both the parameters were significantly (P < 0.05) affected by main effects of irrigation frequency and intra row spacing [
Branch number was significantly increased with increase in irrigation frequency increased and intra row spacing [
Irrigation frequency | Days to 50% flowering | Days to maturity | Branch number |
---|---|---|---|
I1 (IW/CPE = 0.5) | 48.7a | 65.7a | 4.6a |
I2 (IW/CPE = 0.67) | 48.4a | 66.6b | 4.8ab |
I3 (IW/CPE = 1) | 50.1b | 69.7c | 5.3b |
LSD (0.05) | 1.3 | 2.46 | 0.51 |
CV (%) | 1.9 | 2.8 | 9.6 |
Intra row spacing (cm) | |||
S1 (6) | 48.7a | 65.8a | 4.04a |
S2 (10) | 49.1a | 66.7a | 5.12b |
S3 (14) | 49.6b | 69.7b | 5.65c |
LSD (0.05) | 0.73 | 2.46 | 0.48 |
CV (%) | 1.43 | 0.45 | 8.74 |
±SEM | 0.23 | 0.1 | 0.166 |
Means within each column followed by the same letter(s) are not significantly different at P < 0.05; LSD = least significant difference, CV = coefficient of variation, ±SEM = standard error
Plant Height
Increasing levels of irrigation frequency significantly increased plant height for each level of intra row spacing, whereas, the increasing levels of intra row spacing were associated with significant reduction in plant height for each levels of irrigation frequency [
Dry Matter
The maximum dry matter was observed from a combination of frequent irrigation (IW/CPE = 1) with narrow intra row spacing of 6 cm [
resources under closer spacing. Solomon et al. (2012) [
Nodulation
Nodulation parameters responded significantly only to main effect of irrigation frequency but not to main effect of intra row spacing and its interaction with irrigation frequency. All nodulation parameters were significantly increased with increase in irrigation frequency [
[
Yield and Yield Components
Pod Number per Plant
Pod number per plant was significantly affected by main and interaction effects of the treatments. Interaction of frequent irrigation (IW/CPE = 1) and closer intra row spacing (6 cm) produced significantly the highest pod number per plant [
Irrigation frequency | Total number of nodules | Number of effective nodules | Nodule dry weight (g) |
---|---|---|---|
I1 (IW/CPE = 0.5) | 17.40a | 8.80a | 0.10a |
I2 (IW/CPE = 0.67) | 32.96b | 24.15b | 0.23ab |
I3 (IW/CPE = 1) | 63.76c | 47.26c | 0.37b |
LSD (0.05) | 12.6 | 15.02 | 0.17 |
CV (%) | 8.02 | 3.93 | 0.37 |
±SEM | 2.6 | 2.78 | 0.026 |
Means followed by the same letter(s) in each column are not significantly different at P < 0.05, LSD = least significant difference, CV = coefficient of variation, ±SEM = standard error.
Number of Seed per Pod
Significant variation in seed number was observed only due to main effects of irrigation frequency which was significantly increased from 3.50 to 5.23 with an increase in irrigation frequency from 0.5 to 1 [
1000 Seed Weight
Only main effect of intra row spacing was observed to significantly affect 1000 seed weight. Increasing intra row spacing from 6 cm to 10 cm was associated with significant improvement in the parameter ranging from 226.66 to 233.78 g, but further increment in the spacing treatment did not bring variation in 1000 seed weight [
Harvest Index
Harvest index also significantly responded only to main effect of irrigation frequency. Increasing irrigation frequency up to IW/CPE = 0.67 was associated with significant improvement in harvest index ranging from 22.30 to 32.04. But, further increment in irrigation frequency did not show significant variation in the parameter [
Seed Yield
Interaction effect of the irrigation and spacing treatments produced significant variation in seed yield. Significantly minimum and statistically similar values of seed yields were recorded due to interaction effect of the lowest irrigation frequency (IW/CPE = 0.5) with all levels of intra row spacing [
Irrigation frequency | NSP | TSW (g) | HI (%) | Intra row spacing | NSP | TSW (g) |
---|---|---|---|---|---|---|
I1 (IW/CPE = 0.5) | 3.50a | 228.20 | 22.30a | 6 | 4.10 | 226.66a |
I2 (IW/CPE = 0.67) | 4.02b | 230.78 | 32.04b | 10 | 4.25 | 233.78b |
I3 (IW/CPE = 1) | 5.23c | 234.44 | 34.01b | 14 | 4.37 | 233.00ab |
LSD (0.05) | 0.21 | NS | 3.6 | LSD (0.05) | Ns | 6.84 |
CV (%) | 3.74 | 4.04 | 4.04 | CV (%) | 38.7 | 28.8 |
±SEM | 0.09 | 2.22 | 0.83 |
Means within a column followed by the same letter are not significantly different at P < 0.05, NSP = number of seeds per pod, TSW = 1000 seed weight, HI = harvest index, NS = not significantly different at P < 0.05.
6 cm intra row spacing produced statistically similar seed yield (2688.7 kg ha−1) to the former treatment combination. The improvement in seed yield due to irrigation and spacing treatments could be associated with better availability of soil moisture during critical periods resulting in better translocation of photosynthates and accumulation of food into the seeds.
Soil Moisture Depletion (Total Consumptive Use)
The frequent irrigation (IW/CPE = 1) gave significantly higher value of soil moisture depletion compared to less frequent (IW/CPE = 0.67) and least frequent (IW/CPE = 0.5) irrigations both for 0 - 30 cm and 30 - 60 cm soil depths [
Intra row spacing(cm) | Irrigation frequency | ||
---|---|---|---|
I1 (IW/CPE = 0.5) | I2 (IW/CPE = 0.67) | I3 (IW/CPE = 1) | |
S1 (6) | 1036.3d | 1696.3c | 2688.7a |
S2 (10) | 1201.3d | 2045.0b | 2873.7a |
S3 (14) | 1178.0d | 1728.0c | 2031.0b |
CV (%) | 7.47 | ||
LSD (0.05) | 243.03 | ||
±SEM | 79.5 |
Means within each column and rows followed by the same letter are not significantly different at P < 0.05.
Treatment | Soil moisture depletion(cm) | ||
---|---|---|---|
0 - 30 cm depth | 30 - 60 cm depth | Total | |
I1 (IW/CPE = 0.5) | 10.5a | 10.0a | 20.60a |
I2 (IW/CPE = 0.67) | 13.4b | 12.2b | 25.64b |
I3 (IW/CPE = 1) | 19.3c | 16.2c | 35.50c |
LSD (0.05) | 0.68 | 0.34 | 0.89 |
CV (%) | 4.66 | 2.9 | 3.17 |
±SEM | 0.41 | 0.166 | 0.125 |
Within each column values followed by the same letter are not significantly different at P < 0.05, LSD = least significant difference, CV = coefficient of variation, ±SEM = standard error.
Water Use Efficiency (WUE)
Interaction of irrigation frequency and intra row spacing treatments showed significant (P < 0.05) variation in water use efficiency of haricot bean [
Economic Analysis
Result of the economic analysis (after elimination of dominated treatment) showed that application of irrigation water corresponding to IW/CPE = 0.67 and planting haricot bean at intra row spacing of 14 cm gave the lowest net benefit of 5598.4 ETB ha−1 and marginal rate of return of 157.8%, whereas, irrigating the crop at IW/CPE = 1 and planting the crop at intra row spacing of 10 cm resulted in maximum net benefit of 11254.1 ETB ha−1 and marginal rate of return 422.1% [
Treatment combination | Average yield (kg ha−1) | Adjusted yield (kg ha−1) | Gross benefit (ETB ha−1) | Total variable cost (ETB ha−1) | Net benefit (ETB ha−1) | Marginal rate of return (%) |
---|---|---|---|---|---|---|
I2 × 14 cm | 1728.0 | 1555.2 | 10886.4 | 5288 | 5598.4 | 157.8 |
I2 × 10 cm | 2045.0 | 1840.5 | 12883.5 | 5850 | 7033.5 | 255.3 |
I3 × 10 cm | 2873.5 | 2586.3 | 18104.1 | 6850 | 11254.1 | 422.1 |
I2 = IW/CPE = 0.67; I3 = IW/CPE = 1; ETB = Ethiopian Birr.
Combination of frequent irrigation and 10 cm intra row spacing significantly improved seed yield (2873.7 kg ha−1), water use efficiency, net benefit (11254.1 ETB ha−1) and marginal rate of return (422.1%), signifying the possibility of simultaneous maximization of seed yield and economic benefits of haricot bean. Producers in Arba Minch area and elsewhere with similar agro-ecological conditions may, therefore, apply irrigation corresponding to IW/CPE ratio of 1.0 and intra row spacing of 10 cm for higher productivity and profitability of haricot bean. However, this study was conducted for single season at single location using one variety. Therefore, further research should be conducted considering different varieties, inter row spacing, different fertilizer rates and sources repeated over seasons and locations in order to come up with comprehensive recommendations.
We would like to thank Arba Minch University Research Coordination Office College of Agricultural Sciences for partial funding of this research.
The authors declare no conflicts of interest about publication of this paper.
Wube, T., Girma, A. and Sharma, P.D. (2020) Response of Haricot Bean (Phaseolus vulgaris L.) to Irrigation Frequency and Intra Row Spacing at Arba Minch, Ethiopia. Agricultural Sciences, 11, 540-551. https://doi.org/10.4236/as.2020.116034