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Response of Maize (Zea mays L.) Hybrids to Diurnal Variation of Vapor Pressure Deficit (VPD) and Progressive Soil Moisture Depletion
Oumarou Abdoulaye Moussa,
Seyni Boureima,
Hassane Bil-Assanou Issoufou,
Yacoubou Bakasso,
Ali Mahamane,
Mahamane Saadou,
Mainassara Zaman-Allah
Issue:
Volume 7, Issue 1, February 2019
Pages:
1-7
Received:
7 December 2018
Accepted:
28 December 2018
Published:
31 January 2019
Abstract: This study investigated the transpiration (TR) response to (i) diurnal changes of vapor pressure deficit (VPD) and (ii) soil dry down in four maize hybrids contrasting for yield performance under drought stress in the field. These four hybrids included a popular local variety P3K and a commercial check SC303 that were found to be drought susceptible. The experiment was carried out in pots at early vegetative stage (8-leaf stage). Results showed an increase of TR with increasing VPD but with significant variations between the hybrids tested. The two susceptible hybrids P3K and SC303 had higher TR over nearly the whole range of VPD values than the two other hybrids, with the largest variation recorded at VPD values above 6 kPa. Regarding the TR response to soil moisture depletion, normalized TR (NTR) of all genotypes reduced with soil moisture depletion for all treatments. In addition, NTR showed a significant reduction for plants that were irrigated at 3 days intervals before the experiment as compared to those irrigated daily. There was a trend of higher water extraction, as evaluated with the fraction of transpirable soil water (FTSW) threshold, in the tolerant hybrids relative to the susceptible ones for the two irrigation treatments. In addition, prior exposure to water deficit tends to lower the FTSW threshold which leads to increased water extraction capacity at lower soil moisture level. These results demonstrate that control of TR under high VPD conditions coupled with high water extraction capacity from progressively drying soil can contribute to drought tolerance in maize hybrids.
Abstract: This study investigated the transpiration (TR) response to (i) diurnal changes of vapor pressure deficit (VPD) and (ii) soil dry down in four maize hybrids contrasting for yield performance under drought stress in the field. These four hybrids included a popular local variety P3K and a commercial check SC303 that were found to be drought susceptibl...
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Effects of Intra-Row Spacing and N Fertilizer Rates on Yield and Yield Components of Tomato (Lycopersicon Esculentum L.) at Harawe, Eastern Ethiopia
Gezu Degefa,
Gebisa Benti,
Mohammed Jafar,
Fikadu Tadesse,
Habte Berhanu
Issue:
Volume 7, Issue 1, February 2019
Pages:
8-12
Received:
26 December 2018
Accepted:
29 January 2019
Published:
21 February 2019
Abstract: Improper plant spacing and nitrogen fertilizer are among the main factors which constrained productivity of the tomato. Due to this gap the experiment was proposed and conducted in Sofi district, Harari People Regional State, Ethiopia in 2016 and 2017 cropping season to investigate the effect of intra-row spacing and nitrogen fertilizer on yield and yield components of tomato. Experimental treatments were nitrogen rates (0, 39, 69 and 99 kg ha-1) and intra-row spacing (25, 30, 35 and 40cm). A total of 16 treatments were arranged in randomized complete block design with three replication. Melkashola Variety was used for the experiment. The results revealed that there were significant (P<0.05) differences for plant height, number of branches, fruit clusters per plant, number of fruits per plant due to nitrogen application. Increasing nitrogen rate from nil to 69 kg ha-1 increased all these parameters. Average fruit weight and fruit yield were significantly (P<0.05) affected due to the interaction effect of nitrogen and intra-row spacing. The highest fruit weight was recorded at 39 kg N ha-1 and 40cm intra-row spacing while the lowest were at 0 N and 40cm intra-row spacing. The highest fruit yield was recorded at 69 kg ha-1 N and 30cm intra-row spacing while the lowest was at 0 N and 40cm intra-row spacing. In conclusion, the application of 69 kg N ha-1and 30cm intra-row spacing recorded highest fruit yield with highest economic returns (270,330 birr ha-1). Based on fruit yield and economic return, combination of 69 kg N ha-1 and 30cm intra-row spacing was recommended for the study area and similar agro-ecology.
Abstract: Improper plant spacing and nitrogen fertilizer are among the main factors which constrained productivity of the tomato. Due to this gap the experiment was proposed and conducted in Sofi district, Harari People Regional State, Ethiopia in 2016 and 2017 cropping season to investigate the effect of intra-row spacing and nitrogen fertilizer on yield an...
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Effect of Intercropping and Compost Application on Yield and Yield Components of Common Bean in North Shewa, Central Ethiopia
Issue:
Volume 7, Issue 1, February 2019
Pages:
13-20
Received:
24 December 2018
Accepted:
21 February 2019
Published:
25 March 2019
Abstract: Common bean is grown for its high nutritive, medicinal and market value in Ethiopia. Lack of soil nutrients and moisture are production constraints in central common bean producing regions of Ethiopia. Field experiments were conducted on two common bean varieties Awash Melka and Mexican 142 at Shewarobit and Ataye in 2016 and 2017 main cropping seasons with the objective of evaluating the effects of intercropping, compost application and their integration on yield and yield components of common bean. The four management options used were compost application, intercropping, their integration and a control. The results of the study revealed that there was a decreasing trend in yield and yield components from the integrated cultural management practices to the separately applied and sole planting of common bean. Row intercropping with compost application increased the mean number of pods per plant by 41.1% compared to sole planting at Ataye in 2016 cropping season. At Ataye, the number of seeds per pod in Mexican 142 variety was higher by 18.1% and 31.3% in 2016 and 2017 respectively than Awash Melka variety. Row intercropping with compost application increased the mean 100-seed weight from 15.2 to 16.2% in both locations and both cropping seasons compared to sole planting. Compost application increased the average yield of common bean from 10.1% to 25.8% in both locations and both cropping seasons compared to sole planting. Relatively lower yield was obtained from intercropping plots than sole plots at both locations and in both seasons. The integration of intercropping with compost application had the highest LER (2.2) at Ataye in 2017 cropping season while the lowest LER (1.52) was found in the row intercropping at Ataye in the same cropping season. The results obtained from this study indicated the cultural management practices were responsible for increment of yield and yield components of common bean in central Ethiopia and in areas with similar agro-ecological conditions.
Abstract: Common bean is grown for its high nutritive, medicinal and market value in Ethiopia. Lack of soil nutrients and moisture are production constraints in central common bean producing regions of Ethiopia. Field experiments were conducted on two common bean varieties Awash Melka and Mexican 142 at Shewarobit and Ataye in 2016 and 2017 main cropping sea...
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Screening Oryza Sativa L. for Salinity Tolerance During Vegetative Stage for the Coastal Region of Niger-Delta Nigeria
Andrew Abiodun Efisue,
Ella Elizabeth Igoma
Issue:
Volume 7, Issue 1, February 2019
Pages:
21-26
Received:
19 January 2019
Accepted:
4 March 2019
Published:
25 March 2019
Abstract: Background and Objective: The coastal region of Niger Delta of Nigeria is favourable for rice production because of the swampy nature, but rice productivity is very low due high level of salinity in the soil. The objectives of this study was to identify promising salt tolerant genotypes for the deployment into this salt stressed region and also for population improvement for salt breeding programme. Materials and Methods: Two potted experiments comprise the same twenty genotypes were established concurrently in coastal soil and controlled sterilized top soil in two replications in a randomized complete block design at the University of Port Harcourt teaching and research farm. Results: Most of the genotypes showed differential response to salinity stress, the protocol used for the screening could be effective as significant difference was observed based on t-test for the two experiments. Salinity scores showed significan negetative association with number of tillers and leaf area index (LAI). Principal component 1 contributed 44.21% and 38.44% of the total variation in the control and coastal soil experiments, respectively. Conclusion: Genotypes IR 84105-5-B-1-B-3 and IR 84105-5-B-1-B-2 maybe promising for deployment into this salinity stressed region. The leave area index and tillering ability of the rice crop are major yield components, their high weight and factor loading values indicate that they are purtative traits for salinity tolerant, which could be used for population development in salinity breeding programme.
Abstract: Background and Objective: The coastal region of Niger Delta of Nigeria is favourable for rice production because of the swampy nature, but rice productivity is very low due high level of salinity in the soil. The objectives of this study was to identify promising salt tolerant genotypes for the deployment into this salt stressed region and also for...
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Category of Resistance, Antixenosis, Antibiosis, and Tolerance to Acyrthosiphon pisum (H.) (Hemiptera: Aphididae) in Selected Lentil Genotypes (Lens Culinaris M.)
Geteneh Mitku,
Tebkew Damte,
Mulatu Wakgari
Issue:
Volume 7, Issue 1, February 2019
Pages:
27-35
Received:
19 March 2019
Accepted:
26 April 2019
Published:
17 May 2019
Abstract: The pea aphid (Acyrthosiphon pisum Harris) is an economically important insect pest of lentil in Ethiopia. The development of pea aphid resistant lentil genotypes with known resistance mechanism is an economical and effective way to manage this pest. Hence, the current study was conducted to determine the mechanisms (antibiosis, antixenosis, and tolerance) of resistance in six lentil (Lens culinaris Medikus.) genotypes to pea aphid. Three released varieties (Alemaya, Chalew, and R-186), three accessions (ILL-2595 and ILL-4422, and ILL-7664) and one susceptible accession were included in this study. A no-choice study was conducted to determine the categories of antibiosis and tolerance while free choice studies were conducted to determine antixenosis resistance mechanism. In the antibiosis test, there were significant differences in life table characteristics and demographic statistics among the resistant and susceptible lentil genotypes. ILL-7664 had high levels of an antibiotic effect than the others. Alemaya had high levels of tolerance to pea aphid. Choice studies indicated the presence of antixenosis resistance in the lentil genotype, Chalew, ILL-2595 and ILL-4422. The evaluated lentil genotypes exhibited different types of resistance mechanism and level of expression. Chalew showed a three mode of resistance, i.e., antibiosis, antixenosis, and tolerance. Further research should concentrate on levels of antibiosis, i.e., toxins and growth inhibitors to A. pisum.
Abstract: The pea aphid (Acyrthosiphon pisum Harris) is an economically important insect pest of lentil in Ethiopia. The development of pea aphid resistant lentil genotypes with known resistance mechanism is an economical and effective way to manage this pest. Hence, the current study was conducted to determine the mechanisms (antibiosis, antixenosis, and to...
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