Open Access Original Research Article

Genetic Variation for Seedling Traits in Hydroponics and Correlated Response with Mature Plant Traits on Acid Soil Field

G. O. S. Ojo, L. L. Bello, S. A. Ayuba

International Journal of Plant & Soil Science, Page 1-8
DOI: 10.9734/IJPSS/2016/25902

Four levels of aluminium activity (0, 5, 50 and 300 μMAl3+) were used to screen soybean seedlings in hydroponics for 3 days (3D) and 13 days (13D). The objective of the research was to determine genetic variation for aluminium stress tolerance in seedlings (primary root length, root and shoot dry weight) and to correlate the hydroponics result with that of mature plants on acid soil field. The four levels of aluminium activity constituted the main plots while 49 soybean genotypes constituted the subplots in a split-plot design, with three replications in both 3D and 13D. Genetic variance was higher than other variance components, leading to moderate to high heritability estimates (56.16 – 92.52%) for aluminium stress tolerance in both 3D and 13D hydroponics media. Genetic Coefficient of variation (GCV) ranged from a very low value of 1.88% for shoot dry weight in 13D hydroponics media to a very high value of 116.39% for primary root length in the 3D hydroponics media with higher phenotypic coefficient of variation (PCV) in 3D and 13D.  The GA for primary root length was high in 13D (95.30%) and very high in 3D (187.37%) compared to very low values (2.71 – 9.01%) observed for the root and shoot dry weights in both 3D and 13D hydroponics media. Significant and highly significant positive correlations were observed between most of the seedling traits in 3D and 13D and between the hydroponics and acid soil field in general. The results of the current study indicate that aluminium stress tolerance in tropically adapted genotypes of soybean is heritable and that there is sufficient genetic variation for selection of seedling traits of the studied population in hydroponics. The results of correlation also implies that a two – stage selection process, beginning with selection of tender seedling root traits at 50/300 µMAl3+ in 3D, to be subsequently followed by selection for root dry weight at 0 µMAl3+ in 13D prior to acid soil field evaluation. Further studies on the activity of manganese and iron on the growth and development of soybean in the presence and absence of aluminium is required.


Open Access Original Research Article

Watershed Prioritization Based on Morphometric Analysis and Soil Loss Modeling in Wadi Kerak (Southern Jordan) Using GIS Techniques

Yahaya Farhan

International Journal of Plant & Soil Science, Page 1-18
DOI: 10.9734/IJPSS/2016/25321

Wadi Kerak catchment, located in southern Jordan, covers an area of 191 km². It is characterized by high soil erosion rates due to recurrent intense rainfall events and possibly climatic change, land use/land cover changes since the 1950s, and the dependence of people across the watershed upon rainfed and irrigated farming. The aim of this research is to determine soil conservation prioritization for thirty one third-order mini-watersheds (MW1-MW31) based on morphometric analysis and soil loss modeling methods. Linear and shape morphometric  parameters have been computed for each mini-watershed on the basis of their value/relationship with erodibility, and rank is assigned in order to obtain compound values for final ranking of the mini-watersheds . Soil loss rates also have been estimated using the RULSE model. RULSE factors (R, K, L, S, C, and P) were calculated in a GIS environment, then multiplied together so as to compile soil loss maps/tables, and to estimate soil loss(ton  ha-1 year-1)for the thirty one mini-watersheds. Based on morphometic parameters and soil loss values, and their rankings, the mini-watersheds have been grouped into five classes: extremely high, very high, high, moderate, and low with reference to their priority for conservation practices and watershed management. Two maps were generated separately and illustrate the prioritization of the mini-watersheds based on morphometric analysis and soil loss modeling. Then an integration of the two maps was conducted to recognize the common mini-watersheds falling under each category of priority. It can be demonstrated that 50% of the mini-watersheds can be grouped under moderate, high, very high and extremely high priority based on both soil loss modeling method and morphometric analysis. Consequently, a considerable number of the mini-watersheds should be prioritized for implementing soil and water conservation measures to ensure future sustainable agriculture.


Open Access Original Research Article

Tomato Responses to Bioregulators Grown under Greenhouse Conditions

H. Ramírez, M. G. Zavala-Ramírez, A. Sánchez-López, P. Aguilar-Zárate, N. Cristobal-Aguilar, R. Rodríguez-García, D. Jasso-Cantú, A. Zermeño-González, J. A. Villarreal-Quintanilla, A. López-Fabian

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/IJPSS/2016/25682

Aims: Greenhouse contemporaneous horticulture demands a permanent use of new technologies directed to improve yield and fruit quality. Although, the use of bioregulators has made an important contribution to agriculture by increasing yield in vegetable and fruit crops grown under open field conditions; little is known on their effects on tomato grown in greenhouse. It would be useful to study how they may influence the behaviour of that crop. This approach could be an alternative for improving yield and fruit quality; in particular the one related to increase the antioxidant content. Prohexadione calcium (P-Ca) is a growth retardant which reduces vegetative growth and increases antioxidants content in deciduous fruit species; whereas gibberellins GA4/7 and 6-benzyl amino purine (6-BAP) stimulate flowering or fruit growth on temperate fruit crops. The effect of these hormones in tomato crop grown in greenhouse is not clear. Therefore, the aim of this research was to evaluate the effects of P-Ca, GA4/7 and 6-BAP on the growth, yield and fruit quality in saladette tomato hybrid "Raptor-F1".

Study Design: A completely randomized statistical design was used with ten replicates per treatment. The results obtained were analyzed with the statistical program R version 2.14.2, for Windows version 8, and for the analysis of variance and comparison of means, the LSD (P≤0.05) test was applied.   

Place and Duration of Study: The experiment was conducted at the Universidad Autónoma Agraria Antonio Narro, Saltillo, Coahuila, México, during the period April - August 2015.

Methodology: When plants showed  floral primordia, a first foliar spray of treatments: control (H2O), P-Ca (50 mg L-1), GA4/7 (50 mg L-1), GA4/7 (100 mg L-1), 6-BAP (50 mg L-1), 6-BAP (100 mg  L-1), GA4/7 (50 mg L-1) + 6-BAP (50 mg L-1) and GA4/7 (100 mg L-1) + 6-BAP (100 mg L-1) was applied to run-off using a hand sprayer. A second application of same dosages was performed 15 days later.

Results: P-Ca inhibited the synthesis of gibberellins A1, Aand A7 at the apex; significantly reduced plant height and increased stem diameter, number of flowers, leaves, fruits, and ratio. GA4/7 at 100 mg L-1promoted firmness and sugar content in fruits; whereas, when combined with 6-BAP at 100 mg L-1increased the content of vitamin C and lycopene in ripen fruits. Although, the yield was not increased by bioregulators, improvement in fruit quality compensated this since the benefit : cost (B:C) ratio in these fruits had a value of 1.9, 1.9, 1.84 and 1.74 for P-Ca, GA4/7, 6-BAP and GA4/7, + 6-BAP respectively against 0.86 in control fruits as a result of a  higher market price.

Conclusion: The bioregulators P-Ca, GA4/7 and 6-BAP provoke positive effects on growth, yield and fruit quality in saladette tomato hybrid “Raptor-F1” growing under greenhouse conditions.

Open Access Original Research Article

The Physical Properties and Micronutrient Status of Mayo-gwoi Floodplain Soils, in Taraba State, Nigeria

P. K. Kefas, M. E. Ukabiala, C. V. Azuka

International Journal of Plant & Soil Science, Page 1-8
DOI: 10.9734/IJPSS/2016/25777

The aim of this research was to study the physical characteristics and the status of micronutrients in floodplain soils of Mayo-Gwoi in Taraba state, Nigeria. A detailed soil survey was conducted at the Mayo-Gwoi floodplain using rigid grid approach. Observations were made at 100m regular intervals. Two profile pits were dug and sampled from each of the three soil mapping units identified. The samples were analyzed and characterized as follows; texture vary from loamy to sandy clay loam, bulk density (1.30 g/cm3), particle density (2.63 g/cm3),  water holding capacity (37.5%), water content at field capacity (36%) and wilting point (24%), zinc (1.0 Mg/Kg), iron (6.3 Mg/Kg), copper (0.5 Mg/Kg) and manganese (6.3 Mg/Kg). These soils showed some evidence of degradation and could be productive if subjected to appropriate management and maintenance.


Open Access Original Research Article

Effects of two Refined Petroleum Products on the Growth Response, Survival and Mineral Nutrient Relations of Sacciolepis africana (Hubb and Snowden)

J. F. Bamidele, I. A. Omakor, M. O. Eguagie

International Journal of Plant & Soil Science, Page 1-11
DOI: 10.9734/IJPSS/2016/24503

This study was carried out to investigate the effect of refined petroleum products (diesel and gasoline, RPPs) on Sacciolepis africana (Hubb and Snowden). The parameters measured include number of leaves, plant height, biomass production, chlorophyll content index, leaf area and mineral nutrient content. The refined petroleum concentrations used were 0.2, 0.4, 0.6 and 0.8% (v/w). The results showed that leaf and biomass production, chlorophyll content index and mineral nutrients were significantly reduced (P<0.05) in S. africana when exposed to all concentrations of the RPPs for eight weeks. A gradual decrease in height of the test plant was also noticed. Leaf area was reduced as concentration increased. The effects were concentration and medium dependent. RPP of gasoline had more toxic effect on the test plant. The leaves of the test plant also showed signs of chlorosis and wilting. This study has been able to demonstrate that S. africana can play a role in phytoremediation at low levels of pollution and also that the test plant can act as a bio indicator of polluted water body. It is recommended that proper measures be put in place to prevent release of these products into the environment where it can adversely affect plants thus disrupting the ecosystem balance.


Open Access Original Research Article

Estimation of Regional Evapotranspiration Based on Tri-Angle Method Using Thermal and VNIR Data

E. M. Baioumy, M. A. El-Shirbeny, M. Y. El-Ansary, M. A. Awad

International Journal of Plant & Soil Science, Page 1-15
DOI: 10.9734/IJPSS/2016/24674

Evapotranspiration is a critical component in the hydrological cycle, water resources management and climate studies especially in arid and semi-arid regions. This paper aimed at producing a simplified and applicable procedure for estimating spatial distributed daily actual evapotranspiration (ETa) directly at regional scale using thermal and visible-near infra-red (VNIR) data. The findings of this study will be useful for irrigation water management, climate change studies and water resources planning in the study region. Triangle method, which makes a parameterization of priestly-Taylor equation, was used to estimate ETa at daily scale directly by using a simplified approach with realistic hypotheses. This study conducted in Egypt, Salhia, 6th of October Company as an arid region over the winter crops (wheat, potato and sugar beet) cultivated there using multi date Landsat images. The results were compared with ETvalues adjusted from crop evapotranspiration ETc “FAO Penmamn-Monteith approach” using the Crop Water Stress Index (CWSI). The results showed high accuracy and good agreement against assessment method. The correlation factor (R2) values for wheat, potato and sugar beet were 0.88, 0.98 and 0.99 and Root Mean Square Error (RMSE) were 0.2, 0.26 and 0.37 respectively over the different dates. In the 16th of April, 2014 there was a significant difference in wheat curves as the RMSE were 0.8 and we explained the reasons of this difference as it is a result of the sprinkler irrigation system effect on the mature wheat. This results show that the proposed procedure is accurate enough at least in most cases of our study for estimating the regional surface ETa but it need to evaluate for wheat under other irrigation systems like surface or drip irrigation systems .