Open Access Original Research Article

Assessing Flood Tolerance Potential of Papaya Germplasm at the Juvenile Stage

Isaac Osei-Bonsu, Beloved Mensah Dzomeku, Kwasi Bonsu Offei, Michael Kwabena Osei, Kennedy Agyeman, Seth Obosu Ekyem, Joseph Nketiah Berchie

International Journal of Plant & Soil Science, Page 1-14
DOI: 10.9734/IJPSS/2016/20191

Aims: To assess flood tolerance potential of papaya germplasm and determine physiological basis of observed tolerance.

Study Design: Both Experiment 1 and 2 were in RCBD with 2 and 3 treatments respectively.

Place and Duration of Study: Experiments were conducted in a screen-house at the Kwadaso Station of Crops Research Institute, Ghana between February and September 2014.

Methodology: Six weeks old seedlings of 30 papaya accessions were subjected to 90% partial flooding (F90) by standing planting bags with seedlings in 15 L bucket filled with water up to 90% of height of soil level in bags. Control (non-stressed: NS) plants were watered regularly for 1 week. Post flooding recovery of seedlings was monitored for 1 week. In Experiment 2, seedlings of 6 papaya accessions were subjected to 100% flooding (F100) or 50% partial flooding (F50) for 5 weeks, and a post flood recovery period of 6 weeks. Plant height, girth and biomass were measured together with leaf SPAD chlorophyll content, chlorophyll fluorescence, RWC and senescence.

Results: None of the 30 papaya accessions had high flood tolerance potential, with 60% of accessions studied having low flood tolerance. F90 plants had reduced height and girth relative to control (p<.001). Leaf senescence was high in F90 plants (p<.001). All six accessions used in Experiment 2 could not withstand 100% flooding longer than 3 days. F50 treatment increased lateral root biomass (p<.001), although controls had higher tap root (p<.001), total root (p=.02) and total plant biomass (p=.002) than F50 plants. Leaf RWC (p=.89), SPAD chlorophyll content (p=.05) and chlorophyll fluorescence (p=.24) were not negatively affected by F50 treatment.

Conclusion: None of the papaya accessions studied was able to withstand complete flooding. However, most could tolerate partial flooding of roots for 5 weeks and resume normal growth after release from flood stress.

Open Access Original Research Article

Temporal Variability of Soil Physico-chemical Properties under a Long-term Fertilizer Trial at Samaru, Northern Guinea Savanna of Nigeria

A. H. Girei, N. Abdu, A. Abdulkadir

International Journal of Plant & Soil Science, Page 1-10
DOI: 10.9734/IJPSS/2016/22161

Studies on the effect of long term land use management practices on the temporal variability of soil properties are limited. This study addressed the temporal variability of soil properties under a long term fertilizer trial in a northern guinea savannah of Nigeria. The long-term dung (D), nitrogen (N), phosphorus (P), potassium (K) trial popularly referred to as DNPK experiment at Samaru is about the oldest manure and mineral fertilizer experiment in West Africa modeled after Rothamstead long-term trials in the United Kingdom. It has been under continuous cultivation from 1950 to 2008 from when it was fallowed up till now. Data on soil physico-chemical properties from previous studies conducted on DNPK experiment were synthesized for this work as well as data from the present work to create a time series graph using Microsoft excel to monitor trend of variability of each property over a long term. The contribution of dung to organic carbon appears to supersede any other treatment across all the years. Soil pH showed a decreasing trend with time with increasing rates of Nitrogen fertilization than other treatments. No significant influence of fertilizer management was observed for soil bulk density of the plots across the study years. Saturated hydraulic conductivity and aggregate stability improved when the plots were under cultivation for all fertilization regimes than when they were under fallow due to compacted soil aggregates. This study highlighted the sustainability of integrated nutrient management in sequestering carbon as well as maintaining soil quality over time, and it is therefore recommended as a sustainable management practice for tropical soils.


Open Access Original Research Article

Efficiency of Solubilization of Metals by Mugineic Acid from Sodic Soil

Tomohiro Yoshida, Hiroaki Kudo, Atsushi Sato, Lanpo Zhao, Hongbin Wang, Ankai Xu, Mingqing Zhao, Baolin Qi, Ximing Guo, Shigeru Kamei

International Journal of Plant & Soil Science, Page 1-14
DOI: 10.9734/IJPSS/2016/22571

Iron has limited solubility in alkaline soils and, consequently, alkaline soils may have insufficient available iron for optimal plant growth. Plants of the family Gramineae secrete phytosiderophores, plant-derived compounds such as mugineic acid (MA) that chelate iron, enabling them to extract iron from deficient soils. In the present study, the efficiency of MA and other chelators to solubilize iron and other metals from sodic soil, an alkaline soil, was studied. We measured the amount of solubilized metals from sodic soil, calcareous soil, and andosol. The soils were mixed with the solutions of chelators, incubated with continuous shaking, and centrifuged. The supernatant was filtered and analyzed for metals. In the calcareous soil and andosol, the chelators enhanced solubilization of iron. Although a large amount of iron was solubilized from the sodic soil, the release was independent of the presence of chelators. Similar results were obtained for solubilization of aluminum. When suspended in water, the sodic soil released a considerable amount of silicon, but this was not observed for the other soils. Subsequently, we examined the iron solubilization from salinized or alkalinized andosols by chelators. The results showed that only soil alkalinization enhanced more Fe to be released, and the chelators did not enhance Fe solubilization significantly with increasing soil pH. Because of our results and information of formerly known publications, we suggested that water extractable humic substances caused the iron solubilization from sodic soil. Therefore, we showed the significant information for plant nutrition in sodic soils. Iron, aluminum, and silicon were present in soluble forms in the soil.  Further studies are required to characterize precisely the efficiency of MA on metal nutrients for plants in sodic soils. Furthermore, the risk of aluminum toxicity and the usefulness of water-soluble silicon for plant growth are strongly suggested in natural sodic soils.


Open Access Original Research Article

Effect of Variety and Spacing on Growth and Yield of Maize (Zea mays L.) in Bauchi State, Nigeria

M. U. Sabo, M. A. Wailare, M. Aliyu, J. Sanusi

International Journal of Plant & Soil Science, Page 1-6
DOI: 10.9734/IJPSS/2016/23225

A field experiment was conducted at the Abubakar Tafawa Balewa University teaching and research farm Bauchi state of Nigeria, during the 2013 rainy season, to investigate the effect of variety and intra-row spacing on growth and yield of maize (Zea mays L.) in Bauchi state. The Treatments consist of three varieties of corn (DMR, TZEE and QPM) and three intra-rows spacing (20, 25 and 30 cm). The experiment was laid-out in a randomized complete block design, replicated three times. Data was collected on plant height, number of leaves, leaf area, leaf area index, number of cobs per plot, cob length, 100 seeds weight and grain yield. The results obtained showed that varieties differ significantly, in which, DMR significantly produced the highest yield, and followed by QPM and TZEE which are similar in yield performance. Intra-row spacing of 25 cm was observed to be significantly (p=0.05) higher than 20 cm and 30 cm spacing in all the characters studied. Based on the results of the study, it may be concluded that DMR variety and 25 cm intra-row spacing proved more promising in the study area.


Open Access Original Research Article

Effect of NPK Fertilizer and Cropping Ratios on Nutrient Uptake and Quality Components of Maize (Zea mays) and Egusi Melon (Colocynthis citrullus)

J. O. Ehigiator, G. O. Iremiren, E. J. Falodun

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/IJPSS/2016/21614

Field trials were conducted in 2009, 2010 and 2011 in the University of Benin, Nigeria to determine influence of NPK fertilizer and varying cropping ratios on nutrient uptake and quality components of maize and egusi melon. Cropping ratios and application of NPK 20:10:10 fertilizer at 600 kg/ha significantly (P<0.01) enhanced the percent oil, protein, N and P in maize grains and egusi melon seeds; except for maize where cropping ratios failed to enhance these qualities relative to the sole maize. Cropping ratios influenced mostly the nutrient uptake by maize grains; while N uptake was highest in sole maize, P (2.10 kg/ha) content was lowest in sole maize. For other nutrients, that is K, Ca and Mg their contents in maize grains was enhanced due to intercropping with egusi melon thus making the egusi melon less competitive with maize for the nutrients.

Increased fertilizer rates (0 to 600 kg/ha) of the NPK 20:10:10 enhanced N and Mg uptake in maize grains in intercrop with egusi melon. The trend was different in nutrient uptake by egusi melon with respect to applied fertilizer. The less uptake of nutrients by the crop may suggest residue of same nutrients for further cultivation.

Open Access Original Research Article

Evaluating the Effects of Chemical Ripening with Fluazifop-p-butyl on Sugarcane (Saccharum officinarum) Yield and Sugar Content

M. Muhwiridzwa, B. T. Manenji, T. Madanzi, W. Mahohoma

International Journal of Plant & Soil Science, Page 1-8
DOI: 10.9734/IJPSS/2016/20596

Ripening in sugarcane refers to an increase in sugar content on a fresh weight basis prior to commercial harvesting. Ripening is often prompted by use of chemicals and environmental cues such as moisture stress. The aim of this research was to determine the effects of Fluazifop- p- butyl, a chemical ripener on sugarcane yield and sugar content. The experiment was laid out as a Random Complete Block Design (RCBD) with five replications. Treatments were: Fluazifop- p- butyl (0.45 lha-1), drying off, Fluazifop- p- butyl (0.45 lha-1) + drying off and the control (no Dry off, no Fluazifop- p- butyl). The experiment was carried out at Triangle Estate which is located in the South East Lowveld of Zimbabwe from March 2012 to May 2012. Data on sugarcane yield, sugar quality (Pol % and ERC %) and sugar yield was collected 56 days after establishment of the experiment. Analysis of variance was done on yield and quality data using Genstat 14thedition. Results showed that there were significant differences (P = 0.05) among treatments on sugarcane yield, sugar yield, Pol% and ERC%. The sugarcane yield was highest for the control where no ripener was used. Fluazifop- p- butyl treatment attained 13.9% lower sugarcane yield relative to the control. Application of Fluazifop- p- butyl resulted in the highest sugar yield which was 35.6% higher than that of the control where no ripener was used. A combination of Fluazifop- p- butyl and Dry of resulted in the highest Pol % and highest ERC %. It can be concluded that Fluazifop- p- butyl is effective in increasing sugar yield although it results in a reduction in sugarcane yield. Combining Fluazifop- p- butyl with Dry off results in increased Pol% and ERC%. There is need for further studies to determine the optimum period from spraying Fluazifop- p- butyl to harvesting of sugarcane as this was only done at the end of the drying-off period.