Open Access Original Research Article

Prohexadione-Ca Modifies Canopy, Antioxidant Levels and Enzymatic Activity on Jalapeño Pepper Grown in Greenhouse

H. Ramírez, L. J. Ramírez-Pérez, J. H. Rancaño-Arrioja

International Journal of Plant & Soil Science, Page 319-328
DOI: 10.9734/IJPSS/2015/18488

Aims: The use of growth retardants may be an alternative to improve yield and fruit quality of jalapeño pepper (Capsicum annum L.) growing in greenhouse; particularly when a high antioxidants fruit content is the main goal. Prohexadione calcium (P-Ca) is a bioregulator which reduces vegetative growth and increases antioxidants content in deciduous fruit species. The effect of P-Ca in jalapeño pepper is little known, therefore, the objective of this study was to evaluate the effect of P-Ca on the phenotype and fruit quality nutraceutical on jalapeño pepper hybrid Grande.

Study Design: A Completely Randomised Block Design was used, with four replicates per treatment. The results obtained were analyzed with the statistical program SAS (2009), for Windows version 9.1, and for the analysis of variance and comparison of means, the Tukey (P≤0.05) test was applied.
Place and Duration of Study: The experiment was established at the Universidad Autonoma Agraria Antonio Narro in Saltillo, Coahuila, Mexico, between April and July 2012.
Methodology: When seedlings had reached to 10 true leaves, a first foliar application and 15 days later, a second application of P-Ca at 0, 100, 200 and 300 mg L-1 were conducted.
Results: Application of Prohexadione-Ca reduced the final height and diameter of main stem; as well as yield. The P-Ca caused ripen fruits with significantly increase in the content of capsaicin, total carotenoids, vitamin C and catalase and peroxidase activity. Improvement in fruit quality compensates yield reduction since the benefit:cost (B:C) ratio in P-Ca fruits had a value of 0.46 as a result of a higher market price, whereas in control samples was 0.27.
Conclusion: Prohexadione-Ca has a potential to improve fruit quality in jalapeño pepper hybrid Grande growing under greenhouse conditions.

Open Access Original Research Article

Influence of Organic and Inorganic Fertilizers on Soil Chemical Properties and Nutrient Changes in an Alfisol of South Western Nigeria

D. S. Ogundijo, M. T. Adetunji, J. O. Azeez, T. A. Arowolo, N. O. Olla, A. F. Adekunle

International Journal of Plant & Soil Science, Page 329-337
DOI: 10.9734/IJPSS/2015/18355

Temporal changes in soil organic matter and other chemical properties influence the availability of nutrients to plants with or without the application of fertilizers. For proper soil management, these changes must be accounted for. Pot experiment was conducted to assess changes in soil organic carbon, pH and soil nutrients using both inorganic and organic fertilizers. The experiment was a 2 x 3 factorial experiment arranged in completely randomized design with three replicates, using five soil samples collected from Abeokuta, Igboora, Ikenne, Kobape and Odeda of Nigeria. Maize (var. SUWAN 1) was planted in the pots and grown for three consecutive cycles of six weeks each. Soil samples were analyzed for total N, soil organic carbon (SOC), NH4+-N, NO3--N, available P, K, Na, Ca, Mg and pH at pre-planting, at 6 weeks after planting (WAP). The results showed a decrease in average SOC and total N with time in all the soil types. Decrease in total N with time which could be attributed to the crop utilization, ammonia volatilization and bacteria denitrification was also observed. Addition of poultry manure improved the K, Ca, Na, Mg content of the soil and also present a potential to act as lime especially in short time. Combined application of poultry manure and NPK fertilizer reduced susceptibility of soils considered to acidification. Complementary application of 10 t ha-1 of poultry manure with 120 kg ha-1 NPK 20-10-10 proved to improve the soil fertility.


Open Access Original Research Article

Dynamics of Soil Fungal Population in Herbicide Resistant Canola Fields

Ravneet Kaur, Harvinder S. Syan, Suha Jabaji, Denis Pageau, Jaswinder Singh

International Journal of Plant & Soil Science, Page 338-347
DOI: 10.9734/IJPSS/2015/18828

High yielding and stress tolerant crops are vital for food security needs of a growing population. New approaches are being devised to develop genetically modified (GM) plants suitable for changing climate, resistance to pests and herbicides and enhanced nutrition. Despite having great future promises, the general public and scientific community are concerned about the influence of growing GM plants on the ecosystem and human health. Herbicide-tolerant (HT) crops are among such GM crops which are considered to modify soil milieu by introducing herbicides compounds. Using quantitative polymerase chain reaction (qPCR), we examined the effect of herbicides, glyphosate, glufosinate ammonium sulphate and imazethapyr ammonium, on soil fungal population in the HT canola fields over two consecutive growing seasons (2010 and 2011) at two different locations in Quebec, Canada. Our data indicate that although slight increase in copy number of fungal population was observed after glyphosate treatments, this change was statistically non-significant, even in case of glufosinate ammonium sulphate and imazethapyr ammonium. Thus herbicides in study had no adverse effects on fungal population.


Open Access Original Research Article

Effectiveness of Phosphate Rock Application Methods and Frequencies on Soil Available P and Uptake by the Leafy Vegetable Amaranth

R. R. Minja, J. A. Ngailo, N. E. Mwalukasa, L. S. Kyando

International Journal of Plant & Soil Science, Page 348-356
DOI: 10.9734/IJPSS/2015/18484

Low solubility of phosphate rock (PR) limits its direct application to leafy vegetables. However the low solubility and slow P releasing characteristics contribute to higher residual effect than water soluble P fertilizers. A pot experiment was conducted over three crop cycles at the Agricultural Research Institute Uyole (ARI Uyole) in Tanzania to determine the most appropriate PR application method and frequency for amaranth, a nutritious leafy vegetable. The experiment was laid out in a split plot design with three replications. Frequency of Minjingu phosphate rock (MPR) application constituted the main plots while the application methods were the sub plots. The methods were (i) control (no fertilizer material added), (ii) direct application of MPR, (iii) compost + MPR, (iv) crotalaria green manure + MPR, and (v) NPK (Nitrogen –Phosphorus-Potassium fertilizer) as standard. Frequencies were (i) once in the first crop cycle, (ii) during the first and third crop cycle, and (iii) during each crop cycle. Compost + MPR gave significantly higher fresh weight and dry matter amaranth yield than did other treatments. During the third crop cycle there was significant (P ≤ 0.01) interaction between frequency and method of MPR application on P uptake, plant P content, fresh weight and dry matter yield. There was positive and highly significant (P ≤ 0.01) correlation between soil available P, P uptake, concentration and amaranth yield. The results indicate that application of MPR once during three crop cycles especially when combined with manure could supply adequate levels of phosphorus thus replace the use of soluble P fertilizers in production of short season leafy vegetables such as amaranth.


Open Access Original Research Article

Effect of Plant Density on Growth and Yield of Tomato (Solanum lycopersicum L.) at Thai Nguyen, Vietnam

Nguyen Minh Tuan, Nguyen Thi Mao

International Journal of Plant & Soil Science, Page 357-361
DOI: 10.9734/IJPSS/2015/18573

This study was conducted to evaluate the planting density on growth and yield of tomato fruit to determine the optimum planting density. Plant height, number of leaves per plant, fruit set, number of fruit per plant, fruit weight and fruit yield were recorded. Results indicated that treatment with 35714 plants per hectare had the highest plant height, whereas 25974 plants per hectare gave the lowest plant height. Moreover, 25974 plants per hectare had the best results in fruit set, fruit number as well as fruit weight. Planting density with 25974 plants per hectare gave the maximum fruit yield than the other treatments. It was concluded that 25974 plants per hectare significant improve fruit growth and yield of tomato fruit under field condition.


Open Access Original Research Article

Assessment of Heavy Metal Contamination in Urban Soils of Chittagong City, Bangladesh

M. Alamgir, M. Islam, N. Hossain, M. G. Kibria, M. M. Rahman

International Journal of Plant & Soil Science, Page 362-372
DOI: 10.9734/IJPSS/2015/18424

In order to assess the distribution of heavy metals in the urban environment; concentrations of Cd, Cu, Pb, Mn, Ni and Zn were measured on 21 topsoil samples collected from roadside soils of Chittagong city. The heavy metal concentrations were determined by flame atomic absorption spectrometry after digesting the soils with nitric acid–perchloric acid. Mean Cd, Cu, Pb, Mn, Ni and Zn concentrations of the investigated urban soils are 2.43, 32.63, 7.33, 160.79, 860.33, 139.30 mg kg-1 respectively. Compared to urban soils of some other cities in the world Cu, Cd, Pb, Mn and Zn concentrations were somewhat similar. Ni concentration largely exceeded the maximum allowable concentration (60 mg kg-1) indicating high contamination. Stepwise multiple regression indicated that soil properties was responsible for 37 to 42% variation in Cd, Cu and Pb content and in case of Ni it was only 16%. The main sources of Ni contamination in Chittagong city can be considered as anthropogenic sources.