African Journal of Agronomy

African Journal of Agronomy ISSN 2375-1185 Vol. 4 (3), pp. 295-234, March, 2016. © International Scholars Journals

Full Length Research Paper

Use of spectral remote sensing is a reality for the determination of soil attributes

¹Sergio M. Saverin, ²Aryton J. Fernando_,^3* Alberto Carmen Meirelles, ⁴ Machado Anitta Rousseff and Heitor O. Bruna⁵

 ¹Agronomy Department, Universidade Estadual de Maringá, Agricultural Sciences Center , Maringá (PR), Brazil

²Soil Science Department, Escola Superior de Agricultura Luiz de Queiroz/ Universidade de São Paulo. Piracicaba (SP),Brazil.

³Civil Engineering Department, Universidade Estadual de Maringá, Technology Center, Maringá (PR), Brazil.

⁴Agronomy Department, Centro Universitário de Maringá. Maringá (PR). Brazil.

⁵Agronomy Department, Universidade Estadual de Maringá. Agricultural Sciences Center. Maringá (PR). Brazil.

Email: [email protected]

Accepted 14 February, 2016

Abstract

The use of spectral remote sensing is a reality for the determination of soil attributes. This study aimed to evaluate the soil spectral curves of a dataset and infer the possibility of their use for management purposes. For this, soil samples were collected at Rafard/SP in a regular grid of 100 m of edge, totaled 185 points. These samples were submitted to physical, chemical, mineralogical and spectral analyses in individual laboratories. From the results of the analysis was performed to soil classification and organization chart containing the spectral curves for each soil class. Through visual and statistics evaluations were determined, among the 18 land units of area, groups of classes with similar characteristics for both the surface layer and subsurface. These groupings refer, among other attributes, to the original material, constitution textural, mineralogical composition, etc. It is fundamental to the characterization of the area and formulates practicable strategies for better use of it. Thus, it was noted that the analysis of spectral curves can indeed generate information of great practical importance for the management of soils in this region.

Keywords: Spectral curve, soil management, remote sensing.

African Journal of Agronomy ISSN 2375-1185 Vol. 4 (2), pp. 289-294, February, 2016. © International Scholars Journals

Full Length Research Paper

Irrigations, suitable mulching method and nitrogen fertilizer rate for optimum yield and fruit quality of tomato in Nigerian Savanna

^1*E. A. Ngozi, ²J. P. Mailah, Babjide F. G²

¹Nigeria Markets Project

²Department of Agronomy, Ahmadu Bello University, Zaria, Nigeria, 810001.

Email: [email protected]

Accepted 10 January, 2016

Abstract

Field experiments were conducted during 2004/05, 2005/06 and 2006/07 dry seasons at Shika in the Northern Guinea Savanna zone of Nigeria. The treatments consisted of mulching (No mulch, rice-straw mulch and black polythene mulch), nitrogen rates (0, 45, 90 and 135 kg/ ha^-1) and irrigation interval (5, 10 and 15days). These treatments were arranged in a split-plot design with nitrogen and irrigation in the main plot and mulching in the sub-plot. Mulching significantly increased fruit yield, fruit diameter and firmness over the no-mulched treatment. Fruits from plants mulched with polythene were firmest with less unmarketable fruits yield. The application of 90kgN ha^-1 produced higher fruit yield than the control by 115%, 87% and 82% in 2004/05, 2005/06 and 2006/07 respectively. The highest fertilizer rate of 135 kg N/ha^-1 produced the highest yield of unmarketable fruits except in 2005/06 when all the fertilizer rates produced similar unmarketable fruit yields. Increasing the irrigation interval from 5 to 10 days significantly increased fruit diameter and reduced the number of unmarketable fruits while the 15-days interval enhanced fruit firmness.

Keywords: Tomato, Yield, Mulching, Fruit quality, irrigation interval

African Journal of Agronomy ISSN 2375-1185 Vol. 3 (5), pp. 281-284, July, 2015. © International Scholars Journals

Full Length Research Paper

Evaluation of Genotypic stability of maize populations under two different natural soil nitrogen conditions

Akinlolu O. Ohunakin^1* and Alex C. Odiyi ²

¹Department of Plant Science and Biotechnology, Adekunle Ajasin University, PMB 001, Akungba-Akoko, Nigeria.

²Department of Crop, Soil and Pest Management, Federal University of Technology, PMB 704, Akure, Ondo State, Nigeria.

Corresponding author. E-mail: [email protected]. Tel.+234-8035188107.

Accepted 28 June, 2015

Abstract

Five maize populations (TZE 5012, TZE 9030, TZE 9450, SWAN 1 and SWAN 4), were evaluated on performance stability under two natural soil nitrogen conditions viz: 1.57gkg^-1 and 1.74gkg^-1. Data were collected on the productivity potential viz; germination and survival percentage and crop performance including; plant height, leaf area, anthesis-silking interval and total seed weight.  Results showed that lines SWAN 1, SWAN 4 and TZE 9030 had relatively stable productivity and crop performance, above TZE 5012 and TZE 9450. Kernenberg grouping analysis on yield stability and line variability showed that SWAN 1, TZE 9030 and TZE 9450 had relatively stable yield, above TZE 5012 and SWAN 4. While SWAN 1, SWAN 4 and TZE 5012 showed relatively high stability, above TZE 9030 and TZE 9450. Overall performance and stability assessment revealed that SWAN 1 had better responses in both the environment studied; hence it has good genetic traits for adaptation under varying soil nitrogen conditions.

Keywords: Productivity potential, soil nitrogen, crop performance, genetic traits.

African Journal of Agronomy ISSN: 2375-1185 Vol. 3 (4), pp. 272-280, June, 2015. © International Scholars Journals
 
Full Length Research Paper                  

Effect of water and salt stress on the vigor and viability of seeds of pitaya genotypes using different osmotic potential gradients

Alessandra W.F and Felipe V.I.O

Department of Agricultural Sciences, Federal University of Piauí, Av São Sebastião, in 2819, 64,202,020, Parnaíba, PI, Brazil.

*Corresponding author. E-mail: [email protected]

Abstract

Lack of water and salinity are commonly encountered problems in many regions worldwide. For this reason, certain robust cactus species may represent promising crops. Because it is necessary to assess the ability of cactus species to survive and adapt under conditions of natural stress, the present study aimed to evaluate the effect of water and salt stress on the vigor and viability of seeds of pitaya genotypes using different osmotic potential gradients and different osmotically active agents. The experiment had a completely randomized design with a 3 × 6 × 4 factorial scheme corresponding to three pitaya genotypes (white, hybrid I, and hybrid II), six osmotic potential gradients (0.0, -0.2, -0.4, -0.6, -0.8, and -1.0 MPa), and four osmotically active agents (PEG 6000, KCl, NaCl, and MgCl₂), with four replicates. The following variables were analyzed: germination percentage, germination speed index (GSI), and mean germination time (MGT). Statistical analyses were performed for each pitaya genotype. The data pertaining to germination were fitted to a binomial model; the data pertaining to GSI and MGT were fitted to regression models. The germination, GSI, and MGT values for all three pitaya genotypes were optimal with the osmotically active agents KCl and NaCl, regardless of the osmotic potential gradient. At osmotic potential gradients lower than -0.2 MPa, the PEG 6000 polymer was detrimental to pitaya seed vigor and viability. The pitaya hybrid I seeds were more resistant to the adverse conditions, exhibiting higher rates of germination and GSI than those of the other genotypes. The osmotic effect negatively influenced the vigor and viability of seeds of the three pitaya genotypes to a greater extent than the salt effect.

Key words: Cactaceae, Hylocereus undatus, Hylocereus costaricensis, polyethylene glycol, vigor.