Tag Archives: cluster analysis

2460–2473 A. Zymaroieva, O. Zhukov, T. Fedonyuk and A. Pinkin
Application of geographically weighted principal components analysis based on soybean yield spatial variation for agro-ecological zoning of the territory
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Application of geographically weighted principal components analysis based on soybean yield spatial variation for agro-ecological zoning of the territory

A. Zymaroieva¹*, O. Zhukov², T. Fedonyuk³ and A. Pinkin⁴

¹Zhytomyr National Agroecological University, Faculty of Forestry, Department of Forest Resources Utilization, Stary Blvd. 7, UA10008 Zhytomyr, Ukraine
²Oles Honchar Dnipro National University, Faculty of Biology and Ecology, Department of Zoology and Ecology, pr. Gagarina, 72, UA49010 Dnipro, Ukraine
³Zhytomyr National Agroecological University, Faculty of Forestry, Department of Forest Ecology and Life Safety, Stary Blvd. 7, UA10008 Zhytomyr, Ukraine
⁴Zhytomyr National Agroecological University, Faculty of Engineering and Power Engineering, Department of Electrification, Automation of Production and Engineering Ecology, Stary Blvd. 7, UA10008 Zhytomyr, Ukraine
*Correspondence: nastya.zymaroeva@gmail.com

Abstract:

In this study, the geographically weighted principal components analysis as an alternative method for agro-ecological characterization of the region was provided. The spatial and temporal distribution pattern of soybean yield was analyzed by using spatial statistics technology, which provided a good reference for agricultural development planning. The soybean yield was selected for the present study because it is a comprehensive indicator reflecting the production potential of the regional agroecosystems. The organized data set, which included the average per year yields of soybean in 10 regions (206 administrative districts) of Ukraine, was used for analysis. The regular temporal trend, specific for each district, was previously extracted from the time series data. The principal components analysis of the detrended data allowed to identify four principal components, which altogether can explain 58% of the soybean yield variation. The geographically weighted principal components analysis allowed to reveal that four spatially determined processes were influencing the yield of soybeans and had the oscillatory dynamics of different periodicity. It was hypothesized that the oscillating phenomena were of ecological nature. Geographically weighted principal component analysis revealed spatial units with similar oscillatory component of soybean yield variation. Our study confirmed the hypothesis that within the studied territory there are zones with the specific patterns of the temporal dynamics of soybean yield, which are uniform within each area but qualitatively different between zones. The territorial clusters within which the temporal dynamics of soybean yield is identical can be considered as agro-ecological zones for soybean cultivation.

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2169-2178 D. Tabti, M. Laouar, K. Rajendran, S. Kumar and A. Abdelguerfi
Analysis of gamma rays induced variability in lentil (Lens culinaris Medik.)
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Analysis of gamma rays induced variability in lentil (Lens culinaris Medik.)

D. Tabti¹*, M. Laouar¹*, K. Rajendran², S. Kumar² and A. Abdelguerfi³

¹Laboratoire d’Amélioration Intégrative des Productions Végétales (AIPV, C2711100) ENSA El Harrach DZ16200, Algiers, Algeria
²Biodiversity and Integrated Gene Management Program. The International Centre for Agricultural Research in Dry Areas, Rabat-Institutes, MA10112, Morocco
³Cité des Annassers 4 Bt 68 N°8 Kouba Algiers, Algeria
*Correspondence: tdahbia1990@gmail.com; m.laouar@ensa.dz

Abstract:

In this study, a lentil variety, Idlib-3, was subjected to 100 Gy (LD50) gamma-ray irradiation. At M2, mutant families were characterized for the most beneficial agronomic traits. High genotypic coefficient of variation, broad sense heritability and genetic advance of the traits such as seed yield per plant and hundred-seed weight indicated expression of additive gene action and confirmed the response at early generation selection. Total number of pods per plant had positive correlation and the highest positive direct effect on seed yield per plant and hence the preference should be given for this trait during selection. The novel mutant families identified with early flowering, early maturity (families 5 and 90) in cluster I, and more first pod height (families 10, 70 and 82) in cluster II could be utilized to breed short duration lentil varieties suitable for machine harvest.

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821-837 P.A. Marziliano, D. Russo, V. Altieri, G. Macrì and F. Lombardi
Optimizing the sample size to estimate growth in I-214 poplar plantations at definitive tree density for bioenergetic production
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Optimizing the sample size to estimate growth in I-214 poplar plantations at definitive tree density for bioenergetic production

P.A. Marziliano*, D. Russo, V. Altieri, G. Macrì and F. Lombardi

Mediterranean University of Reggio Calabria, Department of AGRARIA, Loc. Feo di Vito, IT89165 Reggio Calabria, Italy
*Correspondence: pasquale.marziliano@unirc.it

Abstract:

In Europe, over the last decades, the arboriculture for woody biomass production has significantly expanded, often using poplar plantations. In order to maximize production, the flexibility of the cultivation algorithms becomes necessary. For this reason, it is necessary to apply monitoring tools for the evaluation and estimate of the wood productions, without significantly affect the production costs. In particular, for the estimate of the productions, the choice of the sample size is of particular importance. The aim of this study was to verify a simplified sampling approaches in poplar plantations characterized by constant tree density. The research was conducted in a poplar plantation on the Tuscan hills (Italy). The surveys were carried out each year for 13 years, from 4 to 16 years old. Through different statistical techniques, the change in the social position of each tree over time was evaluated. The results showed that the social position of each tree has been characterized by the first years after the plantation. Consequently, the estimate of the productions can be carried out by analysing the diameter increment of 10% of the trees, included in the diameter classes around the medium-sized tree at the time of the survey. This study provided a valid method for forest managers characterized by a simplified approach useful to estimate the growth and yield of hybrid poplars. This method will permit reliable biomass estimates, but also a reduction of the costs in the sampling activities in the field.

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