Assessment of Performance of Commonly Used Experimental Designs (Randomized Complete Block Design, Lattice Design and Alpha-Lattice Design) in the Ethiopian Agricultural Research System
| dc.contributor.advisor | Taye, Girma (PhD) | |
| dc.contributor.author | Edosa, Bacha | |
| dc.date.accessioned | 2022-03-29T09:19:15Z | |
| dc.date.accessioned | 2023-11-09T14:29:25Z | |
| dc.date.available | 2022-03-29T09:19:15Z | |
| dc.date.available | 2023-11-09T14:29:25Z | |
| dc.date.issued | 2010-10 | |
| dc.description.abstract | The c ho ices of experim enta l des ign as well as o f statistical ana lys is are of great importance in fi e ld experiments. To improve production and productivity of crop yield it is important to employ tested and proven exper imental des ign. The aim of th e study is to eva luate the prec is ion of commonly used experimental des igns (randomi zed complete block des ign, lattice des ign and alpha- lattice des ign) in the Ethiopian agricultural research system. Both fixed and linear mixed effect mode ls were used to compare the effi ciency of experimental des igns. Different variety trials co nducted at different locations by the National and Regio nal Agricultural Research Organization in 2004/05-2008/09 years (seasons) were used in this study. The results indicate that on average the randomized complete block design (RCBD) was more effic ient than complete ly randomized des ign (CRD). For large miss ing va lues in RCBD, the use incomplete block approach is more e ffi c ie nt than using miss ing-estimated approach. A Iso use 0 I' covariance ana lys is for damaged yield in RCBD increased the re lative effic iency of RCBD compared to CRD than the ana lys is without cova riate. The lat tice des ign was more effic ient to increase the prec ision o f agr icultural fie ld experiments than RCBD. The re lative e ffi c iency o f a lpha latt ice des ign compared to RCBD was 101.9% and 102.4% for both data sets respect ively. Th is indicates that researchers ha ve in gcneral correctly co ntro lled the loca l va riability during experimentat ion. However, the cases where blocking was not s ignifica nt can be attr ibuted to technical issues such as orientation a nd di rection of blocking which should be improved by researches in similar experiments. Based on the results we co nc lude that RCBD is more efficient than CRD and lattice and a lpha lattice des igns are more effic ie nt than RCBD. In order to increase the precision of agricultural field experiments researchers are advised to use RCBD for small number of treatments, lattice des ign and alpha lattice desig ns for large number of treatments. | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/30971 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Performance of Commonly Used Experimental Designs | en_US |
| dc.title | Assessment of Performance of Commonly Used Experimental Designs (Randomized Complete Block Design, Lattice Design and Alpha-Lattice Design) in the Ethiopian Agricultural Research System | en_US |
| dc.type | Thesis | en_US |