UTILIZATION OF UNIFORMITY TRIALS TO ESTIMATE OPTIMUM PLOT SIZE AND SHAPE AND NUMBER OF REPLICATIONS IN MAIZE YIELD TRIALS
Abstract: In this work, two uniformity trials were carried out during 2011(1st) and 2012 (2nd) summer seasons in the experimental field of Sids Agric. Res. Sta., ARC. The main objectives were to estimate the optimum plot size and shape and detect the optimum number of replicates for field research experiments on maize yield trials using white maize single cross 10 as plant material. The cultivated area of each field trial was divided into 12 strips; each consisted of 48 rows of 3.0 m long and 70 cm apart. Two statistical methods being soil variability index and maximum curvature were used to estimate optimum plot size and shape using the yield data of 576 basic units which were separately harvested and recorded from each basic unit (row) 2.1 m2. Results revealed that the increasing of plot size decreases the variance per basic unit and the coefficient of variability, but the reduction was not in proportion with the plot size increases. The values of soil variability index were 0.8984 and 0.7422 for 1st and 2nd seasons, respectively. The relationship between the coefficient of variability (C.V.) and plot size (x) was mathematically expressed by the equation: C.V. = 34.2 X -0.6107 in the 1st season and C.V. = 26.5 X – 0.4216 for 2nd season. Accordingly, the optimum plot size was 9 and 3 basic units (1/222 and 1/667 fed.) for 1st and 2nd seasons, respectively using soil variability index, while it was 7 and 9 basic units (1/286 and 1/222 fed.) when maximum curvature method was applied. On the other hand, the long and narrow plots, for a specified plot size, had the lowest variances in the 1st season while the short and wide plots were more efficient in the 2nd season. The required number of replications for detecting a 15% difference among treatment means was 3 to 11 and 4 to 10 in the 1st and 2nd seasons, respectively. While for detecting a 20% difference among treatment means, 2 to 6 replications in the 1st season and 2 to 5 in the 2nd season would be necessary
Publication year 2013
Pages 379-388
Organization Name
Author(s) from ARC
External authors (outside ARC)
    شابون عبد العزيز منصور شابون قسم بحوث الذرة الشامية - معهد بحوث المحاصيل الحقلية
Publication Type Researsh & Applied Activities
↑