Experimental dimensions and precision in trials with millet and slender leaf rattlebox

The objective of this study was to determine the optimal plot size evaluate fresh matter in millet (Pennisetum glaucum L.) and slender leaf rattlebox (Crotalaria ochroleuca), scenarios formed by combinations numbers treatments, replicates, levels precision. Fifteen uniformity trials with rattlebox, single cropping or intercropping, were carried out. Fresh evaluated 540 basic experimental units (BEU) 1 m × (15 36 BEU per trial). soil heterogeneity index Smith (1938) estimated. Plot determined method Hatheway (1961) i treatments (i = 5, 10, 15 20), r replicates (r 3, 4, 6, 7 8), d precision (d 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18% 20%). To experiments completely randomized block designs, 5 20 five plots 10 m² usable area are sufficient for differences between 10% overall mean experiment be considered significant at 0.05 probability level.