Plot size and number of replications to assess the vegetable matter in oat

Abstract

The determination of the optimum plot size in agricultural crops is important for obtaining accurate inferences in the treatments in question. This study aimed at determining the optimum plot size (Xo) and the number of replications to evaluate the fresh matter (FM) and the dry matter (DM) of oat and at verifying the variability of Xo among cultivars and sowing dates. Ninety-six uniformity trials of 3×3 m were performed and each assay was divided into 36 basic experimental units (BEU) of 0.5×0.5 m. The 96 uniformity trials were distributed in four cultivars and three sowing dates. At the flowering stage, FM and DM were determined in each BEU. Then, the Xo was determined in each uniformity assay, using the maximum curvature method of the coefficient of variation model. In oat, there is variability of Xo among cultivars and sowing dates to measure FM and DM. For the four cultivars on the three sowing dates, the Xo of 1.66 m2 and of 1.73 m2 are suitable to evaluate FM and DM, respectively. Four replications to evaluate the maximum of 50 treatments in completely randomized design and randomized blocks design are sufficient so that the differences among treatment means of 44.75% of the experiment mean may be significant, using the Tukey test at 5% probability to measure FM and DM in oat.

Plot size and number of replications in Sudan grass

“…For example, to evaluate i=50 with d=30%, 7.93 replications would be needed in both designs (CRD and RBD) (Tables 3 and 4). A similar pattern for these relationships was found by Cargnelutti et al (2014), Burin et al (2015Burin et al ( , 2016, Lavezo et al (2017Lavezo et al ( , 2018 and Chaves et al (2018a, b).…”

“…For the same value of d, the eplications between the two designs decreases with an increase in the number of eater the number of treatments, the closer the number of replications between le, to evaluate i=50 with d=30%, 7.93 replications would be needed in both bles 3 and 4). A similar pattern for these relationships was found by Cargnelutti 5, 2016), Lavezo et al (2017Lavezo et al ( , 2018 and Chaves et al (2018a, b).…”

“…Therefore, although it might be possible to evaluate fresh weight in plots of this size, the high values for CV show that the size is insufficient, as, according to the criteria of Pimentel-Gomes ( 2009), the experiment would have low experimental precision. This reduction in CV for an increase in plot size is expected and widely proven (Paranaíba et al, 2009;Cargnelutti et al, 2014;Burin et al, 2015Burin et al, , 2016Lavezo et al, 2017Lavezo et al, , 2018Chaves et al, 2018a, b). However, the reduction is non-linear and tends to get smaller as the plot size increases (Paranaíba et al, 2009).…”

“…However, for other groundcover plants, the optimal plot size to evaluate fresh weight in black oats was 4.14 m 2 (Cargnelutti et al, 2014), in millet for different periods of evaluation it was 4.46 m 2 (Burin et al, 2015), and in millet for different sowing and cutting seasons, it was 4.97 m 2 (Burin et al, 2016). In white oats the plot sizes for fresh and dry weight were 1.66 m 2 and 1.73 m 2 respectively (Lavezo et al, 2018). The optimal plot sizes to evaluate fresh and dry weight in rye were 3.43 m 2 and 3.82 m 2 respectively (Chaves et al, 2018b).…”

“…The optimal plot size can be determined by the maximum curvature method of the model of the coefficient of variation (Paranaíba, Ferreira, & Morais, 2009), and the number of replications by the methodology described in Cargnelutti et al (2014). These two methodologies have been used to determine the optimal plot size and the number of replications to evaluate fresh weight in black oats (Cargnelutti et al, 2014) and millet (Burin et al, 2015 ;Burin, Cargnelutti, Alves, Toebe, & Kleinpaul, 2016), fresh and dry weight in white oats (Lavezo et al, 2018) and rye (Chaves et al, 2018b), and grain yield in white oats (Lavezo et al, 2017) and rye (Chaves et al, 2018a).…”