Size of samples for nutritional status assessment of mango trees.
Rozane D. E., Natale W., Prado R. de M., Barbosa J. C.
Author Affiliation: Depto. Solos e Adubos, Universidade Estadual Paulista, Fac. de Ciências Agrárias e Veterinárias, Via de Acesso Prof Paulo Donato Castellane, s/n. 14870-000, Jaboticabal-SP, Brazil.
Revista Brasileira de Fruticultura 29 : 371-376
Abstract : Of all the processes used in foliar evaluation, sampling is currently still the most subject to error. To corroborate this, the present study aimed to determine the size of foliar samples and error variation of samples collected from mango tree leaves. The study used four different treatments which consisted of a leaf from each of the cardinal points from 5, 10, 20 and 40 different trees. Mean variation, mean standard error, mean confidence interval and error percentage compared to mean values were calculated based on level of nutrients. Results were calculated by using the semi-amplitude of the interval of confidence expressed as mean percentages. Obtained results led to the conclusion that the chemical evaluation of macronutrients from 10 mango plants would be sufficient for assessment. However, for assessment of micronutrients, the sampling of 20 plants would be necessary, and when considering Fe, a total of 30 plants should be used.