ANALYSIS OF VARIANCE PRECISION FOR THE INDEX LER, USED IN INTERCROPPING EXPERIMENTS, WHEN A CORRETION TO THE STANDARD ERROR IS USED.

Euclides Braga MALHEIROS1

Dilermando PERECIN [1]

§    ABSTRACT: A common practice for the analysis of intercropping experiments the utilization of indices. Lately they have received a great attention, since they present distributional problems, compromising in same cases the tests of hypothesis. The precision of the analysis of variance of the LER index ((Land Equivalent Ratio) has been studied by many researchers. The conclusion that can be draw, when the index standardized by unique divisors in the same analysis, the precision of the analysis of variance is satisfactory. This result was expected, since, with those standardizations, the used indices are only simple sums of random variables, and in these cases, the distribution is know. The problem that arises, according to Oyejola & Mead (1989), is that the divisors even being constant in the same analysis, they are random variables, and their variability, must be considered. In the present work, the precision of the LER index analysis of variance, using computer simulated data was studied. LER index was standardized by the yield mean of the single crop, when a correction of the standard derivation was made, according to Oyejola & Mead (1989), with the objective to consider these variabilities.

§    KEYWORDS: Analysis of variance precision; correction of the standard error; index; intercropping.

 

 



[1] Pesquisador do CNPq - Departamento de Ciências Exatas da Faculdade de Ciências Agrárias e Veterinárias - UNESP- 14870-000 - Jaboticabal - SP .