Evaluation of crisphead lettuce cultivars in different cover types by manova and discriminant analysis

Horticultura Brasileira

Izabela Regina C De Oliveira²  Marcelo T Rezende¹  Carlos Tadeu Dos S Dias²  Daniela De S Gomes¹  Élberis P Botrel¹  Luiz Antônio A Gomes¹ 

[1] ,Universidade de São Paulo ESALQ Piracicaba SP ,Brazil

关键词: Lactuca sativa;    cover crop;    multivariate analysis;    organic production;    Lactuca sativa;    cobertura vegetal;    análise multivariada;    produção orgânica;   

DOI  :  10.1590/S0102-05362013000300015

来源: SciELO

【 摘 要 】

In many agricultural experiments the variables are biologically correlated and it is inappropriate to study them only under univariate analysis. Therefore, we evaluated commercial characteristics of crisphead lettuce cultivars and covers under a multivariate approach, using canonical discriminant analysis. We used a split plot design and we tested the cover crop, cultivar and interaction effects by using MANOVA (α= 5%). Means and its standard errors were obtained for average total weight, weight of the head, volume and density of plants. Canonical discriminant analyses were performed using PROC CANDISC procedure in SAS (SAS Institute, 2008) system. Canonical plots were obtained using JMP 9.0 (SAS Institute, 2010) linked to SAS database. With these plots it was possible to note the differences among factors levels. When polyethylene film was used as cover the plants had inferior commercial characteristics than plants in which cover crops were used. Thus, the cover with polyethylene film can be discouraged in the cultivation of crisphead lettuce, promoting environmental sustainability. We suggest these multivariate techniques in horticulture studies.

【 授权许可】

CC BY   
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