Multivariate diagnosis of nutrient imbalance in rose grown under open and protected conditions using compositional nutrient diagnosis and principal component analysis

Abstract

A data bank of nutrient concentration VS yield was developed for rose grown under open and protected conditions through a survey to develop multivariate nutrient diagnostic norms using compositional nutrient diagnosis. Three hundred and twenty leaf samples were collected when flower buds were of pea size and were analyzed for different nutrients. The compositional nutrient diagnostic norms for identification of yield-limiting nutrients were developed. Although, the mean nutrient concentrations in leaves between open and protected conditions showed marginal difference, the compositional nutrient diagnosis norm values differed with higher diagnostic sensitivity. The interaction among different nutrients was explained by principal component analysis on log-transformed data. The principal component analysis extracted 4 significant principal components under protected conditions namely (N+P+Fe- Zn-), (Ca- S+), (K+ Mn-) and (P- Mg+), which explained nearly 70.30% of variance, while only 2 significant principal component, viz (N+P+Ca-Mg- S+Fe-Mn-Zn+) and (K+Ca+Mg+Fe-Zn-) were formed under open conditions explaining nearly 74.26% of variance. The principal component analysis indicated that K had an overwhelming interaction with Ca and Mg. The multivariate technique revealed greater imbalance of Fe and Zn, followed by K under protected conditions and Ca, Mg, Fe and Zn under open conditions. Thus, the multi-nutrient interactions need to be understood for proper management of nutrients to sustain yield and quality of cut flowers in rose.