Effects of Forchlorofenuron (CPPU) treatment on fruit properties in the fruit of common guava

The common guava is a small tree from Myrtacaeae family which is cultivated for its fruits. Researches have explored new methods to promote fruit yields and quality of crops. Application of Forchlorofenuron or CPPU (with Molecular Formula: C12H10CIN3O) improves the fruit size as well as its quality, but there has not been an investigation evaluating its effects on common guava fruit under field conditions. This research was performed to study the effects of different doses of CPPU (0, 10, 20 and 40 mg L-1) on common guava fruit size and quality characteristics under field conditions. Analysis of variance and LSD (least significant differences) mean compression indicated that total soluble solids, total acidity, ascorbic acid or vitamin C, fruit firmness, phenolics, 1,1-Diphenyl-2-picrylhydrazyl (DPPH), polygalacturonase, pectin methyl esterase and ethylene were significantly different in most traits and CPPU-40 produced high means. The principal components (PC) analysis explained 95% of the total variation and the first two principal components (PC1 and PC2) explained 78% and 17% of the total variation, respectively. According to biplot, CPPU-40 had the highest values for all of the measured traits except DPPH, ethylene and polygalacturonase. The most prominent relations by biplot were a strong positive correlation among phenolics, fruit firmness, total acidity, total soluble solids and ascorbic acid as indicated by the small obtuse angles between their vectors. The measured traits were grouped into two clusters and cutoff point verified via Wilks’ lambda statistics. Cluster I consisted of three traits (ascorbic acid or vitamin C, fruit firmness and ethylene) while cluster II included total soluble solids. Findings of this study suggest that CPPU can be used as an effective growth regulator to improve the size and quality of common guava fruit.