Calcium foliar sprinkling and its relation with fruit quality of mangoes cv. Haden.
Romero-Gomezcaña N. R., Sánchez-García P., Rodríguez-Alcázar J., Saucedo-Veloz C.
Author Affiliation: Programa de Fruticultura, Instituto de Recursos Genéticos y Productividad Colegio de Postgraduados, Km 35.5 carretera México-Texcoco, 56230 Montecillo, Texcoco, Estado de México, Mexico.
Agricultura Técnica en México 32 : 5-15
Abstract : The aim of this research was to determine the effect of calcium foliar sprinkling and its relationship with other nutrients on fruit quality of mangoes cv. Haden. An experiment was conducted on 16-year old trees during 2003 at San Lucas, Michoacan, Mexico (18°19? north latitude, 100°40? west longitude and 251 masl). Treatments consisted of five concentrations of Ca(NO3)2 (, 5, 10, 15 and 20 g L-1), five foliar sprays of each were made every 15 days in pre-harvest. A completely random design with four replicates was utilized; each experimental unit consisted of three trees. Ca treated trees had significantly higher fruit yield than the control. Fruits kept at 20±2°C and 74±4% R.H. showed significant differences (p?0.05) in respiration, fruit weight loss, acidity, and total soluble solids, but not for fruit firmness and colour, as well as for pectin-metylesterase activity. Fruit firmness correlated positively with the K/Ca ratio (r=0.9571**) and with pectin-metylesterase activity (r=0.6844**). Likewise, regression analysis of fruit firmness with K/Ca and K+Mg/Ca ratios were significant (p?0.05) with R2 of 0.9160 and 0.8504, respectively. Furthermore, regression analysis between °Brix/Acidity and Ca2+ rates was significant with a R2 of 0.82 (p?0.05). Also, the analysis of °Brix/Acidity with K/Ca and K+Mg/Ca, resulted significant (p?0.05) with R2 values of 0.82 and 0.86, respectively, and not for the N/Ca ratio. Fruit firmness had a positive relationship with K/Ca and with pectin-metylesterase activity. With the increases in the K/Ca and K+Mg/Ca ratios, fruit firmness also increased.