Geopedological transects in karst landscapes in Campeche, Mexico

Resumen

Objective: Apples cultivated in Mexico generally are smaller and softer than those produced in other geographical latitudes considered as optimal for apple production. The aim of this evaluation was determine the effect of applications with calcium, nitrogen, potassium, magnesium, sulfur and naphthaleneacetic acid (NAA), as well as the harvest date on the quality of apple fruits. Methodology ‘Golden Smoothie’ apple trees were treated foliarly with CaCl2 with and without NAA, and with a mixture of N, K, Mg and S or gypsum applied to soil for two years. Apples were harvested at 141 (regular harvest date), 161 (mid-late harvest) and 171 days (late harvest) after full bloom (DAFB) and evaluated for quality at harvest time and during their storage at 0°C for up to 179 days. Results: Foliar applications of CaCl2 significantly increased the calcium content in fruit and leaves, but fruit quality, including firmness, was not influenced. Fertilization of soil with the mixture of nutrients, including CaSO4, did not influence the fruit quality. Lately harvested fruit was 14.9% heavier but 17.1% softer than fruit picked at the commercial harvest date. Delaying of fruit harvest reduced about 43 d the storability of fruit. Based in these results, the relative softness of apples grown in Mexico is not related with its calcium content, hence unlikely to be overcome with the application of this mineral. Conclusions: Even in the control fruits, both seasons, the stored fruits do not show some physiological disorder as bitter pit