SOME PHYSIOLOGICAL CHARACTERISTICS OF THREE PINEAPPLE CULTIVARS GROWN UNDER TWO DIFFERENT PRODUCTION SYSTEMS

Abstract

‘Cayena’ Lisa is the pineapple cultivar most widely used in Mexico. However, the study of other cultivars before introducing them into our country is imperative. In this study some features related to drought resistance were determined under two growth conditions: plastic mulch and bare soil. In each treatment the cultivars ‘Cayena Lisa’, ‘Champaka’ and ‘Oro’ were evaluated under a randomized block design with four replicates, in split plot. Samples were collected in the dry season, at the beginning of the rainy season, just before floral induction and during flowering. The results showed that the pineapple cultivars behaved as a typical CAM plant. In the early development stage and during blooming, CO2 fixation was similar in plastic mulch and bare soil treatments; however, at floral induction, the plastic mulch treatment had higher values. In the early development stage cv. Oro was more efficient in the CO2 fixation, but this happened only in the early morning. There was also an inverse relationship between pH and malic acid content. During the dry season, RWC (relative water content) was lower in bare soil than in the plastic mulch treatment. RWC values obtained for ‘Cayena Lisa’ and ‘Champaka’ were higher than those obtained for cv. Oro. The cv. Oro had the higher chlorophyll content and the fewer stomata, but larger in size, than in the other cultivars.