Estimates of leaf area index and net assimilation rate for celery. [Spanish]Original Title Estimados de indice de area foliar y razon de asimilacion neta para apio.

摘要

Leaf area index and net assimilation rate were estimated for celery grown under ambient conditions on Humata soil series (Typic Haplohumults) in Barranquitas, Puerto Rico. Plants were sampled from Quebradillas, sector Farallon (elevation of 787 m, with a soil pH of 4.2), and Palo Kneeling, sector La Torre (elevation of 826 m, with a soil pH of 5.8), both established in 1996, as well as from Quebradillas, sector La Ermita (elevation of 760 m, with a pH of 4.3), which was established in August 1997. At 40 days after planting (DAP), N fertilizer was applied at rates ranging from 0 to 150 kg/ha (interval of 25 kg/ha). The N rate had no significant effect on plant growth. The leaf area index and net assimilation ratio were calculated based on dry weight and leaf area. In Farallon, total dry weight and corm dry weight increased significantly up to 146 DAP, then decreased. The dry weights of petioles and leaf blades were highest at 118 DAP, significantly decreasing later in the crop cycle. In La Torre, the dry weights of plant parts increased throughout the crop cycle, except for the leaf blade. In this locality, the plants exhibited greater dry matter accumulation per unit time, and on average were more developed than those in the other two sites. In La Ermita, the plant dry weight increased throughout the growing season, although the dry matter weight did not reach the standard for cash crops.