Effect of Crop Age on Seed Yield of Arachis pintoi at Two Sites in Costa Rica

Arachis pintoi is a forage legume well adapted to the humid tropics of Costa Rica. Seed production studies were carried out at two contrasting localities within the country, Gulipiles (very humid tropics) and San Isidro (seasonal evergreen tropical forest). The accessions CIAT 18748, 18744 and 17434 cv. Amarillo of A. pinloi were vegetatively planted at both sites. Seed yields were measured at 8, 12, 16 and 20 months post- planting inGulipiles, and at·8, 16 and 20 months in San Isidro. Mean seed yields among accessions were similar in San Isidro but significantly different in Gulipiles; however, the contrary occurred in relation to date of harvest. At San Isidro the 16th-month harvest produced the higher seed yield for all accessions (mean of 1229 kg/ha). CIAT 17434 was the more prolific accession in Gulipiles with nearly 1 t/ha of seed, while CIAT 18744 had the lowest seed yield, but larger pods and more lop growth.