RELATIONSHIP BETWEEN SEED SIZE AND DEPTH SOWING WITH THE VIGOR OF SEEDINGS IN ALFALFA

Abstract

Rapid seedling establishment is an important attribute for a successful crop production. In order to know the relationship among seed size, seed vigour, and sowing depth, in 1988 a study was carried out using five varieties of alfalfa Medicago saliva L. (INIA 76, Puebla 76, San Joaquín 11, Aragón and Moapa 69). A combination of three seed sizes (large, medium and small) and three sowing depths (1, 2 and 3 cm) was used under laboratory and greenhouse conditions. A randomized complete block and split-split-plot designs, with four replications in each case, was respectively used. Under laboratory conditions, it was found that the medium and small seed sizes had 12 to 16% more germination for INIA 76, and Puebla 76, while the other varieties only had 6% more. The large seed size of all varieties showed good seedling vigor in both conditions, and the dry matter production was al so higher. Under greenhouse conditions, more emergence was found at the small depth, particularly Moapa 69 (60%) and Puebla 76 (277%), and this behavior was similar to laboratory condition. Varietal differences were found in seedling vigor and seed size, so selection for these characters could be practiced in species with small seed size to increase seedling establishment.