Emergence and Initial Development of Amaranth (Amaranthus cruentus L.) BRS Alegria at Different Depths of Seeding and Water Availability

The depth of seeding and the availability of water influence the seed germination process. Amaranth has small seeds from 1.0 to 1.5 mm and limited nutrient reserves and, after emergence, slow growth. Thus, the objective of this work was to evaluate the emergence and formation of amaranth seedlings. The experiment was carried out in a vegetation house at the Federal University of Mato Grosso - Brazil, between October and November 2018. The factor "A" refers to two seeding depths (10 and 20 mm) and the factor "B" to four of water availability (100%, 80%, 60% and 40% of retention capacity). The emergency, first count and emergency speed index were evaluated. Height, diameter, root length, number of leaves, mass of fresh and dry matter were also evaluated. The emergence of the seedlings, independently of the seeding depth, was greater in water availability of 100 and 80%. There was interaction of factors for the first count and emergency velocity index. The first emergency count was higher in water availability of 100%. At a seeding depth of 10 mm, the first count of emerging seedlings was similar in water availability of 100, 80 and 40%. While, at a depth of 20 mm, the first count was higher at water availability of 60%. The emergency speed index was higher for 100% water availability at 10 mm seeding depth, while at 20 mm depth the water availability had no effect on the emergency speed index. The water availability of 60 and 40% of the retention capacity reduces the height of the plant, the diameter of the stem, the length of the root, the number of leaves, the mass of fresh and dry matter. Increased seeding depth reduces height, number of leaves and production of fresh and dry amaranth matter.