Seed treatment and sowing depth on emergence and growth of the signalgrass

Abstract

The success in the pasture formation is dependent on factors such as soil fertility, quality of seed, seed treatment for pests and control of diseases and proper seeding. This study aimed to assess the seed treatment, emergence seeding depth on the growth of signalgrass (Urochloa decumbens Stapf). Thus, two experiments were conducted, one in greenhouse and another one in the field. In the first one, we assessed three seeding depths of signalgrass (0, 3 and 6 cm) and three seed treatments (thiamethoxan, fipronil and control). In the second trial we assessed two methods of seeding of signalgrass (in the furrow, and broadcast sowing) and three insecticides for seed treatments (thiamethoxan, fipronil and control). In the greenhouse, the seeding at 6 cm depth decreased by about 90% the plants density, dry mass of stems, leaves and roots. Greater plants emergence was observed in the 0 and 3 cm depth, without effect of the insecticide treatment. Under field conditions the insecticide application did not affect the emergence and growth of grass when sowing was carried out in the furrow, but broadcasting seeds at planting significantly increased plant density and dry weight of shoots. It was concluded, for U. decumbens the sowing depth of 6 cm should be avoided and the use of insecticides thiamethoxan and fipronil improves the establishment and growth of forage, mainly in broadcast sowing.