Overcoming Tegumentary Numbness in Seeds of Crotalaria spectabilis and Crotalaria paulinea

Abstract

Objective: To evaluate the efficiency of dormancy breaking methods in seeds of C. paulinea and C. Spectabilis.
 
 Theoretical reference: Species of crotalaria, such as C. paulinea and C. spectabilis, found in the Brazilian territory, are used as green manure in large crops and vegetable productions. However, the presence of tegumentary hardness in their seeds can result in failures in soil cover, which favor the emergence of weeds.
 
 Method/design/approach: The research was carried out at the Laboratório de Análise de Sementes of the Departamento de Agronomia, at the Universidade Federal de Viçosa, Minas Gerais. Twenty treatments were applied to the seeds to break dormancy, using mechanical scarification with 120 grit sandpaper, hot water in an oven at 90 °C for five and seven minutes, and immersion in sodium hypochlorite at four concentrations, 2%, 4%, 6% and 8%, for four times, two, four, six and eight hours.
 
 Results and conclusion: The most efficient treatments for breaking this dormancy in both species of crotalaria were scarification with sandpaper and immersion in water at 90±3 °C for seven minutes. Treatments using sodium hypochlorite were not effective in reducing the number of hard seeds.
 
 Originality/value: Feasibility of the methods applied to break dormancy in seeds of C. paulinea and C. Spectabilis, since they are used for green manure, and control of Aedes aegypti, among other purposes.