Effects of polyethylene film mulching on contents of NO3-N in soil, growth and immature fruit yield of Okra(Hibiscus esculentus L.)

analyse statistique caracteres de rendimiento composante de rendement crecimiento croissance crop yield cubrimiento del suelo film plastique growth hibiscus esculentus mulching nitrogen content paillage plastic film rendement des cultures rendimiento de cultivos soil temperature statistical analysis temperatura del suelo teneur en azote yield components