Weeds'| seed transported by the irrigation water. IV. Contamination with weeds along an irrigation canal

Raúl Ferreyra E.1,Juan Tosso T.1 y Leonardo Muñoz S.2

Ouring the season 1982/83, a study was conducted in arder to quantify the weed seeds transported by the water of an irrigation canal system. Samples were taken every 15 days, in five different points along the system, in the Santiago Val ley. Results indicated that the irrigation water carries a large amount of weed seeds, that varies according to the sampling period and place of sampling. The number of seeds found varied from 147 to 10.024/1.000 m3; as the distance from the intake of the canal at the river increased, the amount of weed seeds ih the irrigation water was higher. Also, the larger amount was measured between January and March. With the data obtained, it was estimated that the irrigation water deposits about 64.000 weed seeds on an hectare of deciduous orchard and about 40.000 on one hectare seeded with a bean crap.

1 Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.
2 a/c de Raúl Ferreyra E., Casilla 439, Correo 3, Santiago, Chile.