The influence of different types of perennial mulch on the weed seed bank in an orchard

Mulching is an agrotechnical measure often used in orchards and it means covering the soil with the organic or inorganic material in order to prevent the germination of the weeds. The other positive effects imply: the improvement of the physical and chemical soil characteristics, decrease of soil erosion and water loss, the prevention of the soil crusting, etc. The research of the weed seed bank under the different types of mulch was conducted during the growing season of 2021. in a plum orchard located at Rimski Šančevi. The black and white agrotextile and white mulch film, unlike the other mulches, left the surfaces clean, without the weeds. The analysis of the weed seed bank revealed the seeds of 20 weed species, of which 12 were not found to be present in the orchard during the experimental year. The overall germination rate of the obtained weed seeds is low because in the three-year experiment with mulches, there was no influx of new weed seeds for several years, while the old ones lost their germination. The highest germination percentage was noted for the seeds of the following species: Amaranthus retroflexus, Stellaria media and Solanum nigrum, due to their ability to retain germination for a long period of time. The highest number of the seeds per m2 was found in the inter-row space due to the large influx of the seeds during the growing season. The highest germination rate was observed in case of the seeds found under the sawdust mulch. None of the ungerminated seeds showed the viability, as determined by the Crush test.