Document Type : Research Paper
Open Univ. of Cyprus, Nicossia. Cyprus.
School of Biological Sciences, University of Reading, P.O. Box. 217, READING, Berksire, RG6 6AH, United Kingdom.
Laboratory of Agronomy, School of Agriculture, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
Laboratory of Weed Management. Univ. of Thessaly. Volos, Greece.
Laboratory of Crop Production, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
Field experiments were conducted to determine the effects of organic and
inorganic amendments on weed suppression in sweet maize cultivation (Zea mays
L.). A randomized complete block design was employed with four replicates per
treatment with each organic amendment used at half (x/2), single (x=10 t ha-1) and
double (2x) rates (organic fertilization: cow manure, poultry manure and barley
mulch; synthetic fertilizer (240 kg N ha-1: 21-0-0); and control). The highest
number and dry weight of weeds were recorded for double cow manure and
chemical fertilizer treatments. The cow manure treatments promoted weed
emergence and growth proportionally to the rate of application (x/2<x<2x). In the
presence of barley residues, weed biomass or density was reduced for the species:
redroot pigweed (Amaranthus retroflexus L.), common purslane (Portulaca
oleracea L.) and prostrate knotweed (Polygonum aviculare L.). Weed suppressive
effect of barley residues decreased with time following residue decomposition. The
barley mulch plots presented the highest values of Shannon-Weiner and Simpson
indices. These results indicate that green manure of barley are effective for the
suppression of some weeds in sweet maize.