Time and duration of weed interference on yield and growth characteristics of the potato furrow and drip irrigation methods

A field experiment was conducted in research farm of Isfahan University of technology، Isfahan، Iran in 2011. Various weeding periods were investigated on growth and yield of potato under drip tape and furrow irrigation systems. A split plot arrangement was used in a randomized complete block design with three replications. Irrigation treatments were included in main plots and periods of weed control in sub plots. Weed treatments included two series of periods of weed free and weed interference at intervals of 20، 30، 40، 50 and 60 days after emergence. Two treatments of weed free and weed interference applied over the entire growing period were also considered as control treatments. The period of weed interference had significant effects on weed density. Overall، weed density was higher under drip compared to furrow irrigation. The highest weed density was observed at early stage of growing period under both irrigation systems. Howevere، during the later stages weed density was reduced، due to self-weeding but weed dry weight was increased. Results also showed that weed interference led to significant losses in plant height، latteral stems، stem number، and leaf dry matter and the yield of potato plants.