The effect of different phosphorous fertilizer on yield and yield components of corn (Zea mays L.) under with and without pigweed (Amaranths retroflexus)

Subject Areas : Journal of Plant Ecophysiology

سیروس  منصوری فر ¹ (دانشکده کشاورزی دانشگاه پیام نور)
مسعود  کرکه آبادی ² (دانشکده کشاورزی دانشگاه پیام نور)
A.  Fallah ³ (دانشکده کشاورزی، دانشگاه پیام نور کرج)

Received: 2014-07-01 Accepted : 2014-12-27 Published : 2015-10-01

Keywords: Nutrient, Yield, Weeds, Competition,

Abstract :

In this research grain yield and yield components of corn were examined under competition with pigweed on P in a factorial experiment based on completely randomized design (CRD) with four replicates. The treatments included planting methods: pure corn, corn /pigweed intercropping and pure pigweed; and P amount in five levels: 0 (as control), 80, 160, 240 and 320 kg ha-1 as triple superphosphate resource. The results showed that P fertilization as 320 kg ha-1 increased grain number in ear (41.6%), thousand grain weight (19.2%), grain yield (33.4%) and biological yield (31.8%) of corn, as well as, plant height (27.0%) and dry weight (34.3%) of pigweed in pure culture. However, thousand grain weight of corn in the last P level (320 kg ha-1) and plant height and dry weight of pigweed in last two levels of P (240 and 320 kg ha-1) in intercropping were reduced. Intercropping of pigweed had negative effect on yield and yield components of corn, especially in lower P levels; while there is no significant effect in highest P level. This means that P had positive effect on competitiveness of corn against pigweed. Overall, for achieving to greater competition ability of corn against weeds such as pigweed and lower cost, 240 kg ha-1 P fertilizer can be recommended for future investigations.