Effect of water stress, biofertilizers and nitrogen application rates on cowpea yield and some water relations in the north middle nile delta region [electronic resources].

Includes reference.

Two field experiments were carried out at Sakha Agricultural Research station (31°o5' N latitude and 30°57' E longitude) Kafr El-Sheikh governorate during the two successive summer growing seasons 2012 and 2013 to investigate the effect of water stress through various growth stages, biofertilizers and nitrogen application rates on cowpea yield, its components, uptake of phosphorus, nitrogen and protein content in some plant organs and some water relations in the North Middle Nile Delta region. A split split plot design with four replicates was used in this present study where the main treatments were randomly assigned by irrigation treatments which were I₁, (control treatment), I₂ (withholding one irrigation at the vegetative growth stage), I₃ (withholding one irrigation at the flowering growth stage) and I₄ (withholding one irrigation at pod formation stage), where the sub-plot were randomly assigned by application of nitrogen which were three rates of application, N₁ (control treatment, without nitrogen application), N₂ (application of 15 kg N/fed.) and Na (application of 30 kg N/fed. which considers the recommended dose for cowpea). where the sub sub plot were randomly assigned by biofertilizers which were b₁ (without biofertilizers application) and b₂ (application of biofertilizers for the soil after emergence), The main results of this present investigation can be summarized as follows: amount of seasonal water applied were clearly affected by irrigation treatments. The highest values were recorded under irrigation treatment I₁ comparing with other irrigation treatments I₂, I₃ and I₄ in the two growing seasons. The highest values were 2950 m³/fed. (70.2 cm) and 2980 m³/fed (70.95 cm) in the first and second growing seasons, respectively.

Summary in Arabic.

1