Figure 4From: Improving Water Use Efficiency of Lettuce (Lactuca sativa L.) Using Phosphorous Fertilizers Photosynthetic active radiation (PAR) measured inside the greenhouse during three selected days of three months (7 Febraury, 31 March and 9 April 2010) during the growing season 2009/2010 at The Jubeiha Agricultural Research Station of the University of Jordan. Back to article page