It is recommended to seek out the guidance of experts who have experience for installation of your irrigation system. Landscape contractors typically have the experience and knowledge necessary to identify the issue and correct it. A dripper could be put in the supply line for regulating the flow of water. To determine if the quality of the supply is satisfactory, a pressure gauge may be utilized to test the pressure. It could be that the issue is lower down at the connector point. If this is the case, then the pressure should also be examined. If the pressure is low, there is an insufficient amount of water circulating through the line, causing that the plants receive lower amounts of water. Consider dividing your system into two sections with separate lines to reduce the length of the line, and test if the irrigation system functions better. Test this hypothesis to see if it works by turning off the water and checking the results on the gauge again. Contact an irrigation service company within the region you reside in. su41g19s7h.