Pump Vs. Water Valve Timer

Okay so if you haven't heard, we have a problem in Hermann, Mo with the drip irrigation system.  The pump being used creates a siphoning effect after it turns off and will continue to water.  We have all seen the pictures of the setup.  The water barrel is above the hops on a small hill collecting rain water.  Do you have any suggestions on how to fix this?

I have been doing some searching and this is what I have come up with it.  Please look it over, and let me know if you guys find anything about it that could be a snag in the plan.  I suggest we just use gravity, and get rid of the pump and use this for $24  at Home Depot.  Picture below:

Here is the description from the site:

The best time to water is right at sun up to prevent disease. Do you want to get up at 5 AM to water everyday? This timer allows you to set the time you want to water, up to 3 times a day and up to 2 hours each time. Never over water again, simply set and forget. Program to automatically start and shut off. Works with low pressure drip and soaker hoses. Set to water while you are away or at night. On/off to use like a faucet.

• Never over water again, simply set and forget
• Program to automatically start and shut off
• Works with low pressure drip and soaker hoses
• Set to water while you are away or at night
• MFG Model # : 3015V
• MFG Part # : 3015V

Let me know what you guys think.  We can't have these hops drying out.  We need a plan ASAP!