Drones that monitor crops, control mosquito populations and deliver defibrillators are to be tested in US airspace.

Ten commercial drone projects have been selected to try out new ways for unmanned aircraft to be integrated into the skies.

They include Zipline, which currently offers a blood-delivery service in Rwanda, and Apple.

But Amazon, which wants to offer drone parcel deliveries, has not been chosen.

The Federal Aviation Authority has previously had extremely tight rules about the use of drones.

A permit is needed to fly one, with beyond line-of-sight flights and night-time flying banned.

More than one million drones and 90,000 pilots are currently registered with the FAA.

The UAS (Unmanned Aircraft Systems) Integration Pilot Program is designed to tackle some of the challenges of integrating drones into national airspace, particularly how to reduce risks to public safety.

No Amazon

Phone maker Apple was among those chosen and will capture images of North Carolina by drone, while Microsoft, Uber and Intel will all be involved in projects.

According to Reuters, Amazon applied to deliver goods by drone to shoppers in New York but was rejected. Similarly it said that DJI, the world's biggest non-military drone maker, made about a dozen applications but had none approved.

The 10 chosen projects include:

• A government agency in Florida will use drones to help control mosquito populations
• The Choctaw Nation of Oklahoma will work on flying drones beyond a pilot's line of sight, in partnership with CNN
• North Carolina will work with Flytrex to test food delivery services
• FedEx will work with Memphis County Airport Authority using drones for security and infrastructure and to deliver parts
• The City of Reno in Nevada will work with Flirtey on delivering medical supplies

The 10 winners were picked from 149 proposals. Full details of each trial have not yet been released but each applicant will have around two-and-a-half years to run the trials, sharing information with the FAA along the way.

"Data gathered from these pilot projects will form the basis of a new regulatory framework to safely integrate drones into our national airspace," said US secretary of transportation, Elaine Chao.