Early harvest data compares John Deere S770 and S780 performance

A South Texas custom harvesting crew is comparing early-season performance data between John Deere S770 and S780 combines as wheat harvest progresses across the region.

Operators said difficult harvest conditions, high humidity and uneven wheat yields have limited opportunities to fully evaluate combine performance during the first days of harvest.

The crew reported that persistent moisture delayed harvest starts until late afternoon on several days. In some fields, wheat moisture ranged from 12.5% to more than 22%, depending on crop maturity and field conditions.

Harvesters also faced trucking shortages that temporarily slowed operations. Some grain was stored locally while crews waited for trucks to haul wheat to elevators.

During harvest, operators tracked acres harvested per hour, fuel consumption and fuel use per acre between the two combine models. Early results showed the S770 averaging 18.4 acres per hour while using about 16 gallons of fuel per hour. Fuel use averaged approximately 0.9 gallons per acre.

The S780 averaged 19.1 acres per hour while consuming about 20.6 gallons per hour, or roughly 1 gallon per acre.

Operators noted the S780 used nearly 29% more fuel per hour while producing about 3.8% more productivity under current field conditions.

The crew said the S780 likely requires a larger header to fully utilize available horsepower in lower-yielding wheat conditions. Current wheat yields in some fields averaged roughly 33 bushels per acre.

However, operators said larger headers could complicate logistics for grain carts and harvest efficiency when running multiple combine models together.

Crews emphasized the data remains preliminary because harvest conditions have included short cutting windows, lodged wheat, weed pressure and repeated weather delays.

Operators said they plan to continue monitoring combine efficiency throughout the harvest season as conditions change across different wheat-producing regions.