John Deere's 7760 cotton picker with on-board module builder had a slightly higher efficiency and picking capacity than its Case IH ME 625 counterpart and conventional picking systems, according to a study by agricultural engineers. The study also showed that operators of the Case IH 625 model had the potential to significantly improve efficiency and capacity, more so than operators of the Deere model.

The study, in which researchers rode in pickers for 12 or more hours a day for a month last fall, was not designed to determine the economics of one picking method over another.

Data was collected in four states in 2008 on 10 farms and 28 fields in 29 days of picking. The researchers rode in the jump seats of the pickers with a laptop computer and an external GPS receiver. The study was funded by Cotton Incorporated.

According to University of Tennessee agricultural engineer Michael Buschermohle, the Deere model demonstrated higher field efficiency and picking capacity primarily because of its reduced unloading time. Downtime was also included in the study.

The average time to unload cotton in a conventional-type picker was 2.6 minutes. “If the driver is on the row when his basket is getting full, he called for the boll buggy, unloaded the basket and continued picking. That's the most efficient way of unloading a conventional picker.”

The average time to unload for the Case IH 625, varied quite a bit, according to the research. The shortest time to unload was about 1 minute and 22 seconds and the longest time was close to 5 minutes. The average time was about 2 minutes and 30 seconds.

The John Deere 7760 picker basically took no time to unload its module. “When the operator completed the round module, most of the operators put the module on the cradle and carried it with them until they got to the end of the row and dumped it. Some unloaded in the stalks and others unloaded in field roads at the end of the row.”

However, the John Deere model did require additional time to change the roll of wrap used to protect the round modules. Researchers decided to apply that time as unloading time.

Average time to change the roll ranged from 3.6 minutes to 9.5 minutes with an average of 6.7 minutes. At 22 wraps per roll per round module, it came out to about 18 seconds for each unloading.

Average load size for the John Deere round bale was about 3.74 bales per module, compared to 6.5 bales for the Case IH and 17.8 bales for a conventional module. That comes out to 1,795 pounds of lint per unload for the round module, 3,125 pounds for the Case IH half module and 3,200 pounds for the conventional picker (2.67 dumps are required per conventional module).

The researchers also applied the data they gathered to simulate how the pickers might have performed in different fields. For example, when harvesting at the advertised first gear picking speed on a 13-acre, triangular-shaped field with a 992-pound yield, the simulation model predicted that the Case IH (4 miles per hour) would harvest 6.5 acres per hour at 70 percent efficiency; the John Deere (4.2 miles per hour) would harvest 7.2 acres per hour at 75 percent efficiency while the conventional pickers running at 4 and 3.6 miles per hour would harvest 6.4 acres per hour at 70 percent efficiency and 5.9 acres per hour at 72 percent efficiency, respectively.

On a 50-acre field with a 992-pound yield, the model projected a field efficiency of 76 percent, 82 percent,76 percent and 77 percent, respectively, for the Case IH, John Deere and conventional systems operating in first gear. The computer projected a field capacity of 7 acres per hour, 7.9 acres per hour, 7 acres per hour and 6.4 acres per hour, respectively, for the Case IH, John Deere and two conventional systems.

Buschermohle noted that Case IH 625 operators can have more of an impact on improving unloading time than John Deere operators. This was observed in cases where simulations for a field could be compared with what actually occurred in the field.

For example, according to a simulation, a Case IH picking in second gear (4.8 miles per hour) in an 84-acre field with a yield of 1,200 pounds, would have 31.6 unloads and a total unload time of almost 75 minutes, “which would give you a predicted field capacity of about 8.1 acres per hour and an average unload time of 2.3 minutes.”

However, in the actual operation, the Case IH operator averaged only 4.5 miles per hour. “He ended up with 35 unloads in the field and his total unload time was tremendously lower than what we would have predicted. He was able to come out of the field, unload a Case IH half module and get back in the field in 1 minute and 22 seconds minutes and he did that consistently for 35 unloads.”

The operator of the Case IH had a field efficiency of 78 percent, compared to a prediction of 73 percent. His actual total unload time was around 48 minutes compared to a prediction of 75 minutes. “So the operator can make a tremendous difference on the Case IH, much more so than on the Deere.”

The researchers also found that fluctuations in field efficiency as a function of yield were less in the John Deere model. “For the Case IH and conventional pickers, we saw a 7 percent to 8 percent drop in efficiency going from a 1 bale to 3 bale yield, compared to 1 percent to 2 percent for the John Deere.”

Buschermohle stressed that the study was not an economic analysis. “There are many other factors that need to be considered including the costs of the picker, the labor, labor availability, fuel consumption, available farm machinery, wrap versus tarp costs, ginning costs, ginning rates, hauling costs and lint and seed quality.”

Economists at MSU have developed a model that integrates these economic factors. On the 50-acre field with a 992-pound yield, the model predicts the picking to ginning cost at about $100 per acre for the 3.7 mile-per-hour conventional picker. Expenses included typical picking costs as well as costs for module building, tarps, hauling to the gin and ginning costs. The John Deere 7760 was predicted at about $7 more per acre and the Case IH, $9 less. Scientists conducting the study stressed that economics may vary from farm to farm.