The John Deere electronic thinner, after proper adjustment, performed

satisfactorily. Certain precautions are imperative. The planting operation

should leave a flat or nearly flat surface as ridges and depressions interfere

with thinner performance. lWhen the planter leaves a shallow furrow (which it

usually does) rolling the ground is necessary to leave the ground level and

compacted. Shallow flat planting of the seed about 1 inch deep facilitates

emergence and improves uniformity but at the same time facilitates lodging if

the soil is not properly accumulated around the plants after thinning. Best

plant spacing for thinning appears to be 2 to 3 inches. Near perfect weed control

is very necessary since the sensing mechanism cannot distinguish between weeds

and corn plants. Four pounds per acre of Vegadex plus 2 pounds of Randox gave

the desired weed control. The corn plants should be no taller than 6 inches and

no less than 2 inches. Probe and knife height adjustment are critical. It is

necessary that the operator maintain the thinner in proper row alignment and

that he check frequently for malfunctions. His task is simplified if the

thinner is front mounted.


 Acknowledgment

 The authors would like to thank the Everglades Farm Equipment Company,

 Belle Glade, for the loan of the tractors and plateless planters; the Glades

 Equipment Company, Belle Glade, for the loan of the tractor and cyclone seeder;

 and the S. N. Knight Farm for the loan of the electronic thinners without

 whose help these studies would not have been possible.





 EV-1972-6
 450 Copies