SEPARATING PHOTOPERIOD AND TEMPERATURE EFFECTS ON THE DEGREE DAY REQUIREMENT FOR FLORAL EVENTS IN SOYBEAN

A control for moving a pallet relative to first and second base plates including four carriages that are rotatably supported on the second base plate by second rollers and which can be moved by pistons that are mounted in cylinders that are attached to the second base plate. The first plate has downwardly extending members formed with slanted slots and each of the four carriages have first rollers received in the slots so that as the pistons are moved in the cylinders the first base plate and the pallet are raised and lowered relative to the second base plate. Third rollers are mounted between the pallet and the first base plate so that they are movable relative to each other.