Trademarks are limited to the trades (i.e. 'goods& services') listed in the trademark application. Apple, Inc doesn't sell apples. Nor do they have apple farms. Visit USPTO's TESS and search for serial number 87628828. The "Goods and Services" field contains no mention of fruit, farms, or produce.

You must diligently protect your trademark against uses by others in similar markets. I would hope that protecting your computing business against apple farmers would get you, at a minimum, a frown and a "no" from a judge or the enforcing agency.