Crop improvement

In industrialized agriculture, crop "improvement" has often concentrated nutritional and other qualities of food plants to serve the interests of producers. After mechanical tomato-harvesters were developed in the early 1960s, agricultural scientists bred tomatoes that were harder and less nourishing. In fact, a most important longitudinal study of nutrient levels in several vegetables showed significant declines in the last 50 years; garden vegetables in the U.S. today contain on average 38 percent less vitamin B2 and 15 percent less vitamin C.
Very newly, genetic engineering has begun to be employed in some parts of the world to speed up the selection and breeding process. The most widely used alteration is an herbicide resistance gene that allows plants to tolerate exposure to glyphosate, which is used to control weeds in the crop. A less frequently used but more controversial modification causes the plant to produce a toxin to reduce injure from insects.