Final answer:
Hybrid corn requires farmers to start reseeding every year to maintain better results in terms of yield and productivity.
Step-by-step explanation:
Hybrid corn is a result of plant breeding techniques that involve crossing two inbred lines to create a more vigorous and productive offspring. However, hybrid corn cannot be stored and used for the next year's crop because the offspring of hybrid plants are less vigorous and more variable. Therefore, farmers need to purchase new hybrid seed each year or switch to using open-pollinated seeds.
For example, in the 1970s, the southern leaf blight had a significant impact on corn production in the US because all the corn strains were hybrid seeds developed using the same cytoplasmic male sterility factor. This uniformity made them susceptible to a novel strain of fungal pathogen, resulting in reduced yields.
Overall, while hybrid corn offers better results in terms of yield and productivity, farmers have to start reseeding every year to maintain these benefits.