Did you know that most GMOs on the Non-GMO Project High-Risk List are commodity crops? These GMOs are processed into low-nutrient ingredients that appear in an estimated 80% of packaged goods sold in stores. 

And then there's papaya. Papayas are also considered high risk for being GMO because most US-grown papaya is genetically modified for disease resistance. However, it's different from most other crops on the High-Risk List. While many other GMOs were produced by huge agrichemical corporations, GMO papayas were developed by researchers at the University of Hawaii. Plus, papayas are usually sold fresh or frozen, not as ultra-processed additives in packaged goods. 

Let's look at the outlier on the High-Risk List — the GMO papaya. 

Getting to know papayas

Papayas are technically berries that grow on tall, tree-like plants. They are native to Central America and do well in tropical climates. Modern papaya farming takes place in Asia, Africa, and the Americas. Common varieties for US markets include the small, solo-type grown in Hawaii, which usually weighs less than 1 lb, and the larger Maradol varieties produced in Mexico, which weigh 3-5 lbs.

Papayas are susceptible to various insect pests, including the papaya whitefly, papaya webworm, hornworms, leafhoppers, aphids and scale insects. Insects can also act as vectors for disease. One of the greatest threats to papaya production, a pathogen called Papaya Ringspot Virus (PRV), is spread by aphids as they move from one plant to the next. A papaya plant infected with PRV develops discolored and mottled leaves and suffers from stunted growth. Young plants might die quickly, while older ones produce small quantities of substandard fruit with distinctive "ringspot" markings. 

PRV is a global problem for papaya producers. Wherever papayas are grown, PRV is there.

The problem with papayas

Papayas were first introduced to the Hawaiian islands in the 1800s, and commercial cultivation began the following century. During the 1950s, PRV was discovered in commercial plantations on Oahu. Papaya production shifted to the Big Island in an attempt to outrun the pathogen, but this strategy was unsuccessful. By the mid-2000s, Hawaiian papaya production had fallen by more than 50% because of PRV.

Researchers at the University of Hawaii were looking for a solution to protect the papaya industry and turned to biotechnology. They inserted viral genes into the papaya to impart PRV resistance, like a vaccination. PRV-resistant GMO papayas are available today as the red-fleshed SunUp and the yellow-fleshed Rainbow varieties.

After regulatory agencies approved GMO papayas in 1998, commercial growers quickly adopted them. Since then, the media and biotech industry have touted Hawaii’s GMO papaya as a shining example of how genetically modified crops are an unquestioned success. 

The papaya question(s)

GMO papayas have so far been effective at reducing PRV, but the road has had some bumps. Adopting GMOs meant that some countries that didn't accept GMOs closed their doors to Hawaiian-grown fruit, and organic farmers risk GMO contamination as pollen drifts from genetically modified plants. The industry facing a destructive pathogen was ultimately reshaped by the GMO varieties adopted to resist that pathogen. PRV has evolved in China to evade the GMO papayas' defenses.

Another question is about the purported necessity of GMO papayas. If PRV poses an existential threat to the papaya industry that only GMOs can avoid, how do other papaya-growing countries continue without them? India, for example, is the world's largest producer of papayas, but the only GMO crop approved for commercial cultivation is Bt cotton. Or Mexico, which is another papaya powerhouse. The US imports 80% of the papayas we consume from Mexico, where PRV is present in papaya-growing regions, but GMO papayas are not. According to recent reports, the papaya industry in Mexico is flourishing. 
GMOs continue to attract controversy in Hawaii, where biotech companies take advantage of the long growing season to develop GMO seeds for sale on the mainland. In recent decades, a passionate and dedicated movement against GMOs and pesticide spraying has emerged, with citizens demanding a more sustainable food system that protects Hawaii’s environment and people. Let’s hope their voices will be heard, and the safety, health, and values of this beautiful island paradise will be preserved for generations to come. Take part in the movement by choosing USDA organic or Non-GMO Project Verified papaya.