Citrus Greening: Florida's Battle to Preserve an Iconic Industry

In 2021, Florida witnessed its most disastrous orange crop since World War II. This devastation is attributed to an insect waging war on the state's valuable citrus trees. These afflicted trees are victims of citrus greening, resulting in the production of small, misshapen fruit. The contrast is stark, highlighting the destructive potential of this disease, which can ultimately prove fatal for the trees.

The culprit is an insect that carries and spreads a disease known as HLB or citrus greening. This scourge has infiltrated nearly every citrus grove across the state. The impact is evident - the canopy is visibly diminished, allowing a clear view through the tree. While the oranges remain technically edible, the real issue lies in the fact that citrus greening has slashed Florida's production by a staggering 78%, amounting to a loss of nearly 8 billion dollars. Consequently, many growers have been forced out of the industry.

Reflecting on the past 15 years, one can't help but recall the vibrant array of green trees that once thrived here. Despite enduring freezes and hurricanes, it's clear that citrus greening has emerged as the most formidable challenge in the career of many involved in the industry.

A group of determined scientists is now on a race against time, armed with innovative tools and methods. They've managed to assist growers in producing oranges from infected trees, yet a long-term solution remains elusive. The question that looms is whether they can stave off this disease before it eradicates Florida's orange industry altogether.

Larry, a fifth-generation farmer in Fort Meade, Florida, harks back to his family's citrus legacy dating back to the 1850s. At the onset of his career, citrus spanned over 900,000 acres in the state. Yet, just 15 years ago, his family was packing a million orange cartons annually, primarily of the succulent Valencia variety. It was a time when groves were established with the expectation that they would endure for generations.

The initial case of citrus screening was reported in China in 1919, swiftly sweeping through Asia and devastating citrus groves in India and Saudi Arabia. How the Asian citrus psyllid arrived in Florida remains a mystery. However, in 1998, it was discovered on an orange jasmine plant in Palm Beach County. It rapidly disseminated through the state on infected root stocks. Nevertheless, it would be another seven years before Florida's orange trees exhibited signs of greening.

For Larry, this marked the beginning of a challenging battle. Initially, he attempted to eradicate all afflicted trees, but the relentless pace of the insect soon made this approach unviable. When a psyllid feeds on a citrus tree, it leaves behind the bacteria responsible for greening. This bacteria multiplies within the vascular tissue, obstructing the crucial nutrient transport system. Over time, the root system withers, causing the tree's demise.

Although these infected trees continue to bear fruit for a limited time, the yield never ripens to full fruition. The oranges remain small and green, with an irregular shape. The juice from these oranges possesses a lower sugar content, and a significant portion falls prematurely. Ultimately, the tree succumbs to starvation, leading to its eventual demise.

To keep his trees alive and productive, Larry has implemented a combination of horticultural techniques pioneered by scientists at the University of Florida. Their ongoing research focuses on methods to extract usable fruit from diseased trees. They've even devised innovative tools like the aspirator, a small vacuum-like device, to capture the tiny psyllids.

Lauren and Brock, researchers at the forefront, are studying the movement patterns of these pests. Their findings may offer insights into deterring psyllids from citrus trees. Their experiments with pink clay and reflective mulch demonstrate promising results.

However, these are short-term solutions. The citrus industry desperately seeks a long-term fix. Scientists like Tripty Vashish delve into soil optimization, recognizing that healthier roots are better equipped to absorb nutrients. The challenge is significant, as citrus trees, due to this disease, have fewer, less efficient roots.

Larry's strategies include tailored fertilizers and planting denser groves to increase the odds of some trees surviving infection. Predator wasps and insecticides have been deployed, yet there's no silver bullet. These measures, while somewhat effective when combined, come at an additional cost to growers, further straining their already challenged bottom lines.

As of early 2022, half of Florida's orange growers had exited the industry. The remaining farmers, like Larry, persevere amidst the financial strain, determined to maintain a tradition that spans generations.

In the heart of the grove, workers diligently pick oranges and deposit them into bags. Once they've gathered a sizable batch, the pickers transfer them into baskets. The oranges are then transported to the nearby packing facility. Here, modern technology plays a crucial role, with digital cameras scrutinizing each piece of fruit. An electronic sorter divides the crop based on color, ensuring only suitably ripe oranges move forward.

In the face of HLB, Larry's packing volume has dwindled significantly over the years. To make the most of less-than-ideal oranges, some are diverted to the juicing process. Larry owns a juicing plant as part of a cooperative venture with fellow growers. The plant, too, faces challenges due to reduced fruit volume. Efficiency suffers, with one processing line forced to shut down.

Long-term hope lies in re-engineering nature, with efforts to breed HLB-resistant orange varieties underway at the University of Florida. Fred Gameter and his team embark on the painstaking task of crossing different types of trees, aiming for a hybrid that retains flavor without succumbing to HLB. However, such endeavors demand time and serendipity.

In the grand scheme, the battle against citrus greening is part of an ongoing struggle against the ever-evolving landscape of agricultural challenges. It's a testament to the resilience and adaptability of both the citrus industry and the scientific community. While citrus greening remains a formidable adversary, the quest for innovative solutions persists, driven by the belief that science will continue to deliver new tools to fortify the future of citrus cultivation.