Farmers in Tanzania use pesticides to combat harmful moth, endangering biodiversity

Tabia Omary working on her farm. Photo by Goodhope Amani, used with permission.

Kipera Village, situated in the Mvomero district and 25 km (16 miles) from the Morogoro region of eastern Tanzania, is renowned for its tomato farming. Tabia Omari and Rajab Hassan have been dedicated tomato growers for over 30 years. However, in recent times, a surge in diseases has compelled them to rely excessively on pesticides. This not only harms the environment but also takes a toll on the farmers’ economic stability. The main source of their woes is a small moth, Tuta absoluta, that has become a serious threat to tomato farmers all over Tanzania, prompting them to intensify pesticide usage in an attempt to get rid of this pest.

It's essential to note that Tanzania's agricultural landscape is primarily composed of small-scale farmers, with approximately 75 percent of the workforce relying on agriculture for both sustenance and economic prosperity.

Tomatoes have been exposed to pesticides. Photo by Goodhope Amani, used with permission.

Biodiversity encompasses the wide array of living species on Earth — animals, plants, fungi, and bacteria. These diverse organisms collaborate to maintain balance within the ecosystem and the natural world. However, the proliferation of pests like Tuta absoluta has compelled farmers to resort to an overuse of pesticides in horticulture farming, posing a significant threat to biodiversity. Tanzania's principal horticultural crops are tomatoes, cabbages, onions, carrots, potatoes, mangoes, oranges, and flower seeds.

In an interview with Global Voices, Tabari Omari shared her concerns about modern farming practices while offering a tour of her one-acre farm, which incurred approximately USD 1,800 in operational costs covering everything from planting to harvesting in a single season of around 3 months. She said the traditional farming system didn't incur such high costs, and expressed her apprehensions about the long-term sustainability of the new practices:

From the moment you plant your seeds, you have to start applying pesticides until you harvest. Currently, Tuta absoluta requires frequent chemical application — almost every week.

The moth did not exist here in the past 10 years, but according to farmers and researchers, climate change has triggered their widespread presence now. Even though there are certain pesticides effective against various pests and diseases, Omari stressed that dealing with this moth is a unique challenge. This persistent insect poses a significant threat; a single misstep could lead to devastating consequences. This moth consumes the vital green parts of the leaves essential for photosynthesis, hindering the plant's ability to produce their own food.

The surge in pest populations has also escalated costs, necessitating farmers to toil excessively to yield any produce.

According to Rajab Hassan, another tomato farmer whom Global Voices interviewed, the escalating prices of pesticides are a burden:

The impact of climate change on farmers has been substantial. Horticulture, in particular, has seen a rise in various diseases, significantly driving up production costs compared to the profits gained. Pesticides and fertilizers have become prohibitively expensive, and prolonged droughts worsen the situation. Pesticides for Tuta absoluta, for instance, are sold at around USD 90 for a single bottle, which can be used for one acre. Just imagine the cumulative cost from the beginning till harvest. In the good old days, we didn't use pesticides, but now we're applying them every week.

He stressed that government agriculture officers have agricultural knowledge but they do not visit farmers regularly to provide professional support to farmers, such as better methods of fighting pests and proper pesticide usage, and this further compounds the challenges.

Research has proven that excessive pesticide use harms biodiversity, underscoring the importance of safeguarding biodiversity, which is why at COP 15 conference in Montreal, Canada, government leaders committed to this crucial goal last December.

Vitalis Fabian, an agro-input dealer at Morogoro Town pointed out that many farmers misuse pesticides and disregard prescribed instructions. They tend to overuse pesticides, hoping to eliminate diseases, but inadvertently end up harming other species.

“Most of the time, farmers decide on their choice of pesticides without seeking advice from experts. Often, their application deviates from the manufacturer's intended usage,” Vitalis told Global Voices.

Vitalis Fabian explains how pesticides are misused. Photo by Goodhope Amani, used with permission.

A study commissioned in 2018 by the Tanzania Plant Health and Pesticides Authority (TPHPA) revealed that over 20 different pesticides contained components detrimental to the environment. Subsequently, the importation of these pesticides was prohibited, as Rafael Mwezi of TPHPA explained. 

Mwezi works at the office of the registrar of pesticides at TPHPA. He told Global Voices that despite having the best laboratory for chemical testing, a major challenge is untrustworthy business people who import pesticides illegally. Nevertheless, he assured that the Authority diligently ensures that legally imported pesticides undergo thorough testing and registration before they are distributed to consumers:

Before the importation of pesticides, we do take samples for testing in our modern laboratory to ensure they are good to be used. We don’t just end there; we also do post surveillance study to ensure that whatever is registered in our books is what is being sold and used by our people.

While world leaders grapple with the dual objectives of environmental preservation and food security, Sokoine University of Agriculture (SUA) in Morogoro has actively been engaging in regional efforts. For years it has been doing a number of studies on how to improve farming. However, a persistent impediment has been the reluctance of farmers to fully embrace and implement their research findings. 

Dr. Martin John, a researcher from the Institute of Pest Management at Sokoine University of Agriculture, emphasizes the adverse impact of pesticide usage on non-targeted organisms:

We are well aware that the utilization of pesticides has multifaceted effects on the environment, human health, and various microorganisms. Pesticides not only harm the intended pests but can also have detrimental effects on beneficial species like bees and butterflies, crucial for plant pollination. Additionally, studies have shown that pesticides negatively affect the soil, inhibiting small microorganisms that provide essential nutrients to plants. Hence, we strongly advocate for farmers to adopt alternative pest control methods, such as timely farm cleaning and employing other scientifically researched approaches, to minimize pesticide use. 

During a tour with Global Voices, Dr. John showcased alternative pesticide methods, including a well-designed yellow trap resembling a bottle with holes at the top, effectively capturing flies that pose a threat to fruits. He also demonstrated a black box-like contraption used to contain rotting fruits, preventing destructive insects from harming nearby plants.

Dr. Martin John, an agricultural researcher at the Sokoine University of Agriculture, demonstrates one of the bio-control methods of fighting pests. Photo by Goodhope Amani, used with permission.

He stressed that when these eco-friendly methods are appropriately utilized, farmers can significantly reduce their reliance on pesticides. These methods have proven efficacy, and researchers are diligently working to advance them further.

Bio-control methods for managing pests offer various advantages. For example, the fly traps can attract pests within a 200-meter radius and serve as monitoring tools for pest presence on the farm. While they may not act as swiftly as pesticides in eradicating and controlling pests, they provide assurance that the crops remain safe for consumer health.

The Living Planet Report of 2022 reveals a concerning trend, indicating that approximately 69 percent of global biodiversity has been lost since 1970. This alarming statistic underscores the urgent need for collaborative efforts involving farmers, governments, and concerned citizens to preserve biodiversity. The loss of biodiversity will have far-reaching consequences, affecting not only insects but the entire ecosystem, including human beings.

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