Paraquat is one of the most widely used herbicides in the world, marketed globally under the brand name Gramoxone by Syngenta. A list of other brand names under which paraquat is sold can be found here.
Paraquat is used in nearly 90 countries either to prepare the land for planting or for controlling weeds in more than 100 crops, including major food crops: corn, rice, soya, wheat, potatoes; major fruits: apples, oranges, bananas; beverages: coffee, tea, cocoa; and processed crops: cotton, oil palm, sugarcane, and rubber.
In this section you can find information about crops for which paraquat is an essential production tool and a selection of case studies illustrating the benefits from using paraquat in some very different cropping systems.
The crop reviews describe the crop, where it is grown and what it is used for; crop production methods and weed, insect pest and disease problems; and the key benefits from using paraquat. They are summarised here and more extensive articles can be found in the Knowledge Bank.
The case studies demonstrate why paraquat is an essential tool for use in sustainable agriculture, and one which many farmers around the world rely upon for their livelihoods and to support their families.

Paraquat has been a valuable tool for farmers all over the world for nearly 50 years. Its speed of action, rainfastness and now its role as a weed resistance fighter are unsurpassed.
However, paraquat’s importance and benefits go beyond simply weed control. Its unique property of being locked onto soil so tightly on contact, and the consequent biological inactivation, mean that it has become a key component in conservation tillage systems, especially no-till.
Paraquat plus reduced tillage improves soil structure and fertility, timeliness of operations, biodiversity and the overall profitability of farming. It is also unique as a non-selective herbicide in being able to be sprayed between the rows of growing crops without fear of crop damage.
In this section you can find out about the specific benefits paraquat brings on the farm, for the environment and in rural communities.
Key benefits of paraquat
On the farm For the environment In rural communities Controls weeds
Reduces [no-glossary] soil erosion
Creates opportunities
Acts fast
Increases soil organic matter
A variety of plant materials, technically called ‘biomass’, can be processed into biofuels. Biodiesel is the product of vegetable oils derived from soybeans, sunflowers, rapeseed, palm, coconuts, and other more exotic sources such as jatropha seeds. Bioethanol comes from the fermentation of corn, sugar beet and sugar cane, switchgrass, and wheat, as well as other starchy or cellulosic plant material.
Ethanol use far outstrips biodiesel globally, as ethanol has more mature markets and infrastructure. In the U.S., where it is mostly produced from corn, ethanol has been blended with gasoline for many years.
An October 9, 2006 article entitled “The Story of Gramoxone and No-tillage in Sichuan” (in Mandarin) appeared in the SanNong Online. Written by Chen Hongbo, the article details the process through which local Sichuan farmers discovered and achieved success with no-till farming systems with the aid of paraquat.
The adoption of no-till farming methods using paraquat has enabled farmers in this province to significantly reduce costs, labor and precious water resources while enabling them to increase yields and rotate crops even during the difficult rainy season – resulting in increased income.
Paraquat Supports No-Tillage Systems in Sichuan, China
Sichuan enjoys a unique climate due to the region's uncommon and varied topography and the influence of alternating weather patterns. In winter, Sichuan's climate is dry with little rainfall. Sichuan gets abundant rainfall from April to October, but in the west of the province, the rainy season is from May to September. This climate makes it difficult to rotate crops by conventional methods. Conventional tillage also leads to and reduces the filtering capacity of soil – it can also cause a delay in planting and yield loss.
With the help of paraquat in no-till cropping systems, farmers can manage crops more effectively and make sure they can plant and harvest in one single season.
Additional evidence of the benefits of paraquat was revealed at the 20th Asia Pacific Weed Science Society (APWSS) congress in Ho Chi Minh in November 2005, where results of a study showed that no-till rice farming methods using paraquat significantly reduced methane emissions.
The study, entitled, “The Effect of Water Regime and Soil Management on Methane (CH4) Emission from Rice Field” was a collaborative effort between Syngenta Research and Development Station, Cikampek and Agricultural Environment Preservation Research Station, Jakenan, in Indonesia. Syngenta is a leading manufacturer or paraquat.
Field data collected over the one-year study examined the effects of different watering systems as well as different tilling systems and showed that no-till systems reduced methane emissions by 43% compared to normal-till methods in Indonesia’s wet season.
The researchers concluded that “the best CH4 gas mitigation option in terms of benefit gain and CH4 reduction was the zero tillage, combined with intermittent/saturated water regime plus application of 0.4 kg a.i. paraquat/ha before transplanting….”
Methane reduction
Weeds. A single word that can strike fear into the hearts of farmers around the world. And it is no wonder. Effective weed control is essential for successful crop production - especially when using conservation tillage systems such as no-till or zero-till systems. These systems are designed to prevent soil erosion and reduce labor and fuel costs. However, in his article, entitled, “Weed Control Considerations for Conservation Tillage,” author Roger Veseth writes: “…lack of adequate weed control is one of the most frequently cited reasons for failure of conservation tillage systems.” While there are a number of integrated strategies that can be used to manage weed populations, in practice the sensible use of herbicides remain an essential tool for a sustainable, profitable production system.
Paraquat’s contact-only action allows farmers to control weeds without killing the weed root structure, making it an ideal herbicide for use in conservation and no-till systems. In fact, in addition to reducing soil erosion and improving soil moisture, field studies have shown that in no-till systems using paraquat:
Organic matter increases
Carbon dioxide emissions are reduced by allowing the soil to act as a better carbon sink
Microbial populations and surface microarthropods numbers increase
Field demonstration programs in West Bengal prove that using paraquat and no-till/thrown seedling technology in irrigated rice is enhancing rice paddy production in India. First response from farmers was extremely skeptical, but seeing is believing…and response from government officials has been extremely positive.
Paraquat and no-tillage are providing a solution that minimizes the cost and number of days required for rice cultivation for paddy farmers in West Bengal.
“Minimizing costs includes the cost of plowing, which is about Rs. 2250 to 3000,” commented Mr. Tapas Kundu, District Plant Protection Officer, North 24 Parganas, for the Goverment of West Bengal’s Department of Agriculture.
He goes on to explain, “Normal practice to transplant rice seedlings requires 12 to 14 days for land preparation, including one or two days of plowing and eight to 10 days of stoppage to allow the weeds to decompose before the farmer gives the field a final plow and levels the field for rice transplanting. By using paraquat, a farmer can manage his main field to make transplant in just four days. So, he can save an average of 10 days using this method and can use this time for his next crop, like early potato, tomato, and other vegetables, which fetch an attractive market price.”
What is Paraquat?
Paraquat is a herbicide (chemical weed killer) used to control a very broad range of weeds (unwanted plants) in more than 100 crops, including cereals, oilseeds, fruit and vegetables, growing in all climates. Weeds shade crops, take their water and nutrients, and make harvesting difficult. The leading manufacturer of paraquat is Syngenta, which (as ICI) developed the active ingredient (AI) in the early 1960’s. Since then, paraquat has made possible many innovations in sustainable farming systems, based on its simplification of crop production by effectively controlling weeds and, in doing so, removing the need for ploughing to bury them. This has freed up farmers’ time and also helped care for the soil. Paraquat is one of the most widely used herbicides in the world. It has been approved for use by authorities in nearly 90 countries. When used as recommended, paraquat is effective and safe to users, consumers and the environment.
Key facts about the safe and effective use of paraquat are noted below. This fact sheet also contains a list of referenced scientific papers and other publications and a summary of technical information.
Why Farmers Use Paraquat
Spraying paraquat lets millions of farmers grow better crops more easily, while respecting the environment. Paraquat has a unique set of characteristics: