China: More vegetable crops
Paraquat enables faster crop production for farmers in Guandong, China. This case study is based on an article by Mr. Shen Shu Ping of South China Agriculture University, published in the Chinese Journal 'Pesticide Information'.
In the Guandong region there are one million hectares of high-quality vegetables and up to eight crops are grown each year on the same land. Under such intensive cultivation, a rapid turnaround between crops is essential if farmers are to maximize production.
To achieve this, after harvest weeds and trash must be cleared quickly and the next crop sown or planted within a few days. It is not surprising, therefore, that paraquat is used on over 40% of the vegetable area in Guandong.
The vegetable farmers of Guandong use paraquat in several different ways. First, it is sprayed as a pre-plant treatment, often in tank mixture with a fertilizer or with butachlor (another herbicide) to provide residual weed control. Paraquat has also been widely adopted for inter-row weeding and after harvest it is used to desiccate stubbles, trash and any remaining weeds.
Paraquat's speed of action is key to its success. After spraying, weeds are killed within one or two days and during this period the land can be prepared for the next crop without delay. In addition, because paraquat is completely inactivated upon contact with soil, the crop can be sown or planted safely as soon as the soil is ready. With systemic herbicides, farmers would have to wait for 10 days after spraying before beginning work on the next crop. With eight crops per year, this would represent a loss of 80 days of crop production.