Fusarium toxins harm both wheat and human health
"This year the Fusarium head blight is too severe; the wheat definitely won't fetch a good price."
"But do you know that Fusarium head blight produces toxins?"
Faced with the reporter's question, Han Hongchang, a large-scale grain farmer in Jiangyan, Jiangsu, could not answer. In Jingjiang, Jiangsu, large-scale grain farmer Zhou Renjie also only knew that wheat with Fusarium head blight was of poor quality, and knew little else.
Since June this year, reporters from Science and Technology Daily have found through visits that, due to the large-scale outbreak of Fusarium head blight, the lack of warning publicity by relevant departments, and the lack of rapid detection methods and equipment, the public knows only one side of the harm of Fusarium head blight and not the other, and the harm of Fusarium toxins in wheat is not well known to the public.
The "invisible killer" Fusarium toxins
"Compared with the yield loss caused by Fusarium head blight, the harm produced by the fungal toxins in wheat is greater; this is the 'invisible killer' that needs to be guarded against," said Professor Zhou Mingguo of Nanjing Agricultural University.
While Fusarium infects wheat, it also produces mycotoxins mainly composed of deoxynivalenol (that is, the vomitoxin DON). Eating diseased wheat can cause acute poisoning symptoms such as dizziness, fever, nausea and diarrhea, and in severe cases can cause bleeding and affect immunity and fertility.
As an internationally recognized Group 3 carcinogen, DON toxin is strictly limited in content in food by all countries.
Entrusted by the Food Safety Inspection Bureau of the Ministry of Agriculture, the Institute of Food Quality Safety and Testing of the Jiangsu Academy of Agricultural Sciences has continuously conducted DON toxin testing on wheat from Jiangsu and surrounding areas since 2012. According to Science and Technology Daily reporters, there are 6 such testing centers nationwide.
How to dispose of "toxin-containing" diseased wheat
"Your two lots of wheat have unsound kernels as high as 99%, and the lowest is 61%; this is substandard wheat, and the grain depot cannot purchase it."
On June 10, large-scale grain farmers Shen Jinshui and Cheng Shengxiao brought their harvested wheat to the Hefeng Grain Reserve Depot in Lishui District, Nanjing, but the test results chilled them to the bone.
Ru Baisheng, head of the grain depot, said that national regulations stipulate that the unsound kernel content of Grade 3 wheat shall not exceed 8%, and that of Grade 2 shall not exceed 6%; the wheat of Old Shen and Old Cheng seriously exceeded the standard for unsound kernels.
"DON toxin is highest in the bran of the wheat kernel, and fine processing methods can effectively remove it," said Dr. Qiu Jianbo of the Food Inspection Institute of the Jiangsu Academy of Agricultural Sciences.
Prevention and control of Fusarium head blight requires the right remedy
"In 2015, we collected more than 5,900 Fusarium strains in Jiangsu, and 60% had drug resistance," Zhou Mingguo said. "The urgent task is to remove carbendazim from the pesticide list for controlling Fusarium head blight and encourage enterprises to develop and farmers to use new agents."
He has called loudly for this suggestion for many years, but the results have not been obvious.
"The central government has special prevention and control funds, and this year 146 million yuan was allocated to Jiangsu, but it can only cover 70% of one spraying, while the province applies an average of 2 sprayings/mu," said Wu Jiawen of the Jiangsu Plant Protection Station. They are also calling on relevant national departments to increase investment to ensure that all wheat can enjoy free prevention and control of 1 spraying/mu.
On the other hand, how to find effective fungicide resources and break the "dead cycle" of both the dosage and drug resistance surging has become the key to improving the efficiency of comprehensive prevention and control.
In 2011, the new anti-Fusarium head blight agent phenamacril was successfully developed by the Jiangsu Pesticide Research Institute. This drug was independently innovatively developed in China, and its mechanism of action is completely different from traditional drugs such as carbendazim, with outstanding field efficacy. In the past two years, Zhou Mingguo has also led the development of the NAU series of biochemical agents, which have a good effect on inhibiting the formation of DON toxin, with a maximum reduction of 67.2%. The series of control agents developed by the Jiangsu Academy of Agricultural Sciences can also effectively control the occurrence of wheat Fusarium head blight, and have inhibitory and degrading effects on the breeding of DON toxin, reducing it by 40%-60%.
"At present, the disease is not yet so serious in the main wheat-producing areas such as Henan and Shandong, and we cannot miss this precious window period again," Zhou Mingguo appealed, saying that wheat is one of China's most important staple grains, and the harvest and quality of the northern wheat regions are directly related to national food security and social stability. The problem of Fusarium drug resistance that occurred in Jiangsu must never be repeated in other wheat regions.