转基因大米

Pesticide use
• The quantity of and expenditure on pesticides of non-GM rice production is 8 to 10 times as high, respectively, as those for insect-resistant GM rice. • Nonadopters applied more pesticides and spend more
Dummy variables
Dummy variable (also known as indicator variable, design variable, Boolea indicator, categorical variable, binary variable, or qualitative variable) is one th takes the value 0 or 1 to indicate the absence or presence of some categoric effect that may be expected to shift the outcome.
Introduction
A number of GM rice varieties have entered and passed field and environmental release trials, four varieties are in preproduction trials in farmers’ fields. This paper studies two of the four GM varieties that
Productivity
Parameters: Intercept
Y-intercept is the point through which the line intersects the Y-axis. It is th value of y when x equals zero. Also can be seen as a control factor whe executing the hypothesis testing and the significance analysis of their line regression trend.
This study focusd on GM Xianyou 63 and GM II–Youming
86. The two kinds of insect-resistant GM varieties entered preproduction trials in 2001. And study’s goal is to answer 3 questions: 1. Does GM rice help reduce pesticide use in the fields of
1.04 ± 2.61
–1.25 ± 3.82
–0.02 ±0.03 8.65 ± 2.65*
Included but not reported 347 347
• The insectresistant GM rice varieties could significantly reduce pesticide use • There is no statistical difference between the actual effects of the two insectresistant GM varieties on pesticide use
Research design and results Productivity
Health effects Part 3 Part 4 Conclusions of the research Group questions
Introduction
GM Rice research in China:
farmers?
2. Do the new varieties of GM rice increase the yields for farmers? 3. Are there any identifiable health effects on the farmers?
Research design and results
than adopters.
Parameter
Pesticide spray (times) Expenditure on pesticide (yuan/ha) Pesticide use (kg/ha) Pesticide spray labor (days/ha) No. of observations (plots)
Farm surveys of randomly selected farm households that
are cultivating the insect-resistant GM rice varieties
compared with households cultivating non-GM rice.
Variety dummies
GM rice, both varieties Variety-specific dummy variables GM Xianyou 63 GM II–Youming –17.15 ± 2.60* –25.33 ± 5.48*
Non-GM Xianyou 63
Non–GM II–Youming 86 Control variables Pesticide price (yuan/kg) Natural disaster dummy (affected – 1) Household dummy variables No. of observations –0.02 ± 0.03 8.65 ± 2.65*
Prodect-resistant GM rice adopters and non-adopters in preproduction trials in China, 2002–2003 (means±SD).
Parameter
Rice yield(kg/ha) No. of observation(plots)
Insect-Resistant GM Rice in Farmers’
Fields: Assessing Productivity and
Health Effects in China
Outline
Part 1 introduction Part 2 GM Rice research in China Goal of this research Pesticide use
Control variables
In an experiment, the control variable is something that is constant an unchanged. Further, a control variable strongly influences values; it is he constant to test the relative impact of independent variables.
Adopters
6364±1294 123
Non-adopters
6151±1517 224
Explanations and Conclusions: According to the descriptive data, the mean of insectresistant GM rice yields( 6364 kg/ha ) is higher than those of non-GM varieties ( 6151 kg/ha ), although only by 3.5%. ANOVA tests show that the difference between them is statistically significant.
Pesticide use
Conclusion: Insect-resistant GM rice could significantly reduce
pesticide use.
Productivity
Parameters: Rice yield(kg/ha) After control disturbance variables, weight kilograms of rice per hectare , as the mean statistical variable to measure and compare rice productivity. Descriptive statistics Descriptive statistics is the discipline of quantitatively describing the main features of a collection of information or the quantitative description itself. Adopters Refer to the insect-resistant GM rice adopters, provided with a fixed amount of insect-resistant GM rice seed. The GM rice here including GM Xianyou 63 and GM II–Youming 86.
China aggressively commercialized Bt cotton and invested
heavily into research on GM food crops(such as GM rice), however it has not commercialized any major food crops. China’s biotechnology research program has generated a wide of new technologies, including several GM rice varieties.