Xij = value of each tested index
max xij = maximum value
Mini xij = minimum value.
The adjusted economic value index can be seen in Table 3.
3.3 Assigning criteria weights
The five criteria are not of equal importance. As for the economic-ecotype, the most important
one is the 100-fruit weight. According to the importance of the criteria, the proportion is as follows:
EB = 0.20
Fruit diameter = 0.15
100-fruit weight = 0.30
Single plant output = 0.20
Thorn number = 0.15
3.4 Determining the composite score
The composite score is calculated by using the following formula:
The results are shown in Table 3. Table 3 shows that the first 10 of 23 fine families come form
Fengning county, Hebei province and Ke county, lnner Mongolia.
3.5 Choosing superior economic-ecotype single plants
Based on the data shown in Table 3, and taking into consideration the five criteria, we
selected the 4 best plants to be used as high-quality seed sources for the nursery garden (see
Table 4 shows that every index or criterion of the four chosen plants was superior to that of the
control sample plants. The 100-fruit weight increased by 200%; the single-plant out put increased
by 413.8%; the ecological benefit increased by 2.1%; and the thorn number on 10 cm-long branch
of 2-year-old plants decreased by 20%.
Fu Yayu 1998. A Study on the Physiological Characteristics of Some Protective Plant in Sand Area. Forest
Science and Technology (3), Shaanxi, China.
Zhang Qide 1997. Influence of Drought on Photosynthesis. Plant Organization (3), China.