factors must be considered as important criteria when evaluating agricultural performance
and benefits.
In summary, farmers will buy and cultivate only those elite varieties that fit best their
local needs. From the data presented here it is clear that not only does the level of pest infes-
tation and control determine yield; optimal adaptation to local cultivation conditions, such
as soil characteristics, climate, and planting and harvest time, as well as other cultivation
practices such as fertilizer and herbicide management, might influence the agronomic
benefits for farmers.
13.6 Conclusions
Both biosafety and benefits are important to regulators and consumers. Proof of safety is
more important for the regulatory side. Proof of benefits is more important for the economic
viability for the company selling the transgenic crop and the farmer who grows it.
Figure 13.5.Yield performance of three conventional (CONV1–3) and two Bt (Bt1–2) maize
variety candidates in a field testing of the Federal German Variety Testing Office
[Bundessortenamt-(BSA)]. The data on (a) ECB infestation and (b) kernel yield were pooled from
fields at three locations in ECB infestation areas spread over Germany. The ECB infestation is speci-
fied as percent of infested plants. Relative kernel yield is specified as percentage of yield compared to
three standard maize varieties. The bar graph presents mean value and standard error.
320 FIELD TESTING OF TRANSGENIC PLANTS