Intercropping, i.e., planting alternating rows of two different crops in the same field, is used as a management tool to control early leaf spot in peanut. The following experiment to compare four different intercropping treatments (monoculture, monoculture with fungicide, alternate rows of peanut and corn, and alternating four-row strips of peanut and corn) is proposed.

(1) Randomly assign five plots to each intercropping treatment.

(2) Place fungus inoculum in the center of each of the 20 plots.

(3) At 6 weeks after planting, measure disease at three locations in each plot.
(a) What is the experimental unit, and how many units are there?
(b) Randomly assign the four treatments to the 20 plots.

[此贴子已经被作者于2008-8-28 0:50:27编辑过]