This paper documents the yield gains attributable to the breeding and distribution of new cocoa varieties in Ghana, using data from a 2002 survey of 192 fields in the country's key cocoa producing regions. We find that planting the more recently-released varieties is associated with at least 42 % higher yields, and that genetic improvement accounts for much but not all of the observed correlation between tree age and cocoa yield. Fertilizer use is also very important, being associated with 19 % higher cocoa yield per 50 kg bag of fertilizer. We find no evidence that varieties differ in their response to fertilizer, pesticide use or labour, and no evidence of a decline in the yield advantage of new varieties over the 17-year age span observed in the sample.

This study investigated how agricultural education programs prepare teacher education students for work in diverse situations. It assessed the extent to which agricultural education programs are infusing diversity, multiculturalism, and pluralism into their curriculum as courses, field experiences, and in-service for current teachers. This census study included all universities with an agricultural education program as identified in the 2005 Directory of Agricultural Education on the American Association for Agricultural Education (AAAE) website. The instrument was web based and was accessed by 57 program leaders. The program leaders indicated their agricultural education programs provided students with instruction on diversity through required courses, optional courses, or infusion of these topics into agricultural education courses. Results showed that students are involved in early field experiences and student teaching in settings where agricultural education undergraduates interact with people different from themselves. Coursework on diversity and in-service offerings for current teachers showed more mixed results.