Table 4.

Cotton yields, revenue and costs per hectare for adopters and non-adopters of Bt cotton in RSA (Morse et al. 2004).

output (kg) and costs (SAR/ha)	1998/1999		1999/2000		2000/2001
	non-adopters (n=1196)	adopters (n=7)	non-adopters (n=329)	adopters (n=112)	non-adopters (n=254)	adopters (n=245)
yield	452	738	264	489	501	783
total revenue	984	1605	574	1064	1090	1704
seed cost	138	278	190	413	176	260
pesticide cost	153	72	222	104	305	113
spray labour cost	77	38	108	49	135	45
harvest labour cost	113	184	66	122	125	196
gross margin	502	1033	−11	376	348	1090
gross margin gain in US$ based on exchange rate at harvest	86		59		93