1) Use tapply function to calculate genotypic means and standard deviation among environments.

2) Use tapply function to calculate location means and standard deviation among genotypes.

Sample data:

Selby O nida 56 Testing locations Pierre Platte Brookings Beresford 63 88 Genotype Expedition Overland Smoky Hill Wendy Fuller Lyman Settler CL Millennium Hawken Wesley Darrell Alice Hatcher Jagalene Wahoo Arapahoe Harding Jerry Art SD06158 SD06069 Striker Radiant SD05W030 SD07165 SD051181 Camelot SD07126 Boomer SD07056 Selby O nida 56 Testing locations Pierre Platte Brookings Beresford 63 88 Genotype Expedition Overland Smoky Hill Wendy Fuller Lyman Settler CL Millennium Hawken Wesley Darrell Alice Hatcher Jagalene Wahoo Arapahoe Harding Jerry Art SD06158 SD06069 Striker Radiant SD05W030 SD07165 SD051181 Camelot SD07126 Boomer SD07056