from Amer Phytopathological Society (June 1, 1971)
| details & prices
| 4.50 × 7.25 × 0.50 in. | 0.35 lbs | List price $24.00About:
Each key is segmented according to the growth stage of the plant and refers users to illustrations of disease symptoms as well as to disease descriptions and guidelines on the back of each page for making disease assessments.