IGNOU runs a 1-year course called Post-Graduate Diploma In Plantation Management that costs Rs.4,800 to take. But the entire course material is available on its sister website eGyanKosh for free. You will need to register here. Once registered you can download any or all of the following courses at the links below.
Course > Blocks > [files]
MAM-001 Introduction to Plantation Management
Block-1 An Overview of the Plantation Sector [4]
Block-2 Principles of Plantation Management [4]
MAM-002 Crop Production Technology
Block-1 Production and Management of Spices [3]
Block-2 Production and Management of Tea [4]
Block-3 Production and Management of Rubber [4]
Block-4 Production and Management of Coffee [5]
Block-5 Production and Management of Other Plantation Crops - Coconut and Cashew [3]
Also see other courses at School of Agriculture on IGNOU website (for info) or eGyanKosh (for course material)