Hybrid seeds are the result of cross-pollination (or genetic engineering, discussed separately on this website), carried out for specific purposes, usually higher production, resistance to specific plant diseases or for a specific attribute such as shape or colour. Hybrid crops are also more input-demanding, whether for water or nutrients; have specific requirements which need to be met in order for the plant to ‘perform'; are not as healthy or hardy; are often highly pest- and disease-prone; and importantly cannot produce seeds that are true to the parent plant, or may even produce sterile seeds. In other words, farmers have to buy their seeds each season. In all these respects, indigenous or traditional seeds score over hybrids.
While most hybrid plants do ensure a higher production to begin with, this is also accompanied by higher costs of cultivation, starting with the high cost of seed and including higher doses of inputs like fertilisers, pesticides and water. The effect of regular hybrid crop cultivation is felt by the soil and results in ever-increasing doses of chemical inputs as the soil health keeps falling. The use of hybrid seeds is therefore a major part of the “chemical-agriculture problem”.
To know more about hybrid seeds and their negative impact on agriculture systems, you may follow this link :
http://www.btinternet.com/~bury_rd/heritage.htm