Punjab may be the breadbasket of the country, but not only are its traditional wheat-growing areas producing less, overall productivity in the state has stagnated and is even on the decline.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/declining-yield-causes-worry
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/tribune-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agriculture
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/food-crops
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wheat
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/crop-yield
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/punjab
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fatehgarh-sahib-d
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sangrur-d
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/food-security