In the Kings Landing page, under the "A Clash of Kings" headline, mention this:
"...During the War of the Five Kings, the capital is cut off from trade and food supplies by the blockade of Lord Mace Tyrell, a supporter of Renly."
This sentence have a reference note of Chapter 17, Tyrion IV. However, in that chapter there is no mention of the blockade itself, nor mention about it being done by Lord Tyrell, only discussing its. Chapter 3 Tyrion 1 seems a better choice.
Also, why Lord Mace Tyrell? In the aforementioned chapter 3, Vylarr said:
"With the war in the riverlands and Lord Renly raising rebels in Highgarden, the roads are closed to south and west.”
Thus not only Renly should be named, but also the ravage of riverlands.
Hope some editor can provide their insight.