The figure, published today (10 August), is now 273.8 metric tonnes (Mt), down from the July estimate of 329Mt. According to the HGCA, this represents a 27% fall in production estimates from its June figure of 375Mt, following severe drought problems in the US.
The HGCA said market analysts had been expecting a figure of below 300Mt.
A smaller production of maize in the US puts pressure on wheat supplies as it is used as a substitute for animal feed, pushing the price up, as has been seen in recent months.
Elsewhere in the world, the HGCA has reported that Russian wheat production has been forecast down by 6MT to 43Mt, while Ukrainian wheat production saw estimates revised upwards, from 13Mt, to 15Mt.
World wheat production estimates stood at 662.8Mt, with consumption estimated at 649.9Mt.