Crop prices sprang higher as warm weather settled over the central US, intensifying worries about corn that lifted other grains as well.

High temperatures have blanketed farm states this week at the moment that corn enters its critical pollination stage.

The 5,800 acres he farms near Lubbock, Texas, are half irrigated and half at the mercy of the clouds. And the past nine months have been the driest in Texas on record.

The Lone Star state is at the epicentre of a once-in-a-generation drought stretching from Arizona to Florida.