Q.Weeping pussy willow brown leaves
Please see attached photos of weeping pussy willow leaves turned brown.
What to do please?

Willows love water, but make sure the soil is well draining.
Just to rule out some potential problems, cut one of the stems off and check for discoloration within the wood. Bacterial Twig Blight leaves brown streaks in the wood. Leaf blight is another destructive disease of willows. The best treatment at this point is to cut away the infected stems and branches, cutting down to healthy wood. Remove and destroy the pruned plant material.
https://www.gardeningknowhow.com/ornamental/trees/willow/treat-peeling-willow-bark.htm
https://www.gardeningknowhow.com/ornamental/trees/willow/willow-scab-disease.htm
https://www.gardeningknowhow.com/ornamental/trees/willow/planting-weeping-willow-trees.htm