Q.splitting orange fruit
Does spraying roundup on the ground around the navel orange tree cause the oranges to split? I sprayed roundup around the base of my navel oranges trees to prevent weeds from growing. Now the navel oranges are splitting on the tree.

The oranges splitting is likely due to the fruit receiving to much water near the end of their ripening.
Here is a link that will explain this.
https://www.gardeningknowhow.com/edible/fruits/oranges/oranges-splitting.htm
Always use chemical herbicides carefully as overspray can kill the citrus.
https://www.gardeningknowhow.com/plant-problems/weeds/glyphosate-information.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-long-does-weed-killer-last-in-the-soil.htm