I have five Sprout plants growing in a 4 x 12 foot raised bed. The leaves on a plant at one end started drooping although all the rest are still healthy looking. There is some white fly on the plant and the actual sprouts. I have dug the plant up and the roots appear to be extremely healthy with no sign of pests. I chopped the stem in half with a spade and it too seems to be healthy. The plants have been covered with enviromesh since planting to keep off the cabbage whites. Have you any idea what can be causing this plant to droop as I don’t want to loose the others this way?
and the recent dry weather, if you are in SE England, will have contributed, I would water the remaining plants, it may be a one off. Sometimes the odd plant just fades, for no obvious reason, and the others are fine. The symptoms you describe are cabbage root fly, but usually it is young plants most affected and in early summere, not now; again, watering would help in dry conditions.