Bulletin 208. Cucinnber Diseases in Florida


youngest leaf at the growing tip of each of the runners at the
time the spraying was done. The next leaf to develop was normal,
showing none of the markings of the burned leaf. The Bordeaux
mixture caused the leaf to become mottled, almost typical of
mosaic. A day or two later the light yellow areas became slightly
brownish and the tissue dried out and fell away, leaving a more


 Fig. 34. Copper injury resulting from spray and dust
 applications in cool weather.


or less shothole effect. The leaf as a whole, however, was not
killed. These leaves functioned until the whole plant died.
 The injury resulting in this mottling was evident on the plants
on about 1/3 of an acre. The whole patch was sprayed with
Bordeaux mixture of the same strength. During the operation a
small shower came up and thoroughly wet the plants. After the
shower the spraying was resumed. It was found later that all
the plants sprayed before the rain showed this Bordeaux injury
while those sprayed after the rain did not show this injury.
 Another type of Bordeaux or copper injury is shown in Fig.
34 in which the cucumber leaf shows a light yellow margin some-