ANTHRACNOSE OF CUCURBITS. JUL 
On muskmelon the leaf lesions are quite similar to those on ¢ucum- 
ber. The attack on petiole, stem, and fruit is more severe. Petiole 
and stem lesions are sunken and dark colored, penetrating deeply 
and finally girdling. A red gummy exudate is often present. Fruit 
lesions vary with the host variety (Pl. III, A and B) and are less 
conspicuous on the netted varieties. In general, fruit lesions are 
oval or circular and sharply depressed (Pl. III, B). On some varie- 
ties the depressed epidermis may form a white background for the 
pink spore cushions. The latter are represented by black dots after 
sporulation ceases and may be arranged in concentric lines if the 
lesion is on the upper exposed surface of the fruit. Rotting of the 
fruit in the field may result from anthracnose lesions on its lower 
surface. 
In the field, anthracnose of muskmelons is characterized by rather 
complete defoliation, due to the severity of petiole attack, and by 
the death of whole runners. Fruit lesions are also very conspicuous. 
The symptoms on watermelon have been well described by Sheldon 
(46). On watermelon leaves the lesions are black rather than brown 
(Pl. IV). Petiole and stem lesions resemble those on muskmelon in 
appearance and severity, and as a rule such lesions cause the death 
of the distal portions. Infection of young fruits results in their 
abortion or malformation. Small lesions on such fruits are black 
depressed spots, soon bearing pink acervuli (Pl. V, (@). On older 
fruits the lesions first appear as elevated pimples with a yellow trans- 
lucent center. More common on mature fruits is the nailhead type, 
consisting of a rather flat-topped, circular, water-soaked elevation. 
Such lesions soon become sunken and bear the familiar pink spore 
masses on a black or cream-colored background. Lesions on the 
under side of the melon where it is in contact with the soil may become 
black and corky. It is from lesions thus situated that rotting in the 
field may result. 
In the field, watermelon anthracnose is characterized by the 
scorched appearance of the foliage and by the bare, leafless areas at 
the centers of, the hills, the stem lesions, and the disfiguration of the 
fruit. 
On Lagenaria vulgaris, or gourd, the leaf lesions are also black 
and the petiole and stem lesions resemble those on muskmelon and 
watermelon. Lesions on young fruits are black, while on older white 
fruits the lesions are brown at first, with conspicuous yellow and 
water-soaked borders, and crack transversely while rather small 
Cale Nae : 
Thesymptoms on Cucumis melo var. dudaim, C. melo var. flexuosus, 
and the mango melon are much like those on muskmelon. On the 
leaves of Cucumis dipsaceus the spots are very light tan colored. 
Fruit lesions on T'richosanthes colubrina are illustrated in Plate V, A, 
and on the mango melon in Plate V, B. 
