Composition of Walnut Trees as Affected by Certain Salts

Factors in Varietal Susceptibility of Walnut Fruits to Attack by the Walnut-Husk Fly

“…1) the tissue that is composed of thick-walled cells is of greater width and compactness than in the husks of the Payne and Eureka varieties (figs. 3,5). In the husks of the Eureka variety, stone cells are seen at intervals and oriented in a direction perpendicular to the surface.…”

“…Grateful acknowledgment is made for this assistance. 3 Even though rubber gloves were worn in removing the husks from the shells, the juice of the husks penetrated the gloves and stained the fingers so severely that painful flesh wounds were sustained. The results (table I) for the pH of the juices in the husks of nine varieties of walnut fruits obtained near Chino, indicate that, with one exception (Eureka), the varieties may be placed in the groups proposed by BOYCE (1, p. 379) for the susceptibility and resistance of the varieties to husk fly attack in the field.…”

“…These trees were subjected to dusts or sprays and to attacks of the husk fly. 3. With one exception (Eureka variety among the Chino samples) the pH of the juices of the husk appears to be related to the resistance to husk fly attack in the field.…”