FRENCHING OF RAGWEED ( AMBROSIA ARTE , lIISIIFOLIA L . )

Typical frenching of tobacco (Nicotiana tabacum L.), as described by WOLF (8), is recognized as producing short internodes, loss of apical dominance, and the development of a rosette of many leaves (polyphylly), giving a witches'-broom effect. The first symptoms appear as a pinhead chlorosis, followed by very chlorotic, newly developing leaves which… CONTINUE READING