Blight
Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are:
Chlorosis
Like many other plants, grape vines are susceptible to chlorosis, and symptoms of iron deficiency tend to be common on soils rich in limestone. In the wake of The Great French Wine Blight, when European "Vitis vinifera" were affected by "Phylloxera", chlorosis became a greater problem in viticulture. To deal with the Phylloxera blight, "V. vinifera" was grafted onto rootstock based on American species of the genus "Vitis", such as "Vitis riparia", "Vitis rupestris", "Vitis berlandieri". However, many of these were less adapted to the lime-rich soils that were common in France's vineyards, in particular many of those that produced wines of top quality. Many grafted vines in lime-rich vineyards therefore showed signs of iron deficiency, and in France this specific form of chlorosis was termed "chlorose calcaire." The problem was largely overcome by the selection of lime-resistant American vines as basis for hybrid vines used for rootstock material. However, since such rootstocks may be less than optimal in other respects, it is necessary for the viticulturalist to balance the need for chlorosis resistance against other viticultural needs. This is illustrated by one of the most common lime-resistant rootstocks, 41 B, which is a hybrid between "V. vinifera" cultivar Chasselas and "V. berlandieri", which generally has a sufficient, but not extremely high, Phylloxera resistance.