Portions of leaves shaded by other leaves or leaves on the shaded northeast side may be undamaged. A recognizable pattern related to leaf tissue that would have the highest potential temperature and be most readily desiccated will occur uniformly over all plants in the area. For example, frost damage to foliage , i.e. conifer needles, in the spring will uniformly kill all needles of a given age from the tip of the needle back toward the stem a given distance on each needle. Frost cracks are longitudinal separations of the bark and wood generally on the southwest sides of the trunk-most likely to occur because of daily, wide temperature fluctuations. Freezing death of dividing cells on outer portions of leaf folds inside the bud will cause distorted or lace-like leaf blade because of nonuniform cell division and growth during leaf expansion.
Plants respond adversely to rapid changes in the environment.
Flowering will be reduced, delayed or absent under low light. Here we are primarily considering the root environment where oxygen and moisture are inversely related. Consequently, uptake of water and nutrients is restricted with subsequent wilting and nutritional deficiency symptoms occurring on the above ground portions of the plant. The pattern of plant injury in a field or other group of plants and date of injury appearance can be helpful in relating the damage to a specific chemical application. Illustrations of patterns of plant damage related to chemical applications to field or bed plantings.