. Bulletin. 1901-13. Agriculture; Agriculture. 14 A SOFT K«»r OF TilK CALLA LILY. mis rt'inains iiitait, lliiu pirM'ntiiii^- tin- ;4)iH'ariinc(' of thin-walled tubes tillt'tl \N itli II soft sul»staiu*e. The roots rciiiaiii attached to tlie coriu and eventually the slimv contents dry uj) and only the dead skin of the roots remains. When the disease begins its attack below the surface of the ground the lower portion of the corm freijuently rots away, causini^ the plant to fall o\ er without ha\ in»^- previously j^ivcn any indication of dis- ease. An examination of the decayed corm shows that on
. Bulletin. 1901-13. Agriculture; Agriculture. 14 A SOFT K«»r OF TilK CALLA LILY. mis rt'inains iiitait, lliiu pirM'ntiiii^- tin- ;4)iH'ariinc(' of thin-walled tubes tillt'tl \N itli II soft sul»staiu*e. The roots rciiiaiii attached to tlie coriu and eventually the slimv contents dry uj) and only the dead skin of the roots remains. When the disease begins its attack below the surface of the ground the lower portion of the corm freijuently rots away, causini^ the plant to fall o\ er without ha\ in»^- previously j^ivcn any indication of dis- ease. An examination of the decayed corm shows that only a small part of the ui)p(M* })ortion of the corm, with :i few side roots, remains. The. Fui. 2.—X partly decayed calla corm. latter become less and less iuuium-ous us the disease advances, until at last they are unable to sui)port llu^ weioht of the leaves and iiower stalks. If the conditions for the development of the disease are unfavorable after th(^ corms are affected, the softened spots will dry down, sinking below the surrounding portion of the corm and becoming darker col- ored. In these spots the disease will often remain dormant until the conditions for the development of the organism again become favor- able. In this way the disease is carried over from season to season, and it may be transported long- Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Bureau of Plant Industry, Soils, and Agricultural Engineering. Washington Govt. Print. Off
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