Compendium of Potato Diseases - (PDF, 101 mb) - USAID

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of the "Katahdin" potato plant. Am. Potato J. 51:345-354.
SOI.TANPOUR. P.N.,J.O. REUSS, J. G.WAIKER, R. D. 1EIL. ..
W. IlNDSAY. J. C. HANSEN. and A. .1.REIYEA. 1970. Zinc
experiments on potatoes in the San L.uis Valley of Colorado. Am.
Potato J. 47:435-443.
Manganese
Deficiency symptoms develop on the upper parts of the plant
as loss in luster. Light green interveinal chlorotic tissue later
becomes yellow to white (Plate 10). lower leaves are least
affected, but leaves nearshoot tips often roll upward. When the
deficiency issevere, brown necrotic spots develop along the vcins
of younger leaves.
Mn deficiency is possibly the most common micronutrient
problem for potatoes grown on muck, sandy muck, or
depressional soils in central and eastern coastal areas of the
United States. It is reported on calcareous or excessively limed
soils of high pH. Mn should be applied when leaf tissue tests
show less than 25 ppm Mn. Manganese sulfate applied to foliage
at the rate of 1.1-2.2 kg of Mn per hectare ( - 2 !b A)is useful to
correct the deficiency. Certain fungicides containing Mn also
alleviate the condition.
Mn toxicity, to which the potato is especially, sensitive, has
been called stem streak, stem streal necrosis, land streak, or
stem break. Cultivars differ in sensitivity or tolerance. Early
season Mn toxicity develops slowly: initial symptoms are
necrotic flecking of stem and petioles (Fig. 32A). Sometimes leaf
flecks develop into elongate, dark brown pitted streaks. This
occurs first at the lower stem and progresses upward, being most
severe at petiole bases and developing on the petioles (Fig.
32Band C). Necrosis becomesevident at400 ppm in lowerleaves,
It appears first on the epidermis and later extends deep into
the cortex, ray tissue, and pith. The Mn content in leaf
tissue and the symptom severity increase rapidly after the
blossom stage. Affected parts become necrotic and dark brown
and are extremely brittle. The terminal bud may eventually die.
The plant remains stunted and may die early. In solution
culture, 25 ppm Mn reduces growth.
Leaves lose their typical bright green color and show a pale,
yellow-green interveinal chlorosis that becomes progressively
severe, often with marginal necrosis. Eventually the leaves dry,
hang down, and break off as the petiole becomes brittle.
Inverveinal necrosis may precede leaf death.
Symptoms have not been described in tubers except that yield
may be severely impaired.
Neither pH alone, Ca deficiency, Mg deficiency, nor Al
toxicity cause stem streak necrosis. Stem necrosis by rugose
mosaic virus may be superficially somewhat similar.
Symptoms of Verticillium wilt are enhanced in pot culture in
soil with a high level of Mn.
Mn icre:!es in soluHlity as the soil becomes more acid;
toxicity occurs on light acid soils at pH 5.0 and below. Additions
of lime to raise soil above pH 5.0 are usually effective in avoiding
injury. Both symptom severity and Mn content of leaves are
reduced with Ca lime soil treatment and increased with chloride
or sulfate fertilizers.
Selected References
BERGER, K. C., and G.C. GERLOFF. 1947. Stem streak necrosis of
potatoes in relation to soil acidity. Am. Potato J. 24:156-162.
CHENG. B.T.. and G.J.OUEILETTE. 1968. Effect of variousanions
on manganese toxicity in Solaoun: tuberosum. Can. J. Soil Sci.
48:109-115.
I.ANGILI.E. A. R.. and R. 1. BATTEESE, Jr. 1974. Influence of
manganese concentration
elemental
in nutrient
content
solution
of the "Katahdin"
on the growth
potato
and
plant. Can.
54:375-381.
J.Plant Sci.
ROBINSON, D. B.. G. D. EASTONand R. H. IARSON. 1960. Some
common stem streaks of potato. Am. Potato J. 37:67-72.
WHITE, R. P.. E. C.DOLL, and J. R. MELTON. 1970. Growth and
manganese uptake by potatoes as related to liming and acidity of
fertilizer bands. Soil Sci. Soc. Am. Proc. 34:268-271.
WHITE. R. P., A. R.SIETING. and E. C. DOLL. 1972. Manganese
fertilization of potatoes in Presque Isle County. Mich. State Univ.
Agric. Exp. Stn. Res. Rep. 179. 2 pp.
(Prepared b' W. J. Hooker with assistance from L. M.
Walsh on nitrogen and sulfur sections and from R. E.
Lucas on magnesium and manganese sections)