POTASH IN PLANT METABOLISM Deficiency Symptoms as Indicators of the Role of Pottassium

Timing and magnitude of potassium supply determines the location of potassium deficiency symptoms

“…The net export of K from the lower leaves in K0 from seedling stage to resettling stage was reduced by 26%, while the net import of K by the upper leaves almost tripled, and other parts remained generally unchanged. The reduction in net K export from the lower leaves in K0 from seedling stage to resettling stage, while the net import of K by the upper leaves increased, and other organs remained generally unchanged was consistent with the classical K deficiency theory (Hoffer, 1938, Marschner, 2011. Tobacco plants without K through the entire growth phase were unable to meet their K requirements, together with the increased net K export from the lower leaves in the early stage, the net export from the middle and upper leaves and the reduced K accumulation in the later stage, made the symptom follow the classical K deficiency symptom and development trend.…”

“…When K supply is insufficient, it can be quickly transferred from older leaves at the bottom of the plant to the upper part of the plant through the phloem to ensure normal growth of young organs (Hoffer, 1938, Marschner, 2011. Therefore, K deficiency symptoms generally occur in the middle and late stages of plant growth (Lu, 2003), and first appear in the lower leaves (Hoffer, 1938). When K deficiency is mild, symptoms initiate at the margins and tips of the lower older leaves.…”

Starch Formation in Tobacco Plants Deficient in Potassium1

“…GASSNER alid GOEZE (6) state that assilmilation is poorer with lack of balance of these two elements thani it is with the samiie deoree of deficielncy of both elemenits. HOFFER (10) an1d PHILLIPS, SMIITH, and HEPLER (14) have reviewed the pertillenit literature o01 this phase of the problem. The latter authors foulnd that low potassiulil supply wihile there is a high level of niitrogen depresses growth anid reduces the amounit of stareh ill stems, but that with a low ilitrogeni supply "potassiln deficienicy actuallv improves growth slightly" anid results inl more starch ill the stemis.…”

Minerals Solubilizing Microbes for Agricultural Sustainability

“…The deficiency of minerals (N, P, K, Mn, K, Zn, Fe, Mg, and S) in plant can cause various problems like stunt the plant growth by inhibiting the root system and flowering, shortening of internodes, lowering the yield of the crops, photosynthesis reduction, blackening of some tubers like potato, and scorching of all small grains, chlorosis and spotted refers to a surface that has colored spots (anthocyanin develops). Therefore, as the severity of the deficiency develops, potassium deficiency symptoms usually begin on the lower leaves of the plant and move upward [5]..…”