The results obtained in this studies are summarized as follows : 1) The presence of boron in dilute concentration is essential to continue the growth of “Kenaf" plants in chemically pure water culture solution. 2) For the life cycles of Kenaf plants, boron above 0.025p.p.m. must be contained in the nutrient culture solutions renewing them once a week. 3) Supplying the boron to boron-starved plants soon after the boron deficiency symptoms appeared, they enable to reestablish their ordinary growth in their life cycles. 4) Kenaf plants grown in nutrient solution free from boron develop the following symptoms of boron deficiency : (a) poor development, roughness and discoloration of root system, (b) chlorosis, thickening and wrinkling of the leaves, (C) appearance of small and short fissure(or split)like lines and scabs on the surface of petioles and stems,(d) petioles, sometimes also stems, bend, (e)characteristic brittleness of the stems and leaves,(f) cessation of the terminal growth of the stem. 5) Bending phenomena of petiole is most clear, definite and easy visible symptom of boron deficiency.
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