Silicon deficiency of tomato plant
Tomato plants were solution cultured with and without silicon, and Si deficiency symptoms were observed in the first bud flowering stage when the tomato plants had been cultured in a silicon-free solution; however, normal growth was observed in a solution with 100 ppm SiO_2. To induce Si deficiency symptoms, it is necessary to culture the plant in a silicon-free solution under favorable conditions for the growth of tomato plant. Select the most suitable cultivar for the environmental conditions. Optimum temperatures with differences for day and night, high light intensity, sufficient aeration, and low planting density are key points in the development of a Si deficiency. Symptoms of Si deficiency may be summarized as follows : 1) The deficiency symptoms appear after the first bud flowering stage. 2) The leaflets of the new leaves showed malformations such as curving to the outside, warping, hardening, and sometimes thickening. 3) The growing point at the top was retarded in development, but did not die back as with boron deficiency. 4) The leaves were slightly yellowed, and necrotic spots appeared on the lower leaves; these spots generally spread upwards to the upper leaves. 5) In severe cases, the plant began to dry up from the lower leaves upward. 6) The silicon-free cultured plants can bloom, but often fail to pollinate; often they bear malformed fruit or no fruit. 7) The appearance (color, shape etc.) of the roots are normal. 8) Silicon-free plants already showing deficiency symptoms developed normal shoots after silicon was supplied, while silicon applied plants growing normally, developed deficiency symptoms when they were given silicon-free treatment in the flowering stage. 9) Si deficiency symptoms increased by long-day treatment and decreased by short-day treatment. From these results, we conclude that silicon has an effect on the reproductive growth of the tomato plant.
- Soil Sci. Plant Nutr.
Soil Sci. Plant Nutr. 24, 175-185, 1978