Silicon is a plant beneficial element. It is associated with several positive physiological responses in plants ( Ma, 2004 ), including reduced lodging ( Ma and Yamaji, 2006 ; Savant et al., 1999 ), increased stem diameter ( Kamenidou et al., 2008
Jennifer K. Boldt, James C. Locke and James E. Altland
Jie Li, Scott M. Leisner and Jonathan Frantz
-Colás et al., 2006 ). It is likely that other factors also play a role in Cu homeostasis. The roles and requirements for silicon (Si) in plant biology have been debated for more than 150 years despite numerous reports describing its beneficial properties
Yuan Li, Arend-Jan Both, Christian A. Wyenandt, Edward F. Durner and Joseph R. Heckman
liming agent with potential fungal disease suppression may be of great interest to organic growers. Units Literature cited Belanger, R.R. Benhamou, N. Menzies, J.G. 2003 Cytological evidence of an active role of silicon in wheat resistance to powdery
Shiow Y. Wang and Gene J. Galletta
The effect of silicon (Si) foliar applications on metabolic changes and powdery mildew infection in strawberry plants were determined. Silicon was used in the forms of potassium (K) and sodium (Na) salts. Foliar sprays containing 0, 250, 500, 750, and 1000 ppm of Si were applied. Strawberry plants showed no difference in response to the K or Na salts of Si during the seven weeks of experimental period. Plants treated with potassium and sodium silicate showed reduced severity of powdery mildew, increased chlorophyll content, and increased plant growth. Potassium and sodium silicate treatments also induced metabolic changes such as an increase in citric acid and malic acid levels, and a decrease in fructose, glucose, sucrose, and myoinositol content. The treated tissues also had higher ratios of (18:2 + 18:3)/18:1 in glycolipids and phospholipids and elevated amounts of membrane lipids in leaves and petioles. These results suggest that Si has beneficial effects on strawberry plants and may serve as an alternative to fungicides for controlling powdery mildew.
Victor M. Gallegos-Cedillo, Juan E. Álvaro, Th. Capatos, T. Luan Hachmann, Gilda Carrasco and Miguel Urrestarazu
Strik, 2015 ; Vargas et al., 2015 ). Silicon is not considered an essential element, according to the traditional criteria of Arnon and Stout (1939) , because many plants can complete their cycle in its absence ( Marschner, 2011 ). However, the
Judith Pozo, Miguel Urrestarazu, Isidro Morales, Jessica Sánchez, Milagrosa Santos, Fernando Dianez and Juan E. Álvaro
Silicon is the second-most abundant element in the earth’s crust, and the percentage of Si in the dry matter of plants is between 0.1% and 10%. This quantity is equivalent to those of other macronutrients such as calcium (Ca), magnesium, and
Neil S. Mattson and W. Roland Leatherwood
Silicon (Si) is not considered an essential plant nutrient; however, several plant species demonstrate improved disease resistance, abiotic stress tolerance, and altered morphological traits when Si is present ( Epstein, 1999 ). Soil contains, on
Joseph R. Heckman, Steve Johnston and Win Cowgill
Field experiments were conducted with Cucurbita pepo L. `Howden' pumpkin in 2000 to 2001 to study the effects of silicon (Si) amendment of soil with and without the use of fungicides on yield and powdery mildew suppression. A Quakertown silt loam soil (fine-loamy, mixed, mesic Typic Hapludult) with an initial soil pH of 5.7 was amended with either CaCO3 or CaSiO3 at the rate of 7840 kg·ha-1 of calcium carbonate equivalent. Fungicides were applied on a 7-10 day schedule to half of the plots as a 2 × 2 factorial, beginning when the first powdery mildew lesions were detected in the field. Silicon amendment increased pumpkin yield by 60% in 2000 but Si did not influence yield in 2001. Infection with bacterial leaf spot reduced yield on all plots in 2001. Fungicide applications increased yield only in 2001. In 2000, Si amendment had the effect of delaying foliage senescence but it was not clear if this was the result of an effect of Si on disease activity or crop physiology. In Aug. 2001, Si amendment generally reduced powdery mildew severity, but only at the 10% level of significance. In Sept. 2001, the combination of Si amendment plus fungicide application was more effective in reducing powdery mildew severity than either Si or fungicide alone. Silicon amendment resulted in a 5-fold increase in plant Si concentration. Soil pH measured after harvest in 2001 indicated no significant difference in pH between plots amended with CaCO3 (pH = 6.8) and CaSiO3 (pH = 6.9). In New Jersey, the cost of these liming materials is similar. Thus, the selection of CaSiO3 as a liming material as needed for soil pH correction has the potential benefits of suppressing powdery mildew and increasing pumpkin yield without increasing the cost of production.
Jeffrey H. Gillman, David C. Zlesak and Jason A. Smith
Roses in nursery and landscape settings are frequently damaged by black spot, whose causal agent is the fungus Diplocarpon rosae F.A. Wolf. Potassium silicate was assessed as a media-applied treatment for decreasing the severity and incidence of black spot infection. Roses were treated with 0, 50, 100, or 150 mg·L-1 silicon as potassium silicate incorporated into irrigation water on either a weekly or daily schedule. Five weeks after treatments were initiated, plants were inoculated with D. rosae. Roses began to show visual symptoms of infection §4 days later. Roses that had 150 mg·L-1 silicon applied on a daily schedule had significantly more silicon present in their leaves than other treatments as measured by scanning electron microscopy and energy-dispersive x-ray analysis. In addition, roses that had 100 and 150 mg·L-1 silicon applied on a daily schedule had fewer black spot lesions per leaf and fewer infected leaves than any of the other treatments by the end of the experiment 7 weeks later. Although roses treated with higher levels of silicon on a daily basis fared better than roses in the other treatments, all of the roses were heavily infected with D. rosae by the end of the study. The results reported here indicate that using potassium silicate in irrigation water may be a useful component of a disease management system.
Virginia R. Walter*
A 100 parts per million solution of potassium silicate was added to the nutrient solution of well established, hydroponically grown `Kardinal' rose plants. No significant effects of silicon were determined on post harvest life of the rose flowers harvested over a 3-month period as compared to flowers harvested from control plants grown without the silicon additive. Silicon additive did have a significant positive effect on the length of harvested stems.