Effect of Silicon and/ or NPK Treatments on Growth, Flowering and Corm Production in Gladiolus

 APOT EXPERIMENT was consummated in the open at the ……..experimental farm of Hort. Res. Inst., ARC, Giza, Egypt during 2011/2012 and 2012/2013 winter seasons. The effect of silicon in the form of diatomite applied as foliar spray or soil drench at the rates of 1,2 and 4 g/ l and NPK (2:1:2) mixture at 2 g /pot as soil drench on Gladiolus grandiflorus Andrews cv. Flora Red plant production. The effect of combined treatments between Si at 1, 2 and 4 g/l and NPK mixture at 2 g/pot was also studied. The control plants received no fertilization.
The results of this experiment have shown that all treatments used in this study caused a significant increment in the means of all vegetative growth parameters, flowering stalk length and number of florets/spike, and decreased the number of days to flowering. A similar trend was also obtained regarding the mean number of corms and cormels/plant, diameter of corm and cormel, fresh and dry weight of corm and cormel, as well as leaf contents of Si, chlorophyll a, b, carotenoids, N, P and K. The results also indicated that means of all previous measurements increased progressively with increasing silicon level regardless of application method (foliar or drench). However, soil drench application method gave better results than foliar spray. Moreover, the combining between Si and NPK mixture induced an additional improvement in the means of various a forenamed characters in the two seasons. The combining between Si at 4 g/l and NPK mixture at 2 g/pot gave the utmost high values compared to the other sole and combined treatments.
Hence, it can be advised to treat gladiolus cv. ʺFlora Redʺ plants cultivated in pots with silicon in the form of diatomite powder at 4 g/l plus NPK mixture (2:1:2) at 2 g/pot applied as soil drench.