Karadeniz Zirvesi 5. Uluslararası Uygulamalı Bilimler Kongresi, Rize, Türkiye, 19 - 21 Şubat 2021, ss.176-186
Leonardite's including high content of humic acid ranging from 30 to 80% may make it useful
as a soil reclamation and improvement. Marigold (Tagetes patula L.) is a ornamental plant
that is not very selective in terms of climate and soil and is grown in many countries of the
world. The experiment were conducted to evaluate the vegetative growth responses of
marigold obtained by the addition of different levels of raw leonardite to the clayey-loamy
soil growing medium. Also, it was conducted to examine the effects of leonardite on growth
of marigold and to provide information about potential optimal and toxic levels. Tagetes
patula L. cv. "Nana" is used as plant material. In the experiment, different levels of raw
leonardite were prepared by adding 1/64 leonardite (v/v) (T1), 1/32 leonardite (T2), 1/16
leonardite (T3), 1/8 leonardite (T4), 1/4 leonardite (T5) to soil medium and control groups
were prepared by adding commercial humic acid to soil medium (30 ml l-1
) (T6) and using
only soil medium (T7). In the experiment, T1 application was increased in marigold shoot
growth compared with plants produced with only soil. It was observed that there was no
statistical difference between T7 and T6 applications with T1 application in terms of
parameters number of leaf (29 number plant-1
), the number of side branches (15.67 number
plant-1
), shoot fresh weight (35.91 g), fresh (18.91 g) and dry weight (1.36 g) of root and stem
diameter (6.43 mm). The highest organic matter ratio was determined in T6 application; other
applications were in the same statistical group in terms of organic matter ratio. Total nitrogen,
P and K amounts were determined at the highest rate in T4 and T5 applications. The obtained
results showed that beneficial effect had been taken from low levels of natural leonardite in
marigold.