Effects of seaweed application on ungrafted seedling development in pistachio (Pistacia vera l.cv.siit)

This study was carried out to determine the effects of some biostimulant applications (seaweed (DY), amino acid (AA), alginic acid (ALA) on growth and physiological responses in pistachio (Pistacia vera L. cv. Siirt) seedlings. Plant height, stem diameter, leaf chlorophyll content and enzyme activities (proline, catalase, polyphenol oxidase) were evaluated in seedlings. At the beginning of the experiment, height values were similar among the groups (32,3–34,5 cm). At the end of the application, the mean heights were found to be 55,6 cm and DY: 54,0 cm, higher than the control group (49,6 cm); similarly, the highest value for stem diameter was determined as 7,8 mm in ALA and 6,9 mm in control. According to paired t-test, increases in length and diameter were significant in all groups (p=0,001); the highest height increase was determined as 20,03 cm in DY. Physiological Proline levels in the indicators were higher in the control (45,2 µmol/gFW) and lower in the treatments; catalase activity reached the highest value in ALA with 604,5 U/g/dk, and polyphenol oxidase activity was found to be highest in AA with 900,4 U/g/dk. In conclusion, seaweed extract, and especially alginic acid application, supported seedling development; changes in enzyme responses indicated that these applications may also have an effect on stress and defense mechanisms.