Cutting reproduction is the cheapest and most practical method for plants capable of clonal regeneration. However, the difficulties in adventitious root formation in black mulberry cuttings create a disadvantage for mulberry growers. This study aimed to investigate the effect of IBA and Paclobutrazol applications on the rooting ability of black mulberry hardwood cuttings. The experiment was carried out in the polyethylene greenhouse of Tokat Gaziosmanpaşa University Agricultural Research and Application Center in February 2022. As a material, hardwood cuttings prepared from one-year-old branches of breeding black mulberry trees within the body of the directorate were used. The study was set up in a randomized plot design with 3 replications and 15 cuttings in each replication. In the study, pure water as a control group, 6000 ppm IBA and doses of 1000 ppm, 2000 ppm and 3000 ppm Paclobutrazol respectively were applied to black mulberry wood cuttings separately and together. After the application, the cuttings were planted in perlite medium. The cuttings were kept in the rooting medium for 90 days and then removed; rooting rate, root number, root length and root diameter values were recorded. As a result of the study, the effect of the applications on the root number of the cuttings was not observed while the rooting rate, root length and root diameter parameters were observed. In terms of rooting rate, the best result was obtained from IBA+PBZ 1000 application (40.00%) compared to the control group (0.0%). The highest root length was determined in IBA 6000 application, and the thickest root diameter values were determined in PBZ 1000 application.

Bu çalışmada, dahlia tohumlarına 0, 25, 50 ve 100 ppm dozlarında paclobutrazol uygulaması yapılmıştır. Paclobutrazol ‘un sağladığı olası geciktirici etkilerini ortadan kaldırmak amacıyla fidelerin saksılara dikiminden 1 hafta sonra 0, 100 ve 200 ppm dozlarında yapraktan püskürtülerek GA3 uygulaması yapılmıştır. Çalışma sonunda, fide döneminde, fide boyunda (5,08 cm) ve çimlenme oranında (%80,56) 25 ppm paclobutrazol uygulaması kontrole göre (4,68 cm-%67,59) iyi sonuçlar göstermiştir. Paclobutrazol dozları arttıkça belirtilen parametrelerde düşüşler yaşanmıştır. İkinci aşamada ise, paclobutrazol uygulamaları yapılmamış olup tohumdan uygulanan paclobutrazol ile yetiştirilen fidelere GA3 uygulaması yapılmıştır. Paclobutrazol uygulamaları yapılan ancak GA3 uygulanması bulunmayan fidelerin bitki gelişimi açısından istatistiksel farklılıklar çıkmamasına rağmen 50 ppm paclobutrazol uygulaması bitki boyu (47,87 cm) ve bitki gövde çapında (6,55 mm), 0 ppm paclobutrazol uygulaması kök yaş ağırlığı (7,02 g) ve 50 ppm paclobutrazol uygulaması ise kök uzunluğunda (22,70 cm) en iyi sonuçları göstermiştir. Farklı konsantrasyonlardaki GA3 uygulamalarında ise 100 ppm GA3 uygulaması diğer uygulamalara kıyasla bitki gelişimi açısından en iyi sonuçları vermiştir. Paclobutrazol ve GA3 uygulamalarının kombine edilmesiyle bitki gelişiminde ağırlıklı olarak 50 ppm paclobutrazol ve 100 ppm GA3 uygulamaları daha etkili olmuştur. Fidenin büyüme ve çiçeklenme açısından boy kontrolünde 25 ppm paclobutrazol kullanılabileceği, kaliteli bitki gelişimi ve olası geciktirici etkileri ortadan kaldırmak için 100 ppm GA3 uygulanması gerektiği sonucuna varılmıştır.

Paclobutrazol (PBZ) is a growth regulator that widely used in horticulture and in the tomato seedling growth to compact the shoots, increase the stem diameter and, root biomass, allowing more tolerance of the seedlings against adverse weather conditions. The objective of this work was to evaluate the rates of paclobutrazol (0, 4, 7, 10 and 13 mg L-1) applied 15 days after sowing by foliar spray on the growth, chemical composition and xylem vessel number of tomato seedlings cultivated in two periods. The PBZ regardless of the application rate reduced the height of tomato seedlings in both growth periods. The basal stem diameter and leaf area were increased with 13 mg L-1 of PBZ. The lignin percentage also increased with 10 and 13 mg L-1 of PBZ as compared to control for both periods. The number of xylem vessel was not affected by PBZ application on the seedlings in the first period. PBZ application at rates of 7 and 10 mg L-1 increased the xylem vessel number in the second period. In general, the application of 13 mg L-1 of PBZ generated seedling more robust to overcome climate adversities.