Effects of Gibberellic acid and 2,4-Dichlorophenoxy Acetic Acid Spray on Vegetative Growth, Fruit Anatomy and Seed Setting of Tomato (<i>Lycopersicon esculentum Mill.</i>)

Abstract

Article Information The experiment was conducted at Melkassa Agricultural Research Center, Ethiopia with the objective to evaluate the effects of different concentrations and combinations of 2,4-dichlorophenoxyacetic acid (2,4-D) and gibberellic acid (GA3) spray on vegetative and reproductive growth components of tomato. The experiment consists of two tomato varieties, one processing (Roma VF) and one fresh market (Fetan), three levels of 2,4-D (0, 5 and 10 ppm) and four levels of GA3 (0, 10, 15 and 20 ppm) arranged in 2x3x4 factorial combinations, in Randomized Completed Block design with three replications. Data were collected on qualitative parameters (vegetative, reproductive growth and external fruit color) through visual observation, and quantitative parameters (seed number per fruit, seed weight per fruit, fruit shape index and average fruit weight). Qualitative data were analyzed using analysis of variance (ANOVA) by SAS (2002) software and mean separation was carried out by DMRT at 5% probability level. The result indicated that tomato plant treated with 2,4-D intended to have increased stem thickness, decreased leaf size induced epinastic and flower bud abscission in both cultivars while GA3 treatment has no retarded growth and flower bud abscission. Application of 2,4-D has responsible in the development of seedless parthenocarpic fruit with increased size but with unfilled cavities especially at higher concentration. On the other hand, GA3 at lower concentration results in normal fruit and seed development but as its concentration increases it results in the development of more proportion of smaller fruits per plant and formation of blotchy ripening on the fruit. Combined application of the two PGRs at lowers concentrations seems to result in the intermediate effects of both PGRs in single application. In general, concentration of the PGRs used and genetic background of the variety determine the response of tomato growth, fruit setting, seed formation and final marketable fruit size.

The Effect of Plant Growth Regulator on Duku (Lansium domesticum Corr.) Flower for Fruit Formation

“…On the other hand, the lowest total fruit weight per bunch was obtained by P4 treatment at 164.22 g which was significantly different from other treatments (Figure 7 and 8). Gelmesa et al(2010) stated that the implementation of GA3 concentration coud increase the fruit weight in average of 27 % compared to those without GA3 treatment. There was a real difference between 40 ppm concentration and the control of total fruit harvest.…”

Induksi Partenokarpi Pada Tiga Genotipe Tomat Dengan GA3

“…Penurunan jumlah biji pada Gamato 3 dan 'Intan' jauh lebih besar, bahkan pada Gamato 3 penurunan jumlah biji >90% dibandingkan dengan hasil penelitian Gelmesa et al (2013). Gelmesa et al (2013) mendapatkan penurunan jumlah biji pada 'Fetan' dari 114 menjadi 96 biji/buah dan 'Roma' dari 90 menjadi 89 biji/buah pada penyemprotan 10 ppm, bahkan terjadi kenaikan jumlah biji pada 'Fetan' menjadi 126 pada penyemprotan 20 ppm GA 3 .…”

“…Gelmesa et al (2013) mendapatkan penurunan jumlah biji pada 'Fetan' dari 114 menjadi 96 biji/buah dan 'Roma' dari 90 menjadi 89 biji/buah pada penyemprotan 10 ppm, bahkan terjadi kenaikan jumlah biji pada 'Fetan' menjadi 126 pada penyemprotan 20 ppm GA 3 . Penurunan jumlah biji pada penelitian Gelmesa et al (2013) masih jauh dari harapan buah tanpa biji, sebaliknya pada penelitian ini jumlah biji pada penyemprotan 10 ppm atau 20 ppm 3 kali pada Gamato 3 mendekati nol (0). Ini merupakan hasil yang sangat sempurna.…”

“…Aplikasi yang dilakukan berulang (selang tiga hari sekali setelah aplikasi pertama) lebih merangsang peningkatan kandungan giberelin dan auksin sehingga ovul tidak bisa memberikan sinyal pada pollen tube untuk melakukan pembuahan sementara giberelin dan auksin pada ovarium tercukupi pada ambang batas untuk tumbuh menjadibuah. Hal ini yang menyebabkan lebih sedikit ovul yang terbuahi (Gelmesa et al, 2013). Konsentrasi 20 ppm sudah optimal untuk menginduksi partenokarpi Gamato 3, sehingga tidak perlu menggunakan konsentrasi yang lebih tinggi sampai 30 ppm.…”

Yüksek Sıcaklık Koşullarında ve Farklı Su Seviyesinde Gibberellik Asidin (GA3) Sanayi Domatesinde Meyve Tutumuna Etkisi

“…2005;De Jong ve ark. 2009;Gelmesa 2010;Hazra ve Dutta 2010). Gibberelinler gövde uzaması, dormansinin kalkması, endospermdeki depo kaynaklarının harekete geçmesi ve tohum çimlenmesini kontrol etmesi yanında çiçeklenmenin başlatılması, eşey belirlenmesi, meyve oluşumu ve bitkinin vegetatif dönemden generatif döneme geçişi gibi çeşitli fizyolojik olayları etkiler ve düzenler (Taiz ve Zeiger 2008 GA3 uygulamaları bölgede en yüksek sıcaklıkların kaydedildiği Temmuz ayında yapılmıştır.…”