Paclobutrazol suppressed vegetative growth and improved yield as well as fruit quality of ‘Tommy Atkins’ mango(Mangifera indica)in Ethiopia

Abstract

The effects of paclobutrazol on the vegetative growth, reproductive development, total nonstructural carbohydrate of the shoots, and nutrient mobilisation to the leaves of 'Tommy Atkins' mango (Mangifera indica) trees grown in the Rift Valley of Ethiopia were evaluated during the 2002/03 season. The trees used were characterised by excessive vegetative growth, erratic flowering, and fruiting with declining productivity that validated the evaluation of paclobutrazol. Uniform trees were selected for a randomised complete block design experiment with two methods (soil and spraying) and four rates of paclobutrazol (0, 2.75, 5.50, 8.25 g a.i. per tree) in factorial combinations. There were three blocks and three trees per plot for each treatment. The results showed that application of paclobutrazol at rates of 5.50 and 8.25 g a.i. per tree both as a soil drench and spray applications were effective in suppressing vegetative growth compared with the control. Consequently, the trees from these treatments had higher total non-structural carbohydrate in their shoots before flowering. Compared with the control, trees treated with paclobutrazol had higher results for percentages of shoots flowering, number of panicles produced, percentages of hermaphrodite flowers, yield as well as quality of the fruit. Applications of paclobutrazol did not affect the leaf macronutrient content levels analysed (N, P, K, and Ca), and with the exception of manganese, the micronutrient (Cu, Zn, and Fe) levels of the treated tree's leaves were significantly higher than the control.

Reproductive physiology of mango

“…Paclobutrazol, sold in the tropics under the trade name Cultar (Syngenta Corp., also available from several Chinese manufacturers and distributors), reduces the time in rest necessary to allow floral induction during warm temperature conditions by approximately one month (Davenport, 2003), thus increasing the potential to produce reproductive shoots in younger stems upon shoot initiation. Application of paclobutrazol or uniconazole [Sumitomo Chemical Co. (international) or Valent Corp. (USA)], triazole compounds that inhibit synthesis of kaurene oxidase in the gibberellin-synthesis pathway (Dalziel and Lawrence, 1984;Rademacher, 1991), stimulates production of flowering shoots during these weakly inductive conditions Gunjate, 1991, 1993;Tongumpai et al, 1991;Voon et al, 1991;Nartvaranant et al, 2000;Yeshitela et al, 2004). Thus, field application of paclobutrazol to trees bearing one-month-old mango stems produced inflorescences from those stems when bud break was initiated three months later by a foliar application of KNO 3 (Davenport, 2003).…”

Influence of paclobutrazol on growth, yield and quality of mango

“…Paclobutrazol exhibits the pronounced effect on increasing the parameters like ascorbic acid, total sugar, reducing sugar and TSS, except for acidity in fruits of Alphonso mangoes at 2 SARKER AND RAHIM Coimbatore, India (Vijayalakshmi and Srinivasan, 2000). Mango trees treated with paclobutrazol had higher results for number of panicles produced, yield as well as quality of fruit compared to control (Yeshitela et al, 2004). Information regarding regulation of flowering and harvesting time, increasing yield and quality of mango using paclobutrazol is little or nil in Bangladesh.…”

Peliculização de sementes de tomate associada ao paclobutrazol

“…A aplicação de paclobutrazol por meio de pulverizações foliares e/ou molhamento de substrato pode ocasionar a acumulação de resíduos em partes vegetais comercializáveis, principalmente em frutos (Yeshitela et al, 2004). Quando a veiculação do paclobutrazol ocorre por meio do tratamento de sementes, verifica-se a adequação satisfatória na altura de plântulas e os teores residuais em frutos não ultrapassam os níveis de segurança estabelecidos por agências internacionais como a United States Environmental Protection Agency US-EPA (Magnitsky et al, 2006b).…”