Growth and biomass production in potato grown in the hot tropics as influenced by paclobutrazol

Abstract

Two similar field trials were carried out during 2003 in a hot tropical region of eastern Ethiopia to investigate the effect of leaf and soil applied paclobutrazol on the growth, dry matter production and assimilate partitioning in potato. A month after planting paclobutrazol was applied as a foliar spray or soil drench at rates of 0, 2, 3, and 4 kg a.i. paclobutrazol ha À1 . Plants were sampled during treatment application and subsequently 2, 4, 6 and 8 weeks after treatment application. The data was analyzed using standard growth analyses techniques. None of the growth parameters studied was affected by the method of paclobutrazol application. Paclobutrazol decreased leaf area index, crop growth rate, and total biomass production, and increased specific leaf weight, tuber growth rate, net assimilation rate, and partitioning coefficient of potato. At all harvesting stages, paclobutrazol reduced the partitioning of assimilate to the leaves, stems, and roots and stolons and increased allocation to the tubers. Although paclobutrazol decreased the total biomass production it improved tuber yield by partitioning more assimilates to the tubers. Paclobutrazol improved the productivity of potato under tropical conditions by redirecting assimilate allocation to the tubers.

Aplicación periódica de bajas concentraciones de paclobutrazol y ácido salicílico en papa en invernadero

“…There are contradictory statements regarding paclobutrazol, if it favors tuber Tekalign et al (2005) mention that may cause decreased performance, Flores et al (2011) confirmed to mention that some of the concentrations studied from 200 to 250 mg L -1 decrease biomass tubercle, while at concentrations of 150 mg L -1 no significant difference with the control without paclobutrazol in this sense.…”

“…Existen afirmaciones contradictorias en relación respecto al Paclobutrazol, si favorece la tuberización, Tekalign et al (2005), mencionan que puede provocar disminución de rendimiento, Flores et al (2011) lo confirman al mencionar que algunas de las concentraciones en estudio de 200 a 250 mg L -1 disminuyen la biomasa de tubérculo, mientras que a concentraciones de 150 mg L -1 no hay diferencia significativa con el testigo sin Paclobutrazol en este sentido.…”

“…Several growth inhibitors have been used as antagonistic agents gibberellins in non-inductive conditions tuberisation (high temperature and long photoperiods), such as: tetcyclasis, cycocel, paclobutrazol, uniconazole, alar, ancymidol and daminozide, some of the which increase the formation of tubers in conditions in vitro and greenhouse (López et al, 1998;Rodríguez et al, 2006;Tekalign et al, 2005;Flores et al, 2011).…”

“…However, Flores (2011) mention that with 150 mg L -1 paclobutrazol or 20 mg L -1 uniconazole, the plant height is reduced without affecting the number of tubers and biomass. However, there are also studies where there may be an adverse effect by applying paclobutrazol, mentioned which can reduce the biomass of the entire plant (Tekalign et al, 2005) and even the performance of minitubers (Hughes and Keith, 2003).…”

“…Sin embargo, Flores (2011) mencionan que con 150 mg L -1 de paclobutrazol o 20 mg L -1 de uniconazol, se redujo la altura de las plantas sin afectar el número y biomasa de tubérculos. Sin embargo, también existen estudios donde puede existir un efecto negativo por la aplicación de paclobutrazol, se menciona que puede reducir la biomasa de la planta completa (Tekalign et al, 2005) e incluso el rendimiento de minitubérculos (Hughes y Keith, 2003).…”