Combinação do paclobutrazol, sulfato de potássio e etefon na indução floral da mangueira cv. Tommy Atkins

Amongst the techniques used for the regulation of the vegetative growth of mango trees withthe purpose in floral induction, is common the arranged use of the substances Paclobutrazol,Potassium Sulfate and Ethephon. Under conditions of semi-arid tropic the precipitated techniquehas persuaded an abundant flower induction, however has produced inconsistent effects in theconditions of warm and rainy climate. With the purpose to study that combination in the growth eflowering of mango trees, variety Tommy Atkins, it was experimented in the mesorgion of TeresinaCity, State of Piauí, under conditions of humid tropic, using an experimental design of randomizedcomplete blocks, with an factorial arrangement 4 x 3: four Paclobutrazol doses (zero; 0.7; 1.0 and 1.3g of a.i. m-1 of diameter tree canopy) and three practices that combined applications of PotassiumSulfate (2%), Ethephon (240 ppm) on three periods of floral induction, 90, 105 and 120 days, to thestart of application of dormancy-breaking, which was counted from the Paclobutrazol application.Plants untreated produced only vegetative branches and the various products and periods ofapplications combinations tested showed low rates flowering and high rates of dormant buds.Dentre as técnicas utilizadas para a regulação do crescimento vegetativo da mangueira visando à indução floral, é comum o uso combinado de paclobutrazol, sulfato de potássio e etefon. Nas condições tropicais semi-áridas a referida técnica tem induzido florações profusas e antecipadas, mas tem produzido efeitos inconsistentes nas condições de clima quente e chuvoso. Com o objetivo de estudar essa combinação no crescimento e florescimento de mangueiras da variedade Tommy Atkins, sob condições de trópico sub-úmido, na mesorregião de Teresina, Piauí, realizou-se o presente experimento. Utilizou-se o delineamento experimental de blocos casualizados, no arranjo fatorial 4 x 3, quatro doses de paclobutrazol (zero; 0,7; 1,0 e 1,3 g do i.a. m-1 de diâmetro de copa) e práticas que combinaram aplicações de sulfato de potássio (2%) e etefon (240 ppm) em três épocas (90, 105 e 120 dias) de início da quebra de dormência das gemas a partir da aplicação do paclobutrazol, com cinco repetições. As plantas não tratadas emitiram apenas ramos vegetativos e as diversas combinações de produtos e épocas de aplicação testadas apresentaram baixos percentuais de florescimento e elevados percentuais de gemas dormentes.Combination of paclobutrazol, potassium sulfate and Ethephon on floralinduction of mango cv. Tommy AtkinsAbstractAmongst the techniques used for the regulation of the vegetative growth of mango trees withthe purpose in floral induction, is common the arranged use of the substances Paclobutrazol,Potassium Sulfate and Ethephon. Under conditions of semi-arid tropic the precipitated techniquehas persuaded an abundant flower induction, however has produced inconsistent effects in theconditions of warm and rainy climate. With the purpose to study that combination in the growth eflowering of mango trees, variety Tommy Atkins, it was experimented in the mesorgion of TeresinaCity, State of Piauí, under conditions of humid tropic, using an experimental design of randomizedcomplete blocks, with an factorial arrangement 4 x 3: four Paclobutrazol doses (zero; 0.7; 1.0 and 1.3g of a.i. m-1 of diameter tree canopy) and three practices that combined applications of PotassiumSulfate (2%), Ethephon (240 ppm) on three periods of floral induction, 90, 105 and 120 days, to thestart of application of dormancy-breaking, which was counted from the Paclobutrazol application.Plants untreated produced only vegetative branches and the various products and periods ofapplications combinations tested showed low rates flowering and high rates of dormant buds.