Reguladores vegetais no florescimento e produção da mangueira no semiárido

Abstract

The mango-culture is an important agricultural activity in the Brazil because this production attends national and international marketing. The main difficult in the culture management is the production seasonality caused to alternate flowering that can be controlled by flowering induction technology with use of plant growth regulators applied to soil. However, the product persistence in the soil can be compromise the culture and the environment which stimulates the search for alternatives of plant growth regulators application technologies as well as understand the morphological and anatomical alterations caused by flowering induction. The objective of this work was to evaluate the effect of different plant growth regulators (uniconazole, chlormequat chloride, ethil-trinexapac) applied on foliar pulverization compared to the application of one regulator (pachlobutrazol) on soil on floral differentiation, production and fruit quality of mango ‘Palmer’ and ‘Kent’. Additionally, this work aimed to evaluate the morphological and anatomical alterations on ‘Palmer’ mango during flowering differentiation.As results of the first object, we observed the efficiency of the reduction of the vegetative growth in ‘Palmer’, resulting on flowering and fructification. The application of pachlobutrazol and uniconazole promotes better conditions of flowering the other treatments, resulting in major productivity of this treatments and the chlormequatchloride treatment. Fruit quality was little influenced by plant growth regulators compared to control, suggesting the use of foliar spray of chlormequat chloride or uniconazole in the substitution to pachlobutrazolapplicated on soil. On ‘Kent’ mango, just pachlobutrazol and uniconazole regulate the vegetative growth, inducing the flowering. The application of pachlobutrazol induced higher productivity than uniconazole, suggesting studies of the association of application of reduced dosage of pachlobutrazol on soil and foliar spray of uniconazole.On semiarid conditions, the flowering induction using pachlobutrazol was associated to cellular expansion restriction and the phenolics compounds accumulation on stem apex. It was observed the calcium oxalate and lipophilics compounds accumulation on mesophyll leaf on ‘Palmer’ mango. The flowering development occurs on 13 days after the floral induction, when the axis of the inflorescence and the floral parts was formed. Under the conditions, the flowering occurs over 32 days between floral induction and the anthesis, making 8 development stages. It is important identify, understand and clearly describe the morphological and anatomical alterations occurs during the floral induction and floral development so that the data can be used for decision making, as well as the development floral inductions technologies more adapted to the semiarid conditions.