RÊGO, P. L.; http://lattes.cnpq.br/4200325367154514; RÊGO, Pietro Lopes.
Resumo:
The Brazilian citrus industry is a highly organized and competitive sector, being one
of the most outstanding activities of the country's agribusiness. As it encompasses a large
number of fruit plants of socioeconomic importance, the success of the production chain
depends a lot on technification and technologies adapted to the production regions. The
preference for rootstocks that favor changes to the canopy variety in terms of growth,
production and fruit quality, has been studied by several research centers. Although numerous
rootstocks and citrus canopies are available in germplasm banks in Brazil, there are no studies
that indicate alternative varieties for cultivation in the Cerrado of Tocantins. Knowledge about
highly adaptable genotypes and combinations between these genotypes is important not only
for the safety of the production chain, but it is also important for increasing productivity and
fruit quality. The aim of this study was to select combinations of crowns / rootstocks that best
adapt to the conditions of Tocantins by assessing growth and physiological responses to
different levels of water availability as a function of ETc. The work was carried out in the
experimental area of the Federal Institute of Education, Science and Technology of Tocantins,
Campus Dianópolis. Located in the southeastern region of the state of Tocantins, municipality
of Dianópolis. His conduct was guided by the study of two citrus canopy varieties, grafted
under different rootstocks and receiving 5 levels of water supplementation. The citrus canopy
varieties (C) were, C2 - 'Tahiti' acid lime [Citrus latifolia (Yu. Tanaka) Tanaka], selection
EMBRAPA 2001 and C1 - orange 'Pêra' [Citrus sinensis (L.) Osbeck]. All variables were
subjected to analysis of variance, Tukey-type averages test at a level of 5% probability, and
regression analysis with treatment unfolding within each crown / rootstock combination. The
results showed that the plants grafted with the canopy acid lime variety 'Tahiti' showed higher
growth rates than those grafted with the orange cane variety 'Pêra' in all evaluated seasons.
The citrandarin rootstock 'Riverside' provided the 'Tahiti' acidic canopy variety with the most
appropriate physiological behavior, thus obtaining the greatest development within the growth
variables analyzed. The orange crown variety ‘Pêra’, obtained the best results, both for
physiological parameters and for development, through the Cravo Santa Cruz genotype. These
canopy / rootstock combinations were the most adapted to local conditions, being the most
prominent in development in the first two years of cultivation. Aiming at the efficient use of
water, water availability in 75% of the ETc is recommended for the cultivation of these
canopy / rootstock combinations in edaphoclimatic conditions in the Tocantins' cerrado,
certain that the plants submitted to this water regime did not differ in their majority. of the
plants that received water availability at 100% of the ETc.