Um dos fatores que oneram os custos de produ??o de mudas de caf? ? a aduba??o. O uso
de fertilizantes de libera??o controlada ? uma alternativa para produ??o comercial de
mudas produzidas em tubetes com substrato comercial com baixa CTC. Assim, objetivou-se
avaliar o crescimento e respostas fisiol?gicas de mudas de caf? ar?bica produzidas em
tubetes e submetidas a diferentes doses e fontes de f?sforo. O experimento foi conduzido
em casa de vegeta??o, em delineamento de blocos ao acaso, com onze tratamentos e
quatro repeti??es, e com tr?s plantas por parcela. Utilizou-se substrato comercial e tubetes
de 100 mL, previamente lavado e a cultivar Mundo Novo IAC 379, de porte alto. Os
tratamentos constitu?ram nas aduba??es fosfatadas com Osmocote, organomineral
peletizado e farelado nas doses de 4, 8 e 12 g/dm?, MAP, MAP revestido, Superfosfato
Simples + Ureia e testemunha (sem aduba??o). Ap?s 180 dias do transplantio avaliou-se
o crescimento, os ?ndices de qualidade e fisiol?gicos das mudas, o teor de f?sforo foliar
e de clorofila a e b, clorofila total e teor de f?sforo lixiviado do substrato. Os maiores
teores de mat?ria seca, rela??o parte a?rea/sistema radicular e ?ndice de qualidade de
Dickson foram observados para a aduba??o com o organomineral na dose de 4 g/dm? de
P2O5, o osmocote e o MAP revestido. Em rela??o as respostas fisiol?gicas, a aduba??o
com o organomineral na dose de 4 g/dm? de P2O5, o osmocote e o MAP revestido foram
capazes de alocar maior quantidade de fotoassimilados para as ra?zes, al?m de reduzir as
perdas de f?sforo por lixivia??o. De acordo com as equa??es ajustadas em fun??o das
doses do organomineral peletizado e farelado, a dose que maximiza o crescimento e a
qualidade das mudas de caf? ? de aproximadamente 6 g/dm? de P2O5. Diante disso,
conclui-se que as aduba??es utilizando organomineral peletizado e farelado e o MAP
revestido obtiveram resultados semelhantes quando comparado ao Osmocote,
viabilizando o uso para produ??o de mudas de caf? em tubetes.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2019.One of the factors that burden coffee seedling production costs is fertilization. The use of
controlled release fertilizers is an alternative for commercial production of seedlings
produced in low CTC commercial substrate tubes. Thus, the objective was to evaluate the
growth and physiological responses of arabica coffee seedlings grown in tubes and
submitted to different doses and sources of phosphorus. The experiment was carried out
in a greenhouse in a randomized block design with eleven treatments and four replications
and three plants per plot. Commercial substrate and previously washed 100 ml tubes were
used and the cultivar Mundo Novo IAC 379 was large. The treatments consisted of
phosphate fertilizers with Osmocote, pelleted organomineral and bran in doses of 4, 8 and
12 g / dm?, MAP, coated MAP, Simple Superphosphate + Urea and control (without
fertilization). After 180 days of transplantation, seedling growth, quality and
physiological indices, leaf phosphorus and chlorophyll a and b content, total chlorophyll
and substrate leached phosphorus content were evaluated. The highest contents of dry
matter, shoot / root system ratio and Dickson quality index were observed for fertilization
with organomineral at a dose of 4 g / dm? of P2O5, osmocote and coated MAP. Regarding
the physiological responses, the fertilization with the organomineral at a dose of 4 g / dm?
of P2O5, the osmocote and the coated MAP were able to allocate larger amount of
photoassimilates to the roots, besides reducing the phosphorus losses by leaching.
According to the equations adjusted for pelleted and branched organomineral doses, the
dose that maximizes growth and quality of coffee seedlings is approximately 6 g / dm? of
P2O5. Therefore, it can be concluded that fertilization using pelleted and branched
organomineral and coated MAP obtained similar results when compared to Osmocote,
making it possible to use coffee seedlings in tubes
