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Previous issue date: 2007-01-19 / A study was conducted at the Integrated System of Agroecological Production (a Research
Farm, located in Serop?dica, State of Rio de Janeiro), to evaluate the cycle development and
the agronomic performance of papaya under organic management, comparing two ways of
growing the plant (with and without trunk bifurcation) in three types of protected
environment. Papaya seedlings, cv. Baixinho de Santa Am?lia ("Solo" group), were
transplanted to contiguous structures as follows: (a) greenhouse (plastic covering), (b)
shadowed greenhouse ('sombrite' net - 30%, over the plastic sheet), and (c) screenhouse
('sombrite' net - 30%, exclusively), side-by-side to an area for papaya cultivation under
natural conditions. The greenhouse lateral and frontal parts were protected with anti-aphid
screen. In these four treatments, 50% of the hermaphrodite plants were submitted to an
incision of the apical bud, soon after sex determination. For a 12 months period of cultivation:
temperature, relative air humidity and light radiation were measured in each environment.
Regarding to development of papaya: plant height, basal trunk diameter, number of leaves per
plant, foliar area, and periods of time to complete phases of the cycle were determined. A
study of floral biology and of fruits characteristics also corried out. Cultural practices agreed
with technical rules of organic agriculture. For comparisons among differents environments,
the jointly experiment analysis" method was adopted. Trunk bifurcation reduced plant height
thus extending the time period of papaya production cycle under covered environments.
However, there was negative influence in number and average weight of harvested fruits. In
the greenhouses (plastic and plastic plus sombrite coverings) there were increases with respect
to: plant height, number of leaves, foliar area and time- life of leaves in the plant. In addition,
there were reductions in the incidence of black spot (leaves and fruits) and of fruit skin
freckles. In the shaded environments, percents of pentandric and carpeloid fruits were lower,
opposite to that of estaminate flowers. In the screnhouse (only sombrite net), a decreased
proportion of fruits reaching commercial standart occurred. In the greenhouse (plastic
covering), other benefitial effects were noticed, such as: anticipation of flowering and fruit
harvesting, due to the acceleration of fruit ripening in the plant. Although an increase in the
number pentandric, carpeloid and deformed, fruits was observed cultivation in the greenhouse
also induced a highly significant increment in yield of marketable fruits (around 67%)
compared with the natural environment. The results obtained indicated potential for organic
papaya cultivation under greenhouse conditions, as judging by the expressive gain in
productivity and plant health, besides the acceleration of the cycle. / O estudo foi conduzido no Sistema Integrado de Produ??o Agroecol?gica - S.I.P.A.
(Fazendinha Agroecol?gica Km 47), situado em Serop?dica,RJ, tendo como objetivos
acompanhar o desenvolvimento do ciclo e avaliar o desempenho agron?mico do mamoeiro
sob manejo org?nico, comparando duas formas de condu??o da planta (com e sem bifurca??o
do tronco), em ambiente natural e em tr?s tipos de ambiente protegido. Para tanto, mudas de
mamoeiro da cultivar Baixinho de Santa Am?lia, grupo Solo , foram transplantadas para tr?s
estruturas cont?guas: (a) estufa (cobertura de pl?stico), (b) estufa sombreada (cobertura
adicional de sombrite 30% sobre o pl?stico) e (c) telado (cobertura de sombrite 30%);
estabelecendo-se, ao lado, uma ?rea de cultivo em ambiente natural. Nas estufas (a e b), as
laterais e frentes foram revestidas com tela anti-af?dica. Nesses quatro tratamentos, 50% das
plantas hermafroditas tiveram o tronco bifurcado por meio de incis?o da gema apical, logo
ap?s a determina??o do sexo. Registraram-se, ao longo de 12 meses de cultivo: temperatura,
umidade relativa do ar e luminosidade em cada ambiente. Quanto ao desenvolvimento do
mamoeiro: altura da planta, di?metro do tronco, n?veis de enfolhamento, ?rea foliar e per?odos
de tempo para cumprimento de fases do ciclo, foram monitorados. Realizou-se, ainda, estudo
da biologia floral e das caracter?sticas dos frutos produzidos. Os tratos culturais empregados
obedeceram ?s normas t?cnicas da produ??o org?nica. Para compara??o entre ambientes de
cultivo, adotou-se o m?todo da an?lise conjunta de experimentos . A bifurca??o do tronco
reduziu a altura da planta prolongando o cultivo do mamoeiro nos ambientes cobertos. No
entanto, teve influ?ncia negativa no n?mero e no peso m?dio dos frutos. Nas estufas
(coberturas de pl?stico e de pl?stico mais sombrite) houve aumentos em rela??o a: altura da
planta, n?vel de enfolhamento, ?rea foliar e sobrevida das folhas. Por outro lado, ocorreram
redu??es da incid?ncia da var?ola (folhas e frutos) e da mancha fisiol?gica nos frutos. Nos
ambientes sombreados, os percentuais de frutos pent?ndricos e carpel?ides foram mais baixos,
ao contr?rio de flores estaminadas. No telado, registrou-se menor propor??o de frutos
atingindo padr?o comercial. Na estufa, ocorreram benef?cios do ponto de vista agron?mico,
destacando-se: antecipa??o do florescimento e do in?cio da colheita, al?m da acelera??o do
amadurecimento dos frutos na planta. Embora tenha havido aumento do n?mero de frutos
pent?ndricos, carpel?ides e aplastados, o cultivo na estufa proporcionou aumento altamente
significativo da produ??o de frutos comercializ?veis (em torno de 67%) em compara??o ao
ambiente natural. Os resultados obtidos indicaram potencial para o cultivo org?nico do
mamoeiro sob condi??es de estufa, em fun??o dos ganhos expressivos de produtividade e
sanidade, al?m de precocidade e acelera??o da colheita.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:tede/548 |
| Date | 19 January 2007 |
| Creators | Martelleto, Luiz Aur?lio Peres |
| Contributors | Ribeiro, Raul de Lucena Duarte |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Fitotecnia, UFRRJ, Brasil, Produ??o Vegetal |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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