Relação fonte:dreno em melão Cantaloupe cultivado em ambiente protegido

• Autor(a) principal: Queiroga, Roberto Cleiton Fernandes de
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1265
• topic: Cucumis melo; Partição de assimilados; Rendimento; Poda; Qualidade; Cucumis melo; Productivity; Quality; Pruning; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

Two experiments were conducted at Universidade Federal de Viçosa- UFV with the objective of evaluating the effect of source:sink relation on physiological indices, productivity and quality of Cantaloupe melon fruits cultivated in a protected environment. Experiment 1 was conducted over the period from 9/25/2005 to 1/24/2006, in vases (11.5 dm3) filled with Gold Mix type 98 coconut fiber based substrate. The hybrids used were Torreon and Coronado , in a 2 x 2 factorial, randomized block experimental design, with five repetitions. Treatments consisted of number of fruits per plant (one and two) and fruit fixation position to the plant (from the 5th to the 8th knot and from 15th to the 18th knot). Experiment 2 was conducted over the period from 12/15/2005 to 3/19/2006 in soil cultivation, using the Coronado hybrid in split-plot, randomized block experimental design, with four repetitions. The number of fruits per plant (one and two) as allocated in the parcel, and, in the subparcels, the number of leaves per plant (16, 19, 22 e 25) was allocated. The characteristics of plant and fruit were evaluated in these experiments. In experiment 1 a greater dry mass in fruits was observed when they were fixed between the 5th and the 8th knot, which reduced leaf and stem dry mass in both hybrids. In the treatment where the fruits were fixed in the position from the 15th to the 18th knot, greater leaf area and leaf area rate and lower harvest index were observed in both cultivars. Plants with two fruits raised the specific leaf area, the leaf area index (in fruits between the 5th and the 8th knot in Torreon , only) and the haverst index in fruits coming from the 5th and 8th knot, in both hybrids. The highest fruit weight was obtained in plants with only one fruit and in fruits from the 15th and 18th knot. The highest commercial productivity was obtained in plants with two fruits in Torreon (22.71 and 28.27 Mg ha-1 in fruits from the 5th to the 8th knot and from the 15th to the 18th knot) and in Coronado (31.65 and 26.66 Mg ha-1 in plants with two fruits and between the 15th and the 18th knot). In these materials, when compared to plants with two fruits, the plants with only one fruit presented higher rind reticulation, pulp thickness, cavity diameter, length, diameter, fruit shape index (only in Torreon ), total soluble solids, maturation index, pH (only in Torreon ), total soluble sugars and non reducer sugars. In both hybrids, it was observed that plants with fruits fixed in position from the 15th to the 18th knot when compared to those with fruits fixed in position from the 5th to 8th knot, presented fruits with lower rind reticulation, cavity diameter, length, fruit diameter (plants with two fruits), total titratable acidity and higher pulp thickness (plants with one fruit), maturation index, pH, total soluble sugars and non reducer sugars (only in Coronado ), without alterations in fruit shape index and in total soluble solids. The handling of plants with only one fruit in experiment 2 provided a higher leaf dry mass (pruning at 25 leaves), stem dry mass, plant leaf area and leaf area rate (pruning at 22 and 25 leaves), leaf area index (pruning at 25 leaves), average fruit weight, rind reticulation, pulp thickness, length, diameter, cavity diameter, total soluble solids, total soluble sugars and non reducer sugars and lower fruits dry mass, total dry mass and plant leaf area (pruning at 16 leaves), specific leaf area, commercial productivity of fruits (45.38 Mg ha-1), when compared to plants with two fruits (53.16 Mg ha-1) pruning at 25 leaves. The other characteristics were not influenced by the number of fruits on the plant. The increase of the number of leaves per plant provided a quadratic response to culture cycle, leaf area rate (plants with two fruits), specific leaf area, cavity diameter and pH, with maximum points in 93.7 days, 33.7 cm2g-1, 171.0cm2g-1, 5.4 cm and 6.42, at plant pruned with 22.2, 23.0, 22.0, 20.8 and 23.0 leaves per plant, respectively. Increasing linear responses with increased number of leaves per plant from 16 to 25 were observed in the other evaluated characteristics, except for harvest index and total titratable acidity, which decreased.