Crescimento e produção de taro [Colocasia esculenta (L.) Schott] sob intensidades e períodos de sombreamento

• Autor(a) principal: Gondim, Ancélio Ricardo de Oliveira
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4461
• topic: Colocasia esculenta; Produtividade; Sombreamento; Crescimento; Colocasia esculenta; Yield; Shade; Growth; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

With the aim of obtaining information for the intercropping of taro with other species, an experiment with levels and periods of shade was carried out. The experiment was installed in the Horticultural Experimental Fields of the Federal University of Viçosa, from 04/10/2004 to 04/07/2005. The experiment consisted of 13 treatments, four shade levels (control = full sunlight; 18, 30 and 50% of shade kept during all the cycle), along with the implementation of the shade levels (18, 30 and 50%) in three periods of the crop cycle (initial = 0 - 3 months; intermediate = 3 - 6 months; and final = 6 - 9 months). The shade levels were obtained by the installation and maintenance of Sombrite® screens, approximately 0.50 m above the canopy. For plant growth evaluation, it was considered an arrangement having time as subplots, with eight plant collections carried out at the 60, 90, 120, 150, 180, 210, 240 and 270 days after planting, using the experimental design of randomized blocks, with four repetitions. The data were analyzed by ANOVA, and means of each treatment were compared with the control (100% of light) by the Dunett test (P<0.05). The plot consisted of six 3-m length rows spaced of 1,00 x 0.30 m, totalizing 60 plants, in an 18 m2 area. The evaluated growth parameters were: leaf area, specific leaf area, leaf mass ratio and leaf area ratio, leaf fresh and dry matter, petiole length and diameter, petiole fresh and dry matter, corm and cormel fresh and dry matter, total dry matter, dry matter partition, cormel number, plant height, leaf number/plant and cormel starch content. The production was evaluated at 270 DAP, for mass and number of corms (RM), large (FG), medium (FM) and small (FP) cormels, marketable cormels (RC = FG + FM + FP) and total cormels (PT = RM + RC). Taro plants grown under 50% shade during all the cycle showed greater investment in the production of shoot and corm biomass, to the detriment of cormels, as well as lower starch content in the cormels. Under 18% of shade during all the cycle or in any of the periods, there was good plant development, with increased leaf area and shoot and cormel biomass production. Shade during all the crop cycle, particularly under the highest levels, provided higher yields of RM and FP and lower yields of RC, FG and FM. Shade in the three periods resulted in reduction in the studied parameters, except for the productions of RM and FP and mean mass of RC, being 18% shade in the initial and intermediate periods which less reduced PT and PC, not differing from the control.