Behavior of the foliar vigor in seringueira in different phenological periods

Abstract

The leaf vigor of the rubber tree shows variation during the year, reflecting phenological phases that influence the production of latex, in addition to periods susceptible to diseases and pests. Thus, the objective was to evaluate the foliar vigor of clones GT 1 and RRIM 600 in April and; in August, September and October, in the municipality of Itiquira - MT, with climate classified as Aw. The vigores of clones GT 1 and RRIM 600 were evaluated in April and; in August, September and October, months preceding the annual defoliation and subsequent to natural refoliation, respectively. The foliar vigor was evaluated based on the Normalized Difference Vegetation Index (NDVI), Landsat 5 satellite images where its averages were evaluated by Tukey test at 5% probability, with a randomized block design and two treatments (clones). In the analysis the two clones presented NDVI in April with average leaf vigor, occurring difference in NDVI means, with greater in RRIM 600. Between August and October the vigor was high, with no difference between the mean NDVI of these clones. Clone GT 1 older than 19 years showed a change of foliar phenology in April. The RRIM 600 clone, after the age of 17 or 18 years, it showed the beginning of phenological change of leaves in April.