Vol. 6, Issue 7, Part E (2020)

Abstract
Tapping panel dryness is an important limiting factor in rubber productivity of Hevea brasiliensis. In order to assess the sensitivity to this syndrome, the effect of two intensive latex harvesting technologies on clone GT1, moderate-metabolism one, was studied in the southeastern region of Côte d'Ivoire. The rubber trees were planted according to the single-tree experimental design, “single-tree plot design”, a tree constituting a repetition, and 31 trees per treatment, selected on the basis of girth and health status criteria. The parameters measured were rubber yield, girth increment, physiological condition and sensitivity to tapping panel dryness. The results obtained showed that the latex harvesting system (S/2 d/3 6d/7 AND 10 % Pa 1 (1) 1/w) significantly induced little tapping panel dryness (0.18 %) than that of the control (S d/1 6d/7 unstimulated, 1.43 %). Its rubber productivity was good (62 g.t^-1.t^-1) and it mainly induced less stress that could cause physiological fatigue or even tapping panel dryness. Moreover, rubber yield, radial vegetative growth, physiological parameters of the latex and tapping panel dryness rate were influenced by both treatments applied to GT 1. Furthermore, medium and high sucrose (16.5 %) and thiol group (0.51 mmol.l^-1) contents of the latex regarding the treatment (S/2 d/3 6d/7 AND 10% Pa 1 (1) 1/w), were decisive in the response to this stimulation. The sensitivity to tapping panel dryness was in very close linear relation with the latex harvesting intensity to which clone GT 1 was subjected.