Rubber tree mini clonal garden: electric conductivity of the nutritional solution in the production of propagules

Abstract

The rubber tree (Hevea brasiliensis) is an important forest species that yields natural rubber. Traditionally, rubber tree grafts are cultivated in clonal gardens on soil, which necessitates enormous acreage. However, this approach is not only inefficient in terms of productivity, but it also has nutritional and water control constraints. A tiny clonal garden with a balanced fertilizer treatment is an approach that has previously been employed for other species. To apply this same system to the rubber tree, the goal was to investigate the effects of applying macro and micronutrients via fertigation on the productivity of a mini rubber tree clonal garden, as well as to assess the efficacy of using green stems produced under these conditions in three grafting techniques. Five dosages of macro and micronutrients were administered to grafted rubber tree seedlings (clone ‘RRIM 600’ on ‘GT1’) before transplanting them into plastic pots. A totally randomized design was adopted, with five treatments and ten replications, each with two plants per pot, for a total of twenty plants per treatment. The shoot apex was cut after 105 days, and the green stems measuring more than 20 cm were harvested throughout the course of a year. The number of stems was highest in the months of January to March 2014, after 135 days, reaching 3 green stems per plant-1 per month-1, and productivity increased up to an estimated electrical conductivity of 1.64 mS cm-1. Nutrition was found to boost the output of the rubber tree clonal mini garden as well as the survival of grafts after grafting. The tiny clonal garden is a potential method for getting more vegetative rubber tree propagules.