FIRST REPORT OF EFFICACY STUDY OF BIOEXTRACT TO CONTROL PESTALOTIOPSIS SP. AFFECTING PARA RUBBER LEAF DISEASE (HEVEA BRASILIENSIS MUELL. ARG) UNDER CLIMATE VARIABILITY

Academic and industrial research experiments designed to stop the outbreak of Para leaf diseases caused by Pestalotiopsis sp. have been conducted in recent years in several nations. This manuscript reports a December 2019 to March 2020, study held in Thailand. This research tested the bio-efficacy of a natural bio-extract (YRU 1) fertilizer to fight Pestalotiopsis sp. in Natural Rubber (NR) plant leafs. Researchers conducted two separate experiments, in vitro and in vivo, using a mixture of distilled water and percentages of four natural ingredients. Results indicate that the bio-extract at 0.50% concentration level significantly decreased the number of Pestalotiopsis sp. colonies, in both in vitro and on rubber plant leaf (in vivo). Additionally, the use of the same concentration reduced fungal growth during new leaf development. The results suggest that the bio-extract used in these experiments is effective in reducing and controlling the direct development and growth of Pestalotiopsis sp. on leaves. It was suggested that a fluctuate in the climatic factors caused a negative impact on the leaf disease of rubber in southern Thailand. Use of natural bio-extracts therefore, may be used as an alternative to the toxic chemicals that threaten humans, animals and the surrounding environment