Aplikasi zat pengatur tumbuh untuk menyerempakkan mekar bunga dan masak buah jarak pagar (Jatropha curcas L.)

Abstract

One of the major constraints in Jatropha oil production is asynchronous fruit ripening, hence harvesting needs to be carried out accordingly which lead to drudgery. Therefore, an experimental study on the use of plant growth regulators was designed to induce synchronous blooming of pistilate flowers, and to promote synchronous fruits ripening. The study was conducted at the Jatropha Plantation of PT Indocement Tunggal Prakarsa Tbk Citeureup from October 2009 to August 2010. To induce synchronous blooming of pistilate flowers, Benzyl Amino Purine (BAP) and etephon were used, whereas etephon alone was used to promote synchronous fruits ripening. A completely randomized design was used in the first experiment that was carried in two steps. In the first step BAP at 0, 30, 35, 40, 45, 50 ppm and etephon at 10, 30, 50, 70 and 90 ppm were applied on early developing flower buds. In the second step 0, 30, 50, 70, 90 and 110 ppm BAP were used. The second experiment consisted of three steps. The first step was observation of seed development from 30 days after anthesis. A randomized complete block design was used in the second and the third steps. In the first step 0, 200, 400, 600, 800, 1000, and 1200 ppm of etephon were applied on fruits at 40 and 45 days after anthesis during the rainy season. In the second stage 0, 100, 200, 300, 400 ppm etephon were applied on fruits of the same maturation stages in the dry season. The result show that BAP tends to increase the number of female flowers in an inflorescence thus longer period of blooming. Application of etephon at 200 ppm on 40 day after anthesis shorten the fruit maturation hence more synchronous fruit ripening in rainy season, but not in dry season when fruits ripened synchronously. The quality of the seed and kernel were not affected by etephon application.