Penggunaan Bap (Benzyl Amino Purin) Dalam Meningkatkan Bunga Betina Jarak Pagar (Jatropha Curcas L.)

Abstract

Jatropha curcas seed is a potential candidate as source of biodiesel. Seed yield, the determining factor of jatropha oil production, is highly associated with female flowers development.. However, little is known regarding floral development in this species. This study was undertaken to determine the effects of plant growth regulator Benzyl Amino Purin (BAP) on floral development of Jatropha curcas. The experiment was carried out in March through December 2011 at Cikabayan Experimental station, using Dompu accession.The treatment consisted of six concentration of BAP, i.e. 0. 40, 80, 120, 160, and 200 ppm. The experiment was arranged in randomized complete block design with three replicates, and each replicate consisted of three trees. The result show that application of BAP 160 ppm significantly increased the total number of female flowers per inflorescence up to over 7fold (from 3.30 - 23.67 flowers ) in the green house, where as outside the rumah kaca it reached over 5 fold (from 3.30 to 16 flowers).The number of male flowers was not affected by the treatment. As a result, the sex ratio between female and male flowers decreased from 1:15 to 1:3. Unfortunately, the increasing number of female flowers in the rumah kaca was followed by the low fruit set of 40% as opposed to those outside rumah kaca of 80%. It was possible that the low fruit set was due to lack of pollinators. There was indication that the developmental stage of flower bud determined the increase number of female flowers following the BAP treatment. The developmental stage 1 and 2 were the best time for application of BAP.