Leaf gas exchange and biomass partitioning in Jatropha curcas L. young plants subjected to flooding and drought stresses

Indonesia memiliki banyak tanah masam, tetapi penggunaan masih sangat sedikit karena kandungan nutrisi tanah masam rendah. Sementara itu, jarak pagar merupakan tanaman yang dapat tumbuh di berbagai jenis tanah (termasuk lahan marjinal) dan penggunaannya sebagai bahan baku biodiesel. Oleh karena itu, perlunya penelitian mengenai pertumbuhan jarak pagar pada tanah masam sebagai upaya untuk mengembangkan jarak pagar dan penggunaannya di Indonesia.Untuk memulai upaya, penelitian tentang berbagai genotipe jarak pagar di tanah masam telah dilakukan. Tujuan dari penelitian ini yaitu mempelajari genotipe jarak pagar yang berpotensi untuk tanah masam. Penelitian ini dilakukan di UPTD Pengembangan Teknologi Lahan Kering Singabraja, Kecamatan Tenjo, Bogor, Jawa Barat, dari November 2010-Agustus 201. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan satu faktor yaitu genotipe. Hasil penelitian menunjukkan berbagai perbedaan pada pertumbuhan diantara genotipe-genotipe jarak pagar. Secara umum, ada lima genotipe jarak pagar yang terbaik di tanah masam (pH 5.0) yaitu Medan I-5-1, Dompu, IP-2P-3-4-1, Sulawesi, dan Bima M.

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The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽

10.21273/hortsci.33.3.540a ◽

1998 ◽

Vol 33 (3) ◽

pp. 540a-540

Author(s):

K.J. Prevete ◽

R.T. Fernandez

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Gas Exchange ◽

Drought Tolerance ◽

Transpiration Rate ◽

Leaf Gas Exchange ◽

Gas Analysis ◽

Herbaceous Perennials ◽

Effects Of Drought ◽

Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

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