Effect of water stress on the growth of four cashew line seedlings

anglais. Water shortage during the seedling growth stage of cashew is one of the limiting factors. Water available, has importance rule on the growth of cashew (Anacardium occidentale L.) seedling, especially when cashew is cultivated in dry climate regions. Therefore, the evaluation of some promising lines to water stress was conducted. The main goal of this study was to find out the promising cashew lines which tolerant to water stress; especially at seedling stages. The experiment was conducted in the green house of the Research Institute for Food Crop Biotechnology and the laboratory of Research Institute for Spice and Medicinal Crops, Bogor from May to August 2001. Factorial experiment with two factors and three replications was arranged in a randomized completely block design (RCBD). The first factor consisted of four promising lines, F2-8, III 4/2, P293 and B 0-2. The second factor was six levels of water stress (50 percent, 55 percent, 60 percent, 65 percent, 70 percent and 75 percent) field capacity (FC). Data observation included the growth of seedling (height of seedling, number of leaves, leaf area/plant), dry weight (seedling) and content of free proline. The results of the experiment indicated that interaction between promising lines and water stress significantly affected the proline content. The highest proline content was found on number BO-2 at 50 percent FC, however, it was not significantly different from number F2-8, while the lowest proline content was found on number III4/2 at 75 percent FC. The free proline content was also increase as water available decrease. Single factor, promising lines and water stress were significantly affected to the growth of seedling F2-8 and III4/2 produced better on growth and dry weight of seedling up to 70 percent field capacity (FC). The growth of seedling was obviously normal and did not significantly different among promising lines, however, bellow 65 percent (FC) growth of seedling was significantly affected by water available. Based on the growth of seedling and proline content indicated that F2-8 were more tolerance to water stress compared to others lines.

indonésien. Ketersediaan air pada fase pembibitan, merupakan salah satu faktor pembatas dalam pertumbuhan bibit jambu mente. Tujuan penelitian adalah untuk mendapatkan nomor harapan jambu mente (Anacardium occidentale L.) yang toleran terhadap cekaman air, khususnya pada fase pembibitan. Percobaan dilaksanakan di rumah kaca Balai Penelitian Bioteknologi Tanaman Pangan dan Laboratorium Balai Penelitian Tanaman Rempah dan Obat, dari bulan Mei-Agustus 2001. Rancangan faktorial dengan dua faktor dan tiga ulangan disusun dalam rancangan acak kelompok. Faktor pertama adalah empat nomor harapan jambu mente yaitu: F2-8, III 4/2, P 293 dan B 02, dan sebagai faktor kedua adalah enam tingkat cekaman air yaitu: 50 persen, 55 persen, 60 persen, 70 persen dan 75 persen kapasitas lapang (KL). Parameter yang diamati meliputi: pertumbuhan bibit (tinggi, jumlah daun, luas daun), bobot kering bibit (batang, daun dan akar), serta analisis kandungan prolin bebas. Hasil percobaan menunjukkan bahwa interaksi nomor harapan dengan perlakuan cekaman air berbeda nyata terhadap kandungan prolin bebas. Kandungan prolin bebas tertinggi terdapat pada nomor B 0-2 pada cekaman air 50 persen KL, tetapi tidak berbeda nyata dengan F2-8, sedangkan kandungan prolin terendah didapatkan pada nomor III 4/2 dengan cekaman air 75 persen KL Faktor tunggal nomor harapan berbeda nyata terhadap pertumbuhan bibit dan bobot kering bibit jambu mente. Dari empat nomor harapan yang diuji didapatkan bahwa nomor F2-8 mempunyai pertumbuhan bibit (tinggi, jumlah daun) dan bobot kering bibit yang paling tinggi dibandingkan nomor lainnya, sedangkan nomor B 0-2 mempunyai pertumbuhan bibit (tinggi dan jumlah daun) dan bobot kering bibit yang paling rendah. Faktor tunggal tingkat cekaman air berbeda nyata terhadap pertumbuhan dan bobot kering bibit. Dari enam tingkat cekaman air didapatkan bahwa sampai cekaman air 70 persen KL pertumbuhan bibit (tinggi, jumlah daun, luas daun) tidak berbeda nyata, akan tetapi pada cekaman air 65 persen KL pertumbuhan dan bobot kering bibit berbeda nyata. Berdasarkan pertumbuhan bibit dan kandungan prolin bebas, dapat dikemukakan bahwa nomor F2-8. Lebih toleran terhadap cekaman air dibandingkan dengan nomor lainnya.