Rambutan is a fruit native to Indonesia, which has a high diversity. Indonesian Tropical Fruit Research Institute has a rambutan germplasm collection. The objectives of the research were to identify and classify rambutan germplasm accessions based on morphological characteristics, in order to identify the specific characteristics important for the development of future varieties of rambutan. Collecting data on the 32 accession was conducted in Aripan Experimental Field, Indonesian Tropical Fruit Research Institute from September 2014 to February 2015. Characterization of morphology characters referred to as the Descriptor for Rambutan was published by IPGRI. Cluster analysis based on morphological characteristics successfully separated the accession of rambutan R7 and R11 with 30 other rambutan accessions with the dissimilarity coefficient of 45%. Accession R4 was similar to Sitangkue, R14 was similar to Korong Gadang, and R15 was similar to Sinyonya. Characteristics that can be used to distinguish each of the accession of rambutan were the width of seed, seed thickness, total soluble solids (TSS), fruit diameter, spintern texture and the spintern color. Accession R15 can be developed as a commercial variety, because it has a high yield, and shelf life associated with high fruit weight characteristics and thick rind.

<p>Plasma nutfah merupakan bahan dasar yang sangat penting untuk mendapatkan varietas unggul baru. Tujuan penelitian ini ialah mengarakter dan mengevaluasi koleksi plasma nutfah durian berdasarkan karakter morfologi buah. Penelitian dilakukan di KP. Aripan dan KP. Subang Balai Penelitian Tanaman Buah Tropika mulai bulan Januari 2011 sampai Desember 2012. Karakterisasi buah dilakukan terhadap 38 aksesi durian yang berumur 20 – 26 tahun. Sebanyak 5 – 10 buah dikarakter tiap  aksesi. Hasil penelitian menunjukkan bahwa aksesi yang diuji mempunyai karakter buah yang beragam dalam  ukuran , bentuk,  warna, maupun kualitasnya. Sunan mempunyai  karakter unggul terbanyak yaitu  daging buah tebal, panjang duri sedang, biji kecil, persentase biji kempes &gt; 25%, dan rasa sangat manis.  Hasil penelitian ini diharapkan dapat dimanfaatkan untuk pertimbangan dalam pemilihan  varietas unggul atau tetua durian yang tepat dalam program perakitan varietas unggul baru.</p>

<p>Kentang merupakan tanaman pangan bernilai ekonomi tinggi yang rentan terhadap serangan busuk daun (Phytophthora infestans) pada musim penghujan. Penggunaan pestisida sintetik hasilnya belum memuaskan sehingga perlu dilakukan induksi ketahanan terhadap serangan penyakit. Tujuan penelitian untuk mengetahui pengaruh  pemberian asam salisilat dan K2HPO4 dalam meningkatkan ketahanan tanaman kentang pada musim penghujan terhadap penyakit busuk daun. Penelitian dilakukan di Kebun Percobaan Berastagi pada ketinggian tempat 1.340 m dpl. pada bulan September sampai dengan Desember 2015. Tata letak percobaan disusun berdasarkan rancangan acak kelompok dua faktor dengan tiga ulangan dan 18 kombinasi perlakuan. Faktor pertama adalah dosis asam salisilat  (a0 = 0, a1 = 0,1g/L, a2 = 0,2 g/L, a3 = 0,3 g/L, a4 = 0,4 g/L, dan a5 = 0,2 g/L propineb). Faktor kedua adalah dosis K­2HPO4 (k0  =  kontrol, k1 = 0,1 g/L, k2 = 0,2 g/L). Hasil penelitian menunjukkan bahwa kombinasi perlakuan 0,1 g/L asam salisilat dan  0,1 g/L K2HPO4 merupakan perlakuan terbaik menurunkan intensitas penyakit P. infestans dan kerusakan umbi kentang. Intensitas penyakit sampai 9 minggu setelah aplikasi hanya 7,46%, sedangkan kerusakan umbi hanya sebesar 0,35%. Jumlah umbi dan persentase kelas umbi per tanaman hanya dipengaruhi oleh K2HPO4, sedangkan bobot umbi tidak dipengaruhi kedua perlakuan. </p><p><strong>Keywords</strong></p><p>Kentang; Asam salisilat; K­2HPO4; Ketahanan; Musim penghujan</p><p><strong>Abstract</strong></p><p>Potatoes are high economic value crops that are vulnerable to the attack of late blight (Phytophthora infestans) in the rainy season. The use of synthetic pesticides has not been satisfactory, so that should be induced for the disease resistance. The objective of the research was to determine the giving effect of salicylic acid and K2HPO4 in improving the resilience of the potato crop in the rainy season to late blight. The study was conducted at Berastagi Experimental Garden in altitude 1,340 meters above sea level, from September to December 2015. The layout of the trial is based on two factor randomized complete block design with three replications and 18 combination treatments. The first factor is the dose of salicylic acid (A0 = 0, A1 = 0,1g/L, A2 = 0,2 g/L, A3 = 0,3 g/L, A4 = 0,4 g/L and A5 = 0,2 g/L propineb), the second factor is the dose K 2HPO4 (K0 = control, K1 = 0.1 g/L, K2 = 0.2 g / L). The results showed that the combination treatment of 0.1 g/L of salicylic acid and 0,1 g/L K2HPO4 is the best treatment because it can reduce the intensity of the Phytophthora infestans disease and potato tuber damage. The disease intensity up to 9 weeks after application only 7.46%, while the tuber damage only 0.35%. The number and percentage of class tubers per plant only affected by K2HPO4, while the tuber weight was not influenced both treatments.</p>