<p>Soybean in Indonesia mostly is planted on the lowland during dry season. During the season, soybean crops face drought stress at generative phase, that reduces grain yield. Planting of drought tolerance variety is an alternative means to overcome this problem. The objective of this research was to evaluate the adaptability and yield stability of soybean lines tolerant to drought stress. Twelve soybean lines and two check varieties (Wilis and Tidar) were evaluated at eight locations during dry season of 2009 and 2010, planted two times in each location. The treatments were laid out in a randomized complete block design with four replications. These sites were Mojokerto, Banyuwangi, Pasuruan, and Jombang (East Java), Bantul and Sleman (Yogyakarta), Mataram and Lombok Barat (NTB). No irrigation was added during reproductive phase of the crop. Soil moisture content at 0-20 cm soil layer during the generative phase was equivalent to pF value of 3.0-4.2. Analysis of variance over locations and planting seasons showed that there was significant interaction between genotypes and environments. Among the tested-lines, DV/2984-330 was the only line that showed average stability with high grain yield, averaging of 1.95 t/ha out of its yield potential of 2.83 t/ha. This line showed good adaptability over locations with water shortage (20-30% field capacity) during generative phase. Grain yield of this promising line was 14% higher compared to that of Tidar and 16% higher to that of Wilis. This line is prospective to be released as new variety, possessing drought stress during generative phase.</p>

Porang (Amorphophallus muelleri Blume) is a tuber crop native to the tropics that belongs to the Araceae family. Porang is a potential tuber crops that has been known in Indonesia for a long time, but the value of its product has not been widely disclosed. The planting area covers over 45,000 ha with East Java as the main production areaMadiun-East Java has a long and the oldest history of porang cultivation in Indonesia and has great potential for porang development. Characterized and officially released its local cultivar as an official released cultivar would protect the local germplasm and can be used as a basis for character improvement. Porang Madiun 1 cultivar has morphological characteristics of compound leaf type, dark green-green leaf color. The color of the leaf edges is pink, but as the age of the plant increases, the leaf edges turn white. Porang leaf surface smooth-wavy, hairless. The edges of porang leaves are smooth- wavy, depend on sunlight intensity. Stem shape was round, stem color was green with white spots and longitudinal lines, The pattern of spots on the stems has a sparse density, with the color of the stems varying depending on the age of the plant. Shape of bulbil was irregular round with various size. Average corm weight of Madiun 1 was 0.1 kg for first year porang plant, 0.4 kg for second year porang plant, and 1.6 kg for third year it became 1.6 kg with the average number of bulbils 1.8, 4.9, and 16.7, respectively

ABSTRACT<br /><br />Twelve soybean shade tolerant promising lines and two check varieties, Pangrango and Argomulyo, were evaluated in eight locations covered varying degree of shades. The objective of this study was to assess the effect of genotype x environment interaction on seed yield and yield components, as well as on adaptation and yield stability of the lines  under those environments. The trial, in each location, was arranged in randomized block design repeated four times. The traits evaluated were days of flowering, maturity days, plant height, pod number, 100 seed weight, and seed yield. Light intensity was measured during generative phase, started at plants’ 30 days old,  two week interval. The results showed that genotype x environment interaction significantly affected those evaluated traits. Stability analysis revealed that four lines, i.e., IBK5-173-5-372, IBM22-861-2-22, IBM22-862-4-1, and IBM22-867-4-7 poorly adapted to the environments as indicated by coefficient regressions approximating 1.0 and low yield average. Eight lines, i.e., IBK5-143-3-7, IBK5-147-2-11, IBK5-172-4-36, IBK5-173-5-371, IIj9-299-1-4, IBM22-873-1-13, IBIj11-431-2-20, and AI26-1114-8-28, and the two check varieties, Pangrango and Argomulyo, were unstable. Of the 13 unstable genotypes, two lines, AI26-1114-8-28  and IBM22-873-1-13, gave higher average yield under shade condition (35%-70% shading level), 1.68 t/ha and 1.36 ton ha-1, respectively, than the two check varieties.<br /><br />Keywords: adaptation, Glycine max<br /><br />

<p class="teks">Tumpangsari (TS) kedelai dengan padi gogo atau jagung merupakan salah satu strategi meningkatkan luas panen dan produksi kedelai. Penelitian ini bertujuan untuk menentukan model tanam TS padi gogo (pg)+ kedelai (kd) dan TS jagung (jg)+ kedelai (kd) yang optimal. Penelitian dilaksanakan di IP2TP Kendalpayak mulai Oktober 2018 hingga Januari 2019. Perlakuan terdiri atas kombinasi empat model tanam  dengan dua varietas kedelai (Dega 1 dan Dena 1) termasuk pemupukannya pada TS pg+kd dan TS jg+kd. Varietas padi gogo dan jagung berturut-turut Inpago 10 dan Bima 19. Model tanam (M) pada TS pg+kd terdiri atas: M1: 75% pg + 91% kd tanpa pupuk, M2: 37% pg + 91% kd tanpa pupuk, M3: 37% pg + 152% kd dipupuk 23-36-30 kg/ha N, P, K + 1 t/ha pupuk kandang (pukan), dan M4: 18% pg+72% kd dipupuk 23-36-30 kg/ha N, P, K + 1 t/ha pukan. Padi gogo ditanam bersamaan dengan kedelai, dengan dosis pemupukan 144,5-52,5-52,5 kg/ha N, P, K + 1 t/ha pukan. Model tanam pada TS jg+kd terdiri atas: M1: 150% jg ditanam 3 minggu setelah kedelai + 114% kd dipupuk 38-15-15 kg/ha N, P, K, M2: 150% jg + 114% kd dipupuk 107-15-15 kg/ha N, P, K + 2,5 t/ha pukan, M3: 150% jg + 227% kd dipupuk seperti pada M2, dan M4: 52% jg + 70% kd dipupuk 23-36-36 kg/ha N, P, K + 1 t/ha pukan. Dosis pemupukan jagung 167,5-52,5-52,5 kg/ha N, P, K + 1 t/ha pukan. Hasil penelitian menunjukkan bahwa model tanam optimal pada TS padi gogo + kedelai adalah Model 1 dan Model 2 menggunakan kedelai varietas Dega 1, dengan keuntungan masing-masing Rp9.086.500 dan Rp8.896.500/ha. Model yang optimal pada TS jagung + kedelai adalah Model 1 menggunakan kedelai varietas Dega 1 dengan keuntungan Rp20.121.400/ha. Masing-masing model tanam tersebut mempunyai keunggulan dalam hal produktivitas dan perolehan keuntungan dibandingkan model lainnya yang diuji. Oleh karena itu, pada TS padi gogo + kedelai dengan Model 1 atau Model 2 atau pada TS jagung + kedelai dengan Model 1 lebih dianjurkan menggunakan kedelai varietas Dega 1 dibandingkan Dena 1.<br /><br /></p>

Background: Knowledge about genetic parameters can help plant breeders to determine which selection criteria are beneficial. This study aims to estimate the genetic parameters of soybean seed characteristics.Methods: A total of 91 soybean lines from three different populations were evaluated during dry season in 2016. All genetic material used was grown following a randomized complete block design with two replicates. Soybean pods were harvested after 90% of the leaves had yellowed or fallen. The characteristics of the seeds observed included length, width, thickness and weight of 100 seeds.Result: The results showed that there were two seed shapes (round and ellipse) and two seed sizes (large and medium). There is a broad genetic variability of soybean seed characteristics. Heritability broad sense varies from 0.42 to 0.84, classified as moderate (length-width ratio) to high (length, width, thickness, length-thickness ratio, width-thickness ration and weight of 100 seeds). This therefore shows that there is an opportunity to improve the characters of soybean seeds. The length, width, thickness, ratio of the three characters and the weight of 100 seeds can be used as selection criteria in a soybean breeding program to obtain large-seeded soybeans with a round or elliptical shape.