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Whiteflies are a severe threat to soybean production in the tropics. This study aimed to evaluate the soybean resistance level of the whitefly Bemisia tabaci in controlled and uncontrolled environments that is associated with plant age, damage intensity, and trichome density. The research was conducted under two conditions: non-sprayed (NS) and sprayed (SP). This study used 50 soybean genotypes arranged in a randomized block design with three replicates. The whitefly population was derived from natural infestations. The results showed that the highest wild population of B. tabaci occurred at 40 days after planting (DAP), i.e., 126.08 adults/plant in the NS environment and 22.57 adults/plant in the SP environment. The peak damage intensity occurred at 50 DAP, 20.71% in the NS environment, and 17.15% in the SP environment. In the NS environment, there were six resistant genotypes (including the resistant control G100H), 25 moderate, and 19 susceptible genotypes. In the SP environment, 19 genotypes were resistant, 22 genotypes were moderate, and nine genotypes were susceptible, respectively. Six soybean genotypes showed consistent resistance to B. tabaci in NS and SP environments. The low density of leaf trichomes in soybean may influence the high resistance to B. tabaci. The resistant genotypes identified in this study could be utilized in breeding programs for B. tabaci resistance. [ABSTRACT FROM AUTHOR]

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Pod shattering is one of the major soybean constraints in the soybean production centers, particularly in the tropics. The screening for pod shattering resistance of 16 genotypes was carried out using detached and undetached pod methods on the three different pod positions on the stem. The field research was arranged in a randomized block design, during the dry season in Banyuwangi, Indonesia. The shattering evaluation was conducted in the laboratory using the ovendry method. The screening methods to investigate the pod shattering resistance of each genotype consisted of the detached pod (DP), undetached pod (UDP), and undetached whole-stem method (UWS). The result showed that the detached pod method (DP) resulted in a higher average podshattering percentage (15%) than the undetached pod methods (UDP and UWS, 13% and 11%, respectively). Nevertheless, the detached pod and undetached pod methods provide a consistent result for the evaluation of pod shattering resistance, showed by their correlation coefficients (DP and UDP, r = 0.98**; DP and UWS, r = 0.98**, UDP and UWS, r = 0.99**). The detached pod with the oven-dry method was suggested to be used for screening of pod shattering resistance. This method enables to screen genotypes in greater numbers, provides a homogeneous selection pressure and environmental condition. Pods at the upper part of the stem were more resistant to shattering than those pods in the middle part and lower part. The pod length, seed length, seed weight, pod wall weight to the pod weight ratio, and weight of 25 seeds appeared to be the significant indicators for pod shattering resistance. The shattering evaluation resulted in five soybean genotypes (Anj/G100H-28, Anj/G100H-44, Anj/Rjbs-304, Anj/Rjbs-30, and Detap 1) with consistent resistance to pod shattering based on the three methods. These genotypes can be used as donor parents in the breeding program for pod shattering resistance. [ABSTRACT FROM AUTHOR]

Seed yield in soybean is associated with other yield components. The objective of the study was to investigate the pattern of relationship between seed yield and yield components in soybean. Agronomic characters and seed yield of 147 soybean homozygous lines (HL) and 3 check cultivars (Dega 1, Detap 1, and Anjasmoro) were evaluated in Banyuwangi (East Java, Indonesia) from April to July 2018. The field experiment was conducted in a randomized complete block design with 2 replications. After threshing, the HLs were grouped into large seed size (> 14.00 g/100 seeds) and medium seed size (10 - 14 g/100 seeds). The causation and inter-relationship between yield components and seed yield were quantified using path analysis. Based on the seed size, a total of 150 HLs was grouped into 97 lines and 53 lines of large and medium seed size, respectively. The correlation analysis showed a similar pattern between groups of large and medium seed size. The seed yield in both groups was highly determined by the characters of the number of filled pods, number of nodes, number of branches, plant height, and wet biomass. The results of path analysis revealed that plant age, particularly the length of the generative phase, was an important factor affecting seed yield in large seed soybean lines. The length of the generative phase determining the soybean yield in this study can be suggested to be used as selection criteria to obtain high yielding and large seed size variety. [ABSTRACT FROM AUTHOR]

One of soybean problem in Indonesia is leaf damage caused by the Spodoptera litura. The aim of the study was to identify the resistance of soybean genotypes against army worm based on the preference index and morphophysiological characters. A total of 150 soybean genotypes were grown under field condition from February to May 2018 in Malang (East Java, Indonesia). The preference test was conducted in the laboratory using G100H as resistant reference plant to armyworm. The result showed that the preference index was ranged from 0.09-1.82. A total of 105 genotypes showed a low preference index (resistant), 39 genotypes showed a high preference index (susceptible), and a genotype has similar preference index with the reference plant (has equal resistance with G100H). Based on the preference index and morphophysiological characters, 150 soybean genotypes can be grouped into eight clusters. A genotype from cluster VIII (Anjasmoro/Rajabasa-41) has characteristics of low leaf water content, dense leaf trichomes, and the preference index of 0.14. Those characteristics could be the attributes of the soybean genotypes that is resistant to S. litura. The Anjasmoro/Rajabasa-41 was recommended to be cultivated in Indonesian, or may be used as a gene source in the breeding program for S. litura resistance. [ABSTRACT FROM AUTHOR]

In Indonesia, soybean is mostly cultivated in lowland following the yearly planting pattern of paddy - paddy - soybean under zero-tillage condition. The research aim was to evaluate the agronomic performance of several soybean genotypes in lowland paddy fields under zero-tillage condition. A total of 12 soybean genotypes, including the check varieties of Wilis and Anjasmoro, were evaluated in lowland after rice planting in three locations (Klaten, Pasuruan, and Tabanan). A randomized block design with four replications was used in each location. The soybean yield is a complex character which determined by interrelated agronomic characters. The averages seed yield in Klaten, Pasuruan, and Tabanan were 2.97 t/ha, 3.02 t/ha, and 2.68 t/ha, respectively. Two genotypes produced equal yield with Anjasmoro, i.e. AT12-1062 (3.01 t/ha) and AT12-1037 (3.0 t/ha). Anjasmoro variety had the highest 100 seed weight (15.40 g), and only AT12-1035 showed the equal seed weight. The average days to maturity of 12 genotypes was 83 days. In addition to Anjasmoro variety, soybean genotypes AT12-1062 and AT12-1037 (medium maturity and medium seed size) as the new findings form this study were potential to be developed at lowland paddy fields under zero-tillage condition. The availability of the soybean genotypes adaptive to lowland paddy field under zero tillage condition is important to optimize the soybean productivity as well as the income of farmers in Indonesia. [ABSTRACT FROM AUTHOR]

The study is aimed at evaluating the pod shattering resistance of F8 soybean lines based on the shattering incidence and shattering severity. The materials consist of fourteen F8 soybean lines and two check cultivars. The pod shattering incidence was examined by using the oven-dry method, meanwhile, the shattering severity was evaluated based on the severity of the pod opening. The pod shattering resistance based on the shattering incidence resulted in five resistant lines (7-10% shattering), seven moderate lines (13-23% shattering), one susceptible line (53% shattering), and one very susceptible line (100% shattering). The pod shattering resistance based on the shattering severity showed that the pod opening on the ventral side differed between the lines and between the shattering degree, and it tends to form sigmoid curves with a different peak position for each shattering degree. The shattering severity of the resistant, moderate, and susceptible lines reached a peak at 60 °C, 50 °C, and 40 °C, respectively. A longer pod length indicated by the length of the dorsal (r = 0.827**) and ventral (r = 0.880**) sides of the pod, a higher total pod weight (0.827**), and a larger seed size (0.794**) will increase the degree of susceptibility to pod shattering. Those characteristics were considered to be the ones that should be used as the selection criteria in the breeding programme for pod shattering resistance in soybeans. [ABSTRACT FROM AUTHOR]

In Indonesia, cowpea (Vigna unguiculata L. Walp) is widely cultivated in the dry climate area. Famers used the seeds from previous plants or traditional markets. The aims of the study were to determine the effect of seed position in the pods on seed viability and to study the seed and seedling characteristics regarding the genetic variation and seed position. The cowpea used in this study was from 18 Indonesian local varieties. Twenty-five matured pods were randomly detached from each variety. Each pod was divided into three parts, i.e. the lower third (base), the middle third, and the upper third (tip). The seeds of each part were germinated using sand media to evaluate their viability. Each local variety has different response to the percentage of seed viability in each seed position in the pod. The highest abnormal germination occurred in the seed from lower part of the pod, followed by seed in the middle of the pod and the tip of the pod. The variation of seed viability in pods was more determined by genetic differences in local varieties. The average seed viability from three parts of the pods was highest for seeds originated from local varieties of Lumajang and Sampang. Therefore, it is recommended that the seeds of both local varieties can be mixed to be used for optimum cowpea cultivation. [ABSTRACT FROM AUTHOR]

Yam bean is legume with tuberous root originated from the semiarid tropics of Central America, and has been widely spread in several regions in Indonesia. Research on characterization of tuber yam bean was conducted in Kendalpayak Research Station (Malang, Indonesia) from May to October 2016. A total of 73 local yam bean cultivars originated from eight provinces were characterized based on their tuber characteristics. The sensory evaluation was also conducted to evaluate the tuber sweetness, fiber intensity, and texture crunchiness. The average tuber weight was 455.2 g/plant, with the average tuber length and width were 10.78 cm and 8.17 cm, respectively. The ratio of tuber length and width was 1.42, indicates that yam bean tuber in Indonesia tend to be in spherical shape. The average tuber water content was 83.87% (wet basis), showed that the water content was quite high. Based on cluster analysis, 74 local cultivars of yam bean were grouped into five clusters. The tuber weight varied among cultivars and become the distinguishing factor between local cultivars. Local variety of yam beans in Indonesia tend to have sweet taste and crunchy texture. So far, the study on characterization of tuber diversity in Indonesian local cultivar of yam bean is still limited. Thus, these results provide important information to optimize the tuber yam utilization as industrial raw materials. [ABSTRACT FROM AUTHOR]

Pod sucking bug, Riptortus linearis, is the most damaging soybean pest in Indonesia. A total of 24 soybean genotypes was identified for their resistance to pod sucking bug. The objective of the study was to classifying the resistance of some soybean genotypes against pod sucking pests. The research was conducted during the second dry season (July - October) 2016 in Ngale Research Station, East Java, Indonesia. The experimental design was arranged in randomized block design with five times repetition and two types of environment (full crop protection and controlled until 50 days of planting/dap). The resistance to pod sucking bug was evaluated based on seed damage, pod damage, and seed weight. The grouping of resistance was by using Chiang & Talekar's method (1980). A very high natural population of pod sucking bug was recorded in the research area as seen from the average number of damaged pod in full protection environment (L1) and insecticide control until 50 dap (L2), i.e. 41.45% and 60.16%, respectively. Genotype of G511H/Anj//Anj-2-8 was consistently resistant to pod sucking bug in L1 as well as L2. This genotype also had early days to maturity (78 days) and large seed size (15.57 g/100 seed), thus potentially to be developed in tropical area of Indonesia. The availability of genotype with such characteristics is in accordance with farmers' preference and also important to minimize yield losses. [ABSTRACT FROM AUTHOR]

A yield loss caused by pod shattering is one of the obstacles to the improvement of soybean productivity in tropical areas. The aim of this study was to identify the resistance of soybean genotypes to pod shattering as affected by agronomical and morphological characters. The field study was conducted in Malang, Indonesia, using 150 soybean genotypes. Data were collected on agronomical traits, the percentage of pod shattering and pod morphological traits. Identification for shattering resistance was done as per oven dry method. Percentage of pod shattering was ranged from 0 % up to 100 % shattering with a mean of 58.11 %. Pod shattering was found to be negatively correlated with a number of pod per plant, the thickness of the pod and Y/Z (seed weight and pod weight ratio). The Identification obtained 66 very highly susceptible genotypes, 19 susceptible genotypes, 19 moderate genotypes, 38 resistant genotypes and 8 very resistant genotypes. Two of eight very resistant genotypes (G511H/Anj//Anj///Anj////Anj-6-11 and G511H/Anj//Anj///Anj//// Anj-5-4) have high yield, medium maturity day and large seed size. Those lines could be used as gene donor for soybean varietal improvement for shattering resistance and recommended to propose as new improved soybean varieties resistant to pod shattering in Indonesia. [ABSTRACT FROM AUTHOR]

Soybean pod damaged by pod sucking bug (Riptortus linearis) is one of the constraint within soybean yield improvement in Indonesia. The research aimed was to identify the resistance of soybean genotypes to pod sucking pest. The experiment was conducted in Iletri's screen house from March to June 2015. The experiment was arranged in Randomized Completely Block Design using 10 soybean genotypes with three replicates. The soybean resistance was evaluated using no-choice test. Data collected on number of pod/plant, number of seed/plant, seed weight per plant, number of attacked pod/plant, and number of attacked seed/plant. The result showed that the lowest percentage both of pod and seed damage was G511H/ Anjasmoro//Anjasmoro-2-8, that was 25.83 % and 19.12 %, respectively. Based on the value of the percentage of seed damage, there were five susceptible genotypes, three moderately resistant, and two resistant genotypes. Based on the value of the percentage of pod damage, showed four susceptible genotypes, five moderately resistant, and a resistant genotype. G511H/Anjasmoro//Anjasmoro-2-8 was the only resistant genotype, and it could be used as a genetic source in the improvement of soybean resistance to pod sucking bug. [ABSTRACT FROM AUTHOR]

These last few years, the name of soybeans soared as a source of biodiesel. Soy biodiesel is an alternative fuel produced from soybean oil. Soybean potential as an alternative renewable energy source because it is expected to have the highest energy content compared to other alternative fuels. Opportunities to develop biodiesel using soybean oil in Indonesia is quite large, considering the soybean is a commodity that is already known and widely cultivated almost in all over Indonesia. In addition, the use of soybean for biofuel feedstock is expected to motivate farmers to cultivate soybeans, so their use is not limited to non-energy raw materials. Soybean varieties that have a high oil content as well as high yield is a source of major biodiesel feedstock. From 73 soybean varieties that have been released in Indonesia, has an average oil content of 18%. Varieties with high oil content can be used as raw material for biodiesel. Research on the use of soy as an ingredient of energy crops (biodiesel) have been carried out. In fact, soybean oil is the vegetable oil feedstock for most of the biodiesel being produced in the United States today. With the potential for soybean crops in Indonesia, both in terms of availability of land and varieties, the use of soybean oil for biofuel development in Indonesia is the flagship prospective materials for bio fuel substitute than other plants in the future. [ABSTRACT FROM AUTHOR]