RESISTANT LEVEL OF SOYBEAN GERMPLASM AGAINST POD SUCKING BUGS (Riptortus spp.)

<p class="abstrakinggris">Increasing productivity of soybean has often been constrained by pod sucking bugs (<em>Riptortus</em> spp.) which caused a serious damage and yield losses up to 80%. Breeding for obtaining soybean variety resistant to pod suckers needs the availability of soybean germplasm resistant to the pest. The study aimed to obtain a candidate for soybean variety resistant to Riptortus spp. through the selection of 100 accessions of soybean. The study included the preparation of test plants and test insects, pest infestations, observations, and looking for a practical screening method for pod sucking pests. The experiment used a completely randomized design for two treatments (infested and non-infested <em>Riptortus</em> spp.). Cikuray variety and PI-092734 accession were used as a control. Results showed that there was a very low correlation among variables observed. Twelve soybean accessions showed a resistance to <em>Riptortus </em>spp., i.e. C7301-113AC-POP, Lokal Madiun-3549, Lokal Klungkung, ML.2974, Singgalang, Lokal Jepara, Lokal Jatim, Lokal Trenggalek, Lokal Tulungagung, Lokal Tabanan, Lokal Blitar, and Lokal Kuningan 10. These accessions were more resistant than the popular released variety such as Wilis, Grobogan, Detam 2, and Gepak Ijo. Small seed size was not a major determinant of soybean resistance to pod suckers. The addition of observational components, i.e. probing preference and oviposition, indicated that crop damage was indirectly influenced by the high frequency of probing and oviposition, although its relation to plant tolerant mechanisms still needs further investigation. Indeterminate plant types require further validation as to whether they contribute significantly to plant resistance against pod sucking insects.</p>

MANAGEMENT OPTIONS AGAINST POD BORER (MARUCA TESTULALIS GEYER) AND POD SUCKING BUGS (RIPTORTUS DENTIPES) OF COWPEA (VIGNA UNGUICULATA (L.) WALP.)

The efficacy of different management practices comprising cowpea/sorghum intercropping, microbial insecticide: Spinosad, neem-based botanical pesticide: neemix and synthetic insecticide: Chlorpyriphos 50 + Cypermethrin 5 were evaluated against pod borer and pod sucking bugs of cowpea. The experiment was laid out in completely randomized block design at Agriculture and Forestry University, Rampur, Nepal. All the treatments except cowpea/sorghum intercropping significantly reduced the flower infestation of pod borer larvae. The lowest number of infected flower and number of larvae per flower was observed in Spinosad treated plot. Also, the highest percentage of reduction in flower infestation was observed in Spinosad treated plots. Similarly, Chlorpyriphos 50 + Cypermethrin 5 treated plots showed the least number of pod bug infestation followed by Spinosad. The highest yield and lowest weight of damaged pod was recorded in Spinosad treated plots along with the lowest percentage infestation of pods by weight. The highest net income per hectare of land was recorded in Spinosad followed by Chlorpyriphos 50 + Cypermethrin 5 treatment. The marginal benefit cost ratio showed that the highest profit per unit rupee spent over control was obtained in Chlorpyriphos 50 + Cypermethrin 5 treatment followed by Spinosad. Considering the results obtained, Spinosad an eco-friendly, safe and less hazardous bio-pesticide has been recommended as a good approach for the management of cowpea pod borer and pod sucking bug.

RESPON GENOTIPE KEDELAI BIJI BESAR DAN UMUR GENJAH TERHADAP KOMPLEKS HAMA PENGISAP POLONG

Response of large seed size and early maturing soybean genotypes against pod sucking bugs complex. Pod sucking bugs (Hemiptera: Pentatomidae) is the most detrimental pest on soybean in Indonesia. These pest attacks caused the decreasing of quality and quantity of yield as well as decreased seed germination. The use of resistant varieties is an alternative control which is environmentally friendly. The objective of this study was to determine the response of various soybean genotypes against pod sucking complex in the field. The experiment was conducted on June to September 2015 in Pasuruan, East Java. The treatment was arranged in randomized block design, 16 treatments with three replicates. The treatment consists of 14 soybean promising lines (G 511 H/Anj//Anj///Anj-11-2, G 511 H/Anjasmoro-1-6, G 511 H/Anj//Anj///Anj-7-1, G 511 H/Anjasmoro//Anjasmoro-5-1, G 511 H/Argom//Argom-2-1, G 511 H/Anjasmoro-1-4, G 511 H/Anjasmoro-1-2, G 511 H/Anjasmoro//Anjasmoro-2-8, G 511 H/Arg//Arg///Arg///Arg-12-15, G 511 H/Anj// Anj///Anj-6-3, G 511 H/Arg//Arg///Arg///Arg-19-7, G 511 H/Anjasmoro-1-7, G 511 H/Anj//Anj///Anj////Anjs-6-7, G 511 H/Anjasmoro-1-4-2), and two varieties (Anjasmoro and Grobogan). The results showed that the differences in soybean genotypes significantly influence the intensity of damaged pod and seed caused by pod sucking bugs. The intensity of damaged pod was 29.8–64.0% per plant. The intensity of damaged seed was 13.2-63.9% per plant. The number of puncture was 1.2-1.6 punctures per pod and 0.6-2.7 punctures per seed. Based on the intensity of damaged pod and seed, genotipe G 511 H/Anjasmoro//Anjasmoro-2-8, G 511 H/Anjasmoro-1-2, and G 511 H/Anjasmoro-1-6 were indicated consistently as moderately resistance against pod sucking complex. Those three genotypes could be use as a source of genes to improve the resistance of soybean against pod sucking bug.

Identifikasi Ketahanan Sumber Daya Genetik Kedelai terhadap Hama Pengisap Polong

<p>Pod sucking bugs are the main insects pest that affect both yield quality and quantity of soybean seriously. There are three kinds of insect pest ie: Riptortus linearis (F), Nezara viridula (L), and Piezodorus rubrofasciatus. The soybean plants were mainly attacked by insects during seed and pod development decreased yield up to 79%. To identify soybean germplasm resistant to pod sucking bugs for breeding base material, 100 accessions of soybean germplasm were tested in Bogor Experimental Station during the wet season 2003. Each accession was planted in 2 m x 3 m plot with 40 cm x 15 cm plant spacing. There was no pest control during flowering stage until pod maturing stage. Data collected were population of each pod suckers bugs, percentage of seed and pods damage. The accessions with 0-20% of seed damage (score 1) were selected as the resistant genotypes. The result showed that among three kinds pod suckers, population of Riptortus linearis was higher then others. It was found nearly in each plot with different insect incident (score 1-4). Based on seeds and pods damage symptom, there were identified 17 accessions resistant to pod suckers. The lowest seed and pod damage caused by the insect were found in TGM 131-1-1-1B and GM425 Si accessions. The selected accessions were suggested to be used as parent materials for future breeding program.</p><p> </p><p><strong>Abstrak</strong></p><p>Hama pengisap polong merupakan hama penting yang dapat mengakibatkan penurunan hasil kedelai secara signifikan. Ada tiga jenis hama pengisap polong yang sering ditemukan menyerang pertanaman kedelai, yaitu Riptortus linearis (F), Nezara viridula (L), dan Piezodorus rubrofasciatus. Hama tersebut menyerang pertanaman kedelai selama stadia pengisian biji hingga menjelang polong masak. Serangan hama pengisap polong dapat menurunkan hasil kedelai hingga 79%. Sumber daya genetik (plasma nufah) kedelai tahan hama pengisap polong sangat diperlukan sebagai bahan dasar pemuliaan. Sebanyak 100 aksesi plasma nutfah kedelai telah diuji ketahanannya di Kebun Percobaan Cikeumeuh, Bogor, pada MH 2003. Setiap aksesi ditanam pada petakan berukuran 2 m x 3 m dengan jarak 40 cm x 15 cm. Mulai dari stadia pembungaan hingga polong masak tidak dilakukan penyemprotan hama. Pengamatan dilakukan terhadap populasi ketiga jenis hama pengisap polong, skor ketahanan/persentase biji, dan polong terserang. Aksesi dengan persentase biji terserang (skor 1) digolongkan pada aksesi tahan. Hasil penelitian menunjukkan, dari ketiga jenis hama pengisap polong, R. linearis ditemukan paling banyak, hampir pada setiap petak pengujian dengan tingkat serangan yang berbeda. Berdasarkan skor gejala kerusakan pada biji dan polong telah diidentifikasi 17 aksesi plasma nutfah kedelai yang tergolong tahan terhadap hama pengisap polong. Persentase biji dan polong rusak terendah ditemukan pada aksesi TGM 131-1-1-1B dan GM425Si. Kedua aksesi tersebut dapat digunakan sebagai sumber tetua persilangan dalam program pemuliaan untuk ketahanan terhadap hama pengisap polong.</p>

Comparative assessment of feeding damage by pod-sucking bugs (Heteroptera: Coreoidea) associated with cowpea, Vigna unguiculata ssp. unguiculata in Nigeria

Feeding trials were conducted on three (young, mid-fill and mature) developmental stages of cowpea Vigna unguiculata ssp. unguiculata pods in the screenhouse using fourth instar nymphs and adults of Anoplocnemis curvipes (Fabricius), Riptortus dentipes (Fabricius), Mirperus jaculus (Thunberg), Clavigralla tomentosicollis Stål and C. shadabi Dolling. Anoplocnemis curvipes was observed to be the most damaging coreoid species causing a yield reduction of 26.4–51.7% followed by R. dentipes (24.4–29.4%), M. jaculus (21.9–26.9%), C. tomentosicollis (17.9–22.4%) and C. shadabi (15.9–20.4%). The fourth instar nymphs of each pod-sucking bug species caused a significantly higher cowpea yield reduction than their respective adults. Similarly, infestation on young pods compared to mid-fill and mature stages resulted in significantly higher yield reduction. The results suggest that infestation levels of two fourth instar nymphs of A. curvipes or three fourth instar nymphs of the other four pod-sucking bug species per young pod should be adequate for screening of cowpea varieties for resistance to the coreoid bugs.