In Sulawesi, Indonesia, cocoa smallholdings are seriously affected by the cocoa pod borer (Conopomorpha cramerella, CPB). CPB is detrimental to both cocoa production and bean quality, and is a major concern to cocoa smallholders, processors, exporters and the international market. An Australian Centre for International Agricultural Research (ACIAR)-funded project was initiated to develop a locally applicable, farmer-participatory methodology for selecting and testing promising cocoa genotypes on farms. In a trial established on a farm in SouthEast Sulawesi, local Indonesian and international cocoa selections were propagated clonally by side-grafting onto mature trees of mixed genotype and evaluated for 2 years for pod value, quality and resistance to pest/diseases. Local selections were based on the observations of farmers, extension officers or researchers and included a number of clones specifically selected for resistance (or susceptibility, as checks) to CPB. Our results on the CPB-infestation of 34 clones in the trial indicate the potential of employing on-farm selection and testing to improve cocoa farms. Severity of infestation was determined in ripe pods according to whether the proportion of beans damaged by CPB larvae was light (less than 10%), moderate (10-50%) or severe (over 50%). Total CPB incidence in ripe pods for most of the clones was high, exceeding 75%, and was correlated with severe and light incidence, both of which varied more. The data support a model that predicts severe infestation inflicting bean losses occurs above a critical threshold of total CPB incidence. The cumulative CPB incidence in infested pods was significantly lower in a local selection, Aryadi 2, which also had fewer larval entry holes and a low exit/entry ratio indicating a degree of resistance to CPB. The incidence of lightly infested pods was significantly lower in the susceptible controls. Pod hardness was moderately high in Aryadi 2. However, VSD3 (a local selection), Scavina12, KKM22 and BR25, had low levels of severe infestation and/or high incidences of light infestation, but had relatively soft pods. This suggests that factors in addition to pod hardness might be involved in resistance, a possibility also supported by the positive correlation of CPB incidence in ripe pods with that in immature pods and the larger seasonal fluctuations of CPB incidence observed in resistant clones, compared to susceptible clones. In a mixed genotype stand, the lower CPB incidence observed in some clones might be explained partly by pest non-preference.
Spodoptera frugiperda is an invasive pest that has spread in various countries including Indonesia. S. frugiperda has many hosts but a high interest in maize. This study for determining the ability of Calotropis gigantea extract, Cresscentia cujete extract and mixed extracts in inhibiting the ability of S. frugiperda eggs to hatch and inhibiting the eating activity of S. frugiperda. The research has been done at the Pesticides and Natural Materials Laboratory, Faculty of Agriculture, Hasanuddin University. Observations were carried out by examination various concentrations (2.5%, 5%, 7.5%, and 10%) extracts of C. gigantea and C. cujete, while mixed extract with a concentration of 7.5% on the ovicidal ability and feeding inhibition of S. frugiperda larvae. The results showed that treatment with a concentration of 10% C. gigantea extract had an ovicidal effect percentage of 74.58% while the antifeedant percentage was 64.40%. Treatment extract of C. cujete with a concentration of 10% had an ovicidal effect percentage of 90.99% while the antifeedant percentage was 70.05%. Treatment with mixed extract with a concentration of 7.5% had an ovicidal effect percentage of 91.7% while the antifeedant percentage was 85.26%. The conclusion is the existence synergy between C. gigantea and C. cujete extracts had showed that the ovicidal effect and antifeedant activity will be even higher to S. frugiperda.
Paraeucosmetus pallicornis (Dallas) is a new pest in Indonesia which decreases rice production and quality. This pest causes the grains to become flat, hollow, brownish, break easily when milled, and bitter. This research represents the first study on Calotropis gigantea extract as an oviposition deterrent and ovicide against P. pallicornis. The study was conducted under laboratory conditions using four extract concentrations i.e. 0.5, 1.0, 1.5 and 2.0%. The oviposition deterrent effect was determined by counting the number of eggs laid and hatched. Percent reproductive control (PRC) and ovicidal activity was calculated using Tennyson's formula. Results indicated that all concentrations of C. gigantea leaf extract reduced the number of eggs laid and hatched. The PRC also showed a gradual reduction of oviposition of the P. pallicornis and the ovicidal activity ranged between 86.5 and 100%. The extract concentration which showed the highest potential as an oviposition deterrent and ovicide against P. pallicornis was in the range of 1.0-2.0%. The overall results indicated that C. gigantea leaf extract has the potential to be used as an oviposition deterrent and ovicide against P. pallicornis.
ABSTRAKPenyakit hawar daun Phytophthora yang disebabkan oleh Phytophthora palmivora merupakan salah satu kendala di pembibitan kakao di Indonesia. Pengendalian penyakit ini umumnya menggunakan fungisida sintetik, namun dampak negatif dari penggunaan fungisida sintetik ini mulai dirasakan. Penelitian dilakukan dengan tujuan menguji kemampuan dua isolat Trichoderma asperellum (ARBT-1 dan ART-4) menekan perkembangan penyakit hawar daun tersebut. Kedua isolat diaplikasikan melalui perlakuan benih dengan konsentrasi spora 10 4 mL -1 , 10 5 mL -1 dan 10 6 mL -1 . Intensitas penyakit dengan perlakuan konsentrasi spora tersebut berturut-turut adalah 39.0%, 23.6%, dan 21.8% untuk isolat ARBT-1 dan 30.6%, 25.7%, dan 30.8% untuk isolat ART-4, sedangkan pada perlakuan kontrol mencapai 90.3% pada 21 hari setelah inokulasi dengan patogen. Pengamatan jaringan daun setelah perlakuan menunjukkan bahwa kedua isolat T. asperellum ditemukan di dalam jaringan, menandakan sifatnya sebagai cendawan endofit.Kata kunci: cendawan antagonis, pembibitan, perlakuan benih ABSTRACT Phytophthora leaf blight caused by Phytophthora palmivora is one constraint in cacao seedling in Indonesia. Generally, synthetic fungicides were applied to control this disease but its negative impact is becoming obvious recently. Research was conducted to evaluate the effectiveness of two Trichoderma asperellum isolates, ARBT-1 and ART-4, to suppress disease development. The two isolates were applied through seed treatment with spore concentrations of 10 4 mL -1 , 10 5 mL -1 , and 10 6 mL -1 . The results showed that disease incidence on seedling treated with different spore concentrations of ARBT-1 was 39.0%, 23.6%, and 21.8%, respectively and those with ART-4 was 30.6%, 25.7%, and 30.8%, respectively, whereas disease incidence reached 90.3% for control at 21 days after inoculation of the pathogen. Observations on cocoa leaf tissues showed that the two isolates were found in leaf tissue, indicating that T. asperellum is an endophyte.
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