Kajian Penunasan Berat Pelepah terhadap Kuantitas dan Kualitas Bunga Jantan Kelapa Sawit serta Ketertarikan Elaeidobius kamerunicus FAUST

<p>Praktek penunasan berat pelepah kelapa sawit bertujuan untuk menghasilkan bunga jantan sehingga kebutuhan polen dan kumbang <em>Elaeidobius kamerunicus </em>dapat terpenuhi sehingga penyerbukan alami dapat menjamin pembentukan <em>fruit set </em>tandan yang normal. Penunasan berat dilakukan mulai tanaman umur 2 tahun dengan perlakuan penunasan hingga menyisakan hanya satu lingkar pelepah muda (8 pelepah/tanaman) dan sisa 2 lingkar pelepah muda (16 pelepah/tanaman) setiap bulan. Sebagai kontrol digunakan tanaman dengan penunasan normal yakni menyisakan 48-56 pelepah/tanaman. Hasil pengamatan selama 48 bulan menunjukkan bahwa terjadi peningkatan jumlah bunga jantan pada kedua perlakuan penunasan berat, jumlah produksi bunga jantan pada penunasan berat dengan menyisakan 8 pelepah/tanaman. Namun ukuran bunga jantan yang terbentuk lebih kecil (menurun sebesar 30,15-51,11%) bila dibandingkan dengan kontrol sehingga jumlah polen yang dihasilkan juga lebih sedikit dengan penurunan sebanyak 28,59-38,28%. Bahkan viabilitas polen kelapa sawit pada perlakuan penunasan berat juga berkurang 12,58-15,51%. Penurunan kualitas bunga jantan ini diikuti dengan penurunan jumlah kunjungan kumbang <em>E. kamerunicus </em>sebesar 22,63-31,01% dan penurunan jumlah kemunculan kumbang baru dari tandan bunga jantan lewat mekar sebanyak 40,89-49,40%. Kualitas bunga jantan pada kedua perlakuan penunasan berat tidak berbeda. Aplikasi penunasan berat pelepah kelapa sawit berdampak pada peningkatan kuantitas bunga jantan tetapi memiliki kualitas yang menurun bahkan kurang menarik bagi <em>E. kamerunicus </em>untuk berkembang biak.</p>

Minimum Effective Dose of Chlorantraniliprole and Chromafenozide to Control Oil Palm Bunch Moth Tirathana mundella Walker

The bunch moth, Tirathaba mundella is one of the leading pests in oil palm estates established on peatland. Severely infested male inflorescences usually would fail reaching anthesis. Reduction in the number of inflorescences at anthesis stage would suggest less food source and breeding ground for oil palm pollinating weevils, Elaeidobius kamerunicus, thus, affecting the fruiting percentage of oil palm and its yield. Despite to be less detrimental to the environment, biopesticide usages in the field is losing favour due to its slower rate of kill compared with conventional chemical pesticides, shorter persistence in the environment and susceptibility to unfavourable environmental conditions. The use of high host specificity chemical pesticides, such as chlorantraniliprole and chromafenozide are gaining popularity in pest management regimes. In this study, the optimum dose for chlorantraniliprole and chromafenozide in controlling T. mundella was assessed to provide valuable information for sustainable oil palm pest management. Several dosages of pesticide were evaluated for their effectiveness against T. mundella in a 7-year-old oil palm estate for six months. Based on the results obtained, application of 30 g or 40 g active ingredient (a.i.) per ha chlorantraniliprole were recommended to provide the longest protection period. To make plan for an effective pest management that could reduce material and labour cost per ha as well as the risks in developing pesticide resistance among pest, 30 g a.i per ha of chlorantraniliprole is recommended to be rotated with 25 g a.i. per ha chromafenozide for a total of four rounds in a year.

Responses of Oil Palm Pollinator, Elaeidobius kamerunicus to Different Concentrations of Estragoles

ABSTRACTElaeidobius kamerunicus is the main insect pollinator for oil palm (Elaeis guineensis) worldwide. One of the main reason E. kamerunicus attracted to oil palm inflorescences is estragole, a volatile organic compound released by the oil palm inflorescences during anthesis stage. However, the amount of estragole released from the oil palm inflorescence is varied due to the influence of abiotic and biotic factors and is seen to have an impact on E. kamerunicus pollination activity on the oil palm. To evaluate the responses of E. kamerunicus, different types (wild and reared) and sex (male and female) of E. kamerunicus were exposed to different concentrations (1, 5, 10, 30, 50, 70, 100, 150 and 200 ppm) of commercial estragole using four-arm olfactometer. Results showed that E. kamerunicus significantly preferred 100 ppm of estragole compared to other concentration (F = 139.81; d.f. = 9; P < 0.05). A significant interaction was also recorded between estragole concentrations and sexes of E. kamerunicus (F = 3.91; d.f. = 9; P < 0.05) where male E. kamerunicus was found to be more responsive to 100 ppm of estragole compared female E. kamerunicus. The E. kamerunicus responses to estragole is in line with the increase of estragole concentration up to 100 ppm. However, the response of E. kamerunicus was significantly decreased after the concentration value. The result of this study can be a good platform for future references since the estragole compound plays a significant role in oil palm’s flower pollination by E. kamerunicus. The factor of type and sexes of E. kamerunicus did not affect the preferences which indicated that E. kamerunicus reared in the laboratory have the potential to be released into the oil palm plantation area to overcome the problem of pollination.

Assessment of Oil Palm Pollinating Weevil (Elaeidobius kamerunicus) Population Density in Biparental dura × pisifera Hybrids on Deep Peat-Soil in Perak State, Malaysia

This study was conducted to assess the Elaeidobius kamerunicus (EK) population density among the biparental dura × pisifera hybrids’ palms on deep peat-soil. Twenty-four hybrids derived from 10 genetic sources were used. Variance analysis showed that the EK population density varies between different oil palm hybrids, with a more noticeable variation of a low population mean in the male weevil across the hybrids. The highest weevil population mean/spikelet was attained on the third day of anthesis. The maximum monthly population of EK/spikelet (12.81 ± 0.23) and population density of EK (1846.49 ± 60.69) were recorded in January. Accordingly, 41.67% of the hybrids recorded an EK population density greater than the trial means of 973.68 weevils. Hybrid ECPHP550 had the highest mean of EK/spikelet (10.25 ± 0.11) and the highest population density of EK/palm (1241.39 ± 73.74). The parental mean population was 963.24 weevils and parent Deli-Banting × AVROS recorded the highest EK population density (1173.01). The overall results showed a notable disparity in the EK population among the biparental hybrids. Parental Deli-Banting × AVROS and hybrid ECPHP550 could be more useful to optimize the weevil population for pollination improvements in palm plantations. However, we suggest that volatile production should be included as a desirable trait in oil palm selective breeding.

Beyond four decades of Elaeidobius kamerunicus Faust (Coleoptera: Curculionidae) in the Malaysian oil palm industry: a review

Oil palm (Elaeis guineensis Jacq) is an economically important crop in South-east Asia, especially in Malaysia and Indonesia. In Malaysia, oil palm is the most profitable commodity in the agriculture sector. The future of oil palm lies in obtaining a higher yield that is aligned and directed towards achieving the Sustainable Development Goals (SDG) by 2030. Elaeidobius kamerunicus was introduced into Malaysia during the late 1980s to boost the production of oil palm fruit bunches. Almost 40 years since the introduction of E. kamerunicus, significant improvements have been witnessed in the increase of oil palm yield. Nevertheless, the current concern in the oil palm sector is regarding the decreasing of fruit set that may be affected by E. kamerunicus. The weevil population plays a crucial factor in the pollination of oil palm. Several factors had been reported to reduce the weevil population such as natural enemies, interaction with local insects, pesticides, climate and male inflorescence. These factors have been addressed in this article based on various studies conducted since the first investigation in Cameroon by Syed in 1977. The role of the pollinator in terms of its biology, behaviour and pollination mechanism is also described in this article, together with the population management of the weevils. This review article will provide a summary of the current state of Elaeidobius kamerunicus in Malaysia and other neighbouring oil palm-producing countries.