Witjaksono Witjaksono
Department of Plant Protection, Faculty of Agriculture, Universitas Gadjah Mada Jln. Flora No. 1, Bulaksumur, Sleman, Yogyakarta 55281

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Analysis of Volatile Compound at Different Age of Corn Crops Used as Bemisia tabaci Repellent Retno Wikan Tyasningsiwi; Witjaksono Witjaksono; Siwi Indarti
Jurnal Perlindungan Tanaman Indonesia Vol 23, No 1 (2019)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jpti.35954

Abstract

Bemisia tabaci is one of the red chili pests that plays a role as a Begomovirus vector. This vector can be controlled through Integrated Pest Management (IPM) practices. One of the potential practices is by utilizing corn as a barrier crop to prevent the vector from attacking the main crop. The aim of this research was to examine the repellence activity of the volatile compound obtained from various ages of corn crop against B. tabaci. The volatile compound was collected from the corns at 4 week after planting (WAP), 6 WAP, 8 WAP, 10 WAP, and 12 WAP. Volatile compound capture device was designed with two solvents, i.e. hexane and ethanol, then the volatile compound analyzed by Gas Chromatography Mass Spectrometry (GC-MS). B. tabaci repellency against volatile compound was examined using Y-tube olfactometer. Each treatment was employed with 5 replications. Data were analyzed using ANOVA with 95% and further analyzed by Least Significant Different (LSD). The parameter observed was the total of B. tabaci avoided the volatile compound tested until half of the control olfactometer arm. The results showed that all ages of the corn produced repellent compound and the most optimal were corn aged 12 WAP with repellency rate of 83.72%. GC-MS analysis identified the volatile compound were citronella, limonene, β-phellandrene, β-caryophyllene, 1.8 cineole, farnesol, caryophyllene, and patchouli alcohol.
Farmers’ Practices in Using Insecticides to Control Spodoptera exigua Infesting Shallot Allium cepa var. aggregatum in the Shallot Production Centers of Java Gracia Melsiana Aldini; Y. Andi Trisyono; Arman Wijonarko; Witjaksono Witjaksono; Herman de Putter
Jurnal Perlindungan Tanaman Indonesia Vol 24, No 1 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jpti.47893

Abstract

The beet armyworm, Spodoptera exigua Hübn. (Lepidoptera: Noctuidae) is a major insect pest of shallot in Java. This research was aimed to determine how insecticides were used as the common farmers practice  for controlling S. exigua. The research was conducted in three shallot production centers in Java: the Districts of Brebes (Central Java Province), Nganjuk (East Java Province), and Bantul (the Special Region of Yogyakarta).  Surveys were conducted by interviewing thirty shallot farmers as respondents from each district. The selected thirty farmers were taken from  four sub-districts. Almost all farmers (93.3%) in the three districts had similar perception that S. exigua was the major insect pest in shallot and 84.4% farmers stated that this insect was difficult to control. The four most common insecticides active ingredients  used were chlorfenapyr, methomyl, chlorpyrifos, and emamectin benzoate. Insecticides remained the first choice and they were applied throughout the shallot season mostly based on the calendar (1-3 days interval). When using insecticides farmers tend to exceed the label recommended rates, and the farmers mostly mixed different insecticides into one spray solution. These results suggest that application of insecticides to control S. exigua was already exessive. The potential risks and efforts essential to minimize the risks are discussed. 
The Coexistence of Oryctes rhinoceros L. and Xylotrupes gideon L. (Coleoptera: Scarabaeidae) on Immature Plant in Oil Palm Plantation Anugerah Pustakawan Pradipta; F. X. Wagiman; Witjaksono Witjaksono
Jurnal Perlindungan Tanaman Indonesia Vol 24, No 1 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jpti.52582

Abstract

Oryctes rhinoceros L. and Xylotrupes gideon L. (Coleoptera: Scarabaeidae) are known to attack palms. O. rhinoceros is a major pest in oil palm while X. gideon is a minor pest found in certain areas with a relatively few numbers. Collecting these beetles by hand picking and trapping are intended to reduce their population. Objectives of this study were to describe an intimacy of shared existence of O. rhinoceros and X. gideon in the oil palm plantation, and to determine the effect of manual collection of the beetles from the decomposing trunks compared to those that were collected using attractant traps. The study was conducted in Asahan Regency, North Sumatera, in Sei Silau PTPN III oil palm plantation. Five traps (2 Ha/trap) containing the pheromone ethyl-4-methyloctanoate were installed randomly at a replanting area of immature palm. Beetle collection was performed daily for 30 consecutive days using two methods, i.e. (a) hand-picking of beetles on the decomposed trunks at surrounding the trap for 2 hour per day, and (b) using pheromone traps. Simple regression and correlation model was used for data analysis. Results showed that coexistence of O. rhinoceros and X. gideon was observed at the breeding sites of decomposing trunks, but not in the traps, and their coexistence showed a weak relationship (r = 0.12). Number of collected O. rhinoceros (221 beetles) was much more than X. gideon (82 beetles). Natural sex ratio (male: female) was approximately 0.5 for O. rhinoceros and 0.4 for X. gideon. Collection of the beetles in the decomposed trunks showed a moderately positive relationship (r = 0.43) with, and significantly influenced (18.73%) to the collection of beetles using pheromone traps.