The Effect of Abiotic Factors and Elevation on The Diversity of Parasitic Nematodes in Garlic
Ayu Suci Wulandari (a*), Siwi Indarti (b)
a) Department of Pests and Plant Diseases, Faculty of Agriculture, Universitas Gadjah Mada Jln. Flora No.1 Bulaksumur, Sleman 55281, Yogyakarta, INDONESIA.
*ayuwulan797[at]gmail.com
b) Agrotechnology Innovation Centre (AIC), Universitas Gadjah Mada Jln. Tanjung Tirto, Kalitirto, Berbah, Sleman, Yogyakarta 55573, INDONESIA.
Abstract
Plant parasitic nematodes is one of the most prominent kind of pests in garlic which be able to cause large losses in agricultural production. The development of parasitic nematodes is influenced by various factors, including abiotic factors. The research was carried in sub-Laboratory Nematology, Department of Pest and Plant Diseases, Faculty of Agriculture, Universitas Gadjah Mada from January to June 2019. This study aims to determine three things: the types of parasitic nematodes in garlic at various elevations, the effect of abiotic factors on the abundance of parasitic nematodes in garlic, and the diversity and dominance of parasitic nematodes in garlic at various elevations in Central Java Province. Sampling was carried out in four cities: Brebes, Magelang, Tegal and Temanggung, in which all are locate in Central Java and the elevation are measured using the Geograpichal Positioning System (GPS). The isolation-Extraction of nematodes from soil samples was carried out using a modification of the whitehead tray method, while the isolation-extraction of nematodes from plant tissues (roots and tubers) was carried out by incubation method. Data were analyzed using a correlation test and regression to determine the relationship between pH, temperature, C-organic and C/N ratio with the population abundance of parasitic nematodes. The analysis was conducted using Ms. Excel. Diversity of parasitic nematodes garlic in various elevations were analyzed using the Index Shannon-Winner. The results showed that there were five parasitic nematodes genera in garlic, namely Ditylenchus sp., Helicotylenchus sp., Hoplolaimus sp., Rotylenchulus sp., and Pratylenchus sp.. The symptoms of garlic infected with parasitic nematodes include tubers experiencing discoloration to dark, nearly black; yellowing on the leaves; stunting of plants; and rolling leaves. Abiotic factors such as temperature has a positive influence on the abundance of Helicotylenchus sp., pH has a positive influence on the abundance of Pratylenchus sp., C-organic and C/N ratio has a positive effect on the abundance of Pratylenchus sp.. The diversity index of parasitic nematodes in garlic at various elevations is relatively low, ranging from 0,90-1,36. The dominance of parasitic nematodes in garlic at various elevations varies at the elevations >1600 masl, 1201-1400 masl and <1000 masl, the dominating parasitic nematodes are Ditylenchus sp., at elevations 1401-1600 masl, the predominant parasitic nematodes are Helicotylenchus sp., and at the elevation of 1000-1200 masl, the dominating parasitic nematodes are Pratylenchus sp..
Keywords: abiotic factors, elevation, garlic, parasitic nematodes
Topic: Environmentally Sustainable Agriculture