The Effect of Abiotic Factors and Elevation on the Diversity of Plant Parasitic Nematodes in Garlic on Central Java, Indonesia

Plant-parasitic nematodes are one of the most prominent type of pests in garlic (Allium sativum L.). To determine the influence of elevation and soil abiotic factor to abundance and diversity of plant parasitic nematode in garlic crops, this research was conducted Sampling was carried out in four locations: Brebes, Magelang, Tegal and Temanggung, Central Java, Indonesia. Samples of soil, roots and tubers were collected. Soil abiotic factors are taken measurements such as pH, temperature, and organic matter. The altitudes are measured using the Geograpichal Positioning System (GPS). The results showed that there were five parasitic nematodes genera in garlic, that are Ditylenchus sp., Helicotylenchus sp., Hoplolaimus sp., Rotylenchulus sp., and Pratylenchus sp. Abiotic factors as temperature has a positive influence on the abundance of Helicotylenchus sp., pH has a negative influence on the abundance of Hoplolaimus sp., organic matter 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 to 1.36. The dominance of plant parasitic nematodes in garlic at various elevations varies at the elevations >1 600 m a.s.l, 1 201 m to 1 400 m a.s.l and<1 000 m a.s.l. The dominating plant parasitic nematode was Ditylenchus sp., found at 1 401 m to 1 600 m a.s.l elevation, the predominant plant parasitic nematode was Helicotylenchus sp., found at 1 000 m to 1 200 m a.s.l elevation, and the dominating plant parasitic nematode was Pratylenchus sp. found at less 1 000 m a.s.l elevation.