The effects of kencur (Kaempferia galanga L.) extract and storage period on seed borne fungi and citrus (Citrus sp.) seed viability

Abstract

Abstract. The recalcitrant seeds need a high moisture level during storage to prevent losing their viability. The storage at a high moisture level is a favorable condition for fungi growth, and on the other hand, a low seeds moisture level will lose the viability of the seeds. As one of the recalcitrant seeds, the citrus seeds need a special condition in storage. The storage of citrus seeds using kencur (Kaempferia galangal L.) extract can protect the seeds against fungi during storage and preserve their viability. This research aimed to determine the best concentration of K. galanga extract, which protects the citrus seeds against fungi as long as period storage, the kind of fungi and its percentage of infection, and the citrus seeds viability. This research was carried out from September until November 2004 at Plant Pest and Disease Laboratory and Greenhouse of Agricultural Faculty of Sebelas Maret University. The citrus seed used was Keprok variety from Ponorogo. The research design was a Randomized Completely Block Design (RCBD), with the treatments: (i) included the seeds without being stored and without being given by K. galanga extract, (ii) the seeds were stored for 2 weeks with 100%, 75%, and 50% K. galanga extract, (iii) the seeds were stored for 4 weeks with 100%, 75%, and 50% K. galanga extract, (iv) the seeds were stored for 6 weeks with 100%, 75%, and 50% K. galanga extract, and (v) the seeds were stored for 8 weeks with 100%, 75%, and 50% K. galanga extract. Data were analyzed using the F test with 5% and 1% significance levels. If there were fundamental differences, it continued to be tested using a Duncan multiple range test with a 5% significance level. This research showed that K. galanga extract by 50% was the best concentration that protected the citrus seeds against fungi for 2 weeks of storage. Storing citrus seeds with K. galanga extract for more than 2 weeks decreased seeds viability. The dominant fungi that attack citrus seeds in the storage were Aspergillus spp. and Penicillium spp., obtained using a blotter test.