Perlakuan Iradiasi Sinar Gamma [60Co] untuk Pengendalian Kutudaun Macrosiphoniella sanborni (Gillette) pada Bunga Potong Krisan (Chrysanthemum morifolium var. Jimba Lima)

Abstract

Chrysanthemum cut flowers has high economic values and popular flower because it has many varieties with shape, size, color, and longer vase live of flower compared to other cut flowers. However, an infestation of Macrosiphoniella sanborni on chrysanthemum cut flowers can reduce the aesthetics of flowers, cause economic loss, and restrict export trading. Gamma irradiation [60Co] will be an alternative quarantine treatment against M. sanborni on chrysanthemum cut flowers. The advantages of gamma irradiation treatment including highly penetrating ability are considered to be effective for quarantine treatments, practical treatment, and the absence of any residue that could endanger consumers. This study was carried out to study M. sanborni’s life cycle with different temperatures and humidities, determine the effective dose of gamma irradiation [60Co] against M. sanborni, and evaluating of the effect on Chrysanthemum morifolium cv. Jimba Lima. The five steps of this research process were identification of M. sanborni, mass rearing and life cycle observation of M. sanborni, preliminary test on M. sanborni (nymphs and adult), sublethal dose test on M. sanborni (adult), and evaluation of their effects on quality of flowers. A preliminary test was performed by using a completely randomized design (CRD) with four replications at doses: 0, 50, 75, 100, 125, 150, 175, and 200 Gy using 50 individuals of M. sanborni in each replication. A sublethal dose test and evaluation of their effects on flower quality were performed by using CRD. The dosages used were 0, 200, 225, and 250 Gy with six replications. Data obtained showed that temperature on 28–34 oC dan RH 52–95% resulted in the shorter stadium of M. sanborni nymphs, longer of adult longevity, and higher fecundity rates of M. sanborni than rearing on temperature 27 0C and RH 33-35%. A preliminary test showed that the value of LD99 is 1092.982 Gy in adult. Radiotolerance of C. morifolium cv. Jimba Lima with doses below 300 Gy. Therefore, a sublethal dose test was performed because of the high lethal dose. Dose 200 Gy is the effective dose of gamma irradiation [60Co] against M. sanborni. Application of this dose on the first nymph showed the survival development reached until third nymph and it reached infertile adult when applicated on second, third, and fourth nymphs. Application on adult showed that it still can reproduce first progenies but in small amount and the survival development reached the first nymph. The sublethal dose of gamma irradiation (200 Gy) did not cause damage to the quality of chrysanthemum cut flower (C. morifolium cv. Jimba Lima) until 9 days.