Effect of Radiation Gamma Co-60 on Sterile Male Technique Competitiveness in Inhibiting Population of Rattus argentiventer

Increased rice field rat population in nature, due to birth (natality). One of the innovations that can inhibit the increase in wetland rat populations is the use of sterile male techniques (SMT) using Gamma Co-60 radiation as one of the components in integrated rat pest control systems (IRPCS). This study was designed in a randomized block design (RBD) with 7 radiation dose treatments. Start by mating radiation male rat (?P) with fertile female rat (?F) with treatments ?(P0) × ?(F), ?(P1) × ?(F), ?(P2) × ?(F), ?(P3) × ?(F), ?(P4) × ?(F), ?(P5) × ?(F) and ?(P6) × ?(F), each of which is repeated 5 times. The results of mating between radiation male rats with fertile female rats show that the greater the radiation dose received by radiation male rats, the fewer number of children born by fertile female rats. Statistical analysis shows that doses of 1 and 2Gy, the probability value of P <0.05 significantly decreases the number of pups in control. But at radiation doses 3, 4, 5 and 6Gy no longer significantly decreased the number of pups. Starting from 3Gy doses to 6Gy fertile female rats do not give birth to infants or male rats have experienced infertility. The infertility index was 33.33% at a dose of 1Gy, 77.78% at a dose of 2Gy and 100% for a dose of 3,4,5 and 6Gy. The minimum dose for spaying male rice field rats occurs at a dose of 3Gy. Control of the rat population can be achieved if the male infertile that is released has a 100% infertility index, but it is necessary to take into account the possibility that suppression of rice field rat in the release area can be achieved by releasing radiation male rat that is not 100% sterile but have good mating competitiveness. The radiation dose of 1Gy the marital competitiveness is 0.50, 2 Gy is 0.83 and at a dose of 3Gy, the mating competitiveness is only 0.04. The 2Gy dose with mating competitiveness of 0.83 is the right radiation dose to inhibit the population of rice field rat, although the infertility index is not 100% but has good mating competitiveness. The value of mating competitiveness or C-Index using the index to determine the number of infertile male rats to be released into the area. At a dose of 2Gy obtained a competitive C-Index of 0.83. This means the ratio of infertile male rats and fertile rats is 8 to 1 at the time of release in nature so that it can effectively reduce the population of the wet rat.