EFEKTIVITAS FORMULA JAMUR Beauveria bassiana DALAM PENGENDALIAN PENGGEREK BUAH KAPAS (Helicoverpa armigera) - INDRAYANI, IGAA.; SOETOPO, DECIYANTO; HARTONO, JOKO (853-8212)
ABSTRAKJamur entomopatogen Beauveria bassiana sangat potensialmengendalikan berbagai serangga hama, namun potensinya terhadappenggerek buah kapas (Helicoverpa armigera) belum banyak diteliti.Tujuan penelitian adalah untuk mengetahui efektivitas B. bassianaterhadap H. armigera. Penelitian dilakukan di Laboratorium PatologiSerangga dan Kebun Percobaan Karangploso, Balai Penelitian TanamanPemanis dan Serat mulai Januari hingga Desember 2012. Penelitian terdiriatas dua kegiatan di lapangan, yaitu (1) uji efektivitas B. bassiana terhadapH. armigera di pot, dan (2) uji efektivitas B. bassiana terhadap H.armigera di lapangan. Kegiatan pertama terdiri dari delapan perlakuankonsentrasi B. bassiana, yaitu: (1) 3,7 x 10 4 ; (2) 7,7 x 10 4 ; (3) 1,2 x 10 5 ;(4) 1,5 x 10 5 ; (5) 1,9 x 10 5;  (6) 2,3 x 10 5;  (7) 2,5 x 10 5 ; (8) 3,0 x 10 5konidia/ml; dan (9) kontrol. Perlakuan disusun dalam Rancangan AcakKelompok dengan 3 kali ulangan. Parameter yang diamati adalahmortalitas dan bobot larva hidup. Kegiatan kedua terdiri dari empatperlakuan konsentrasi B. bassiana, yaitu: (1) 3,1 x 10 11 ; (2) 6,2 x 10 11 ; (3)9,3 x 10 11 ; dan (4) 1,2 x 10 12 konidia/ha dengan dua pembanding(azadirachtin dan betasiflutrin), serta kontrol. Perlakuan disusun dalamRancangan Acak Kelompok dengan tiga kali ulangan. Parameter yangdiamati adalah populasi larva H. armigera dan laba-laba, kerusakan buahkapas, dan hasil kapas berbiji. Hasil uji efektivitas di pot menunjukkanhingga hari ke-7 setelah perlakuan B. bassiana masih efektif menyebabkanmortalitas larva H. armigera sebesar 46,7% dan meningkatkan kehilanganbobot larva hidup hingga 59,3%, terutama pada konsentrasi 2,3 x 10 5konidia/ml. Di lapangan, perlakuan jamur B. bassiana efektif menurunkanpopulasi larva H. armigera sekitar 36-48%, tetapi menurunkan populasilaba-laba hingga 48,4%, sehingga kurang aman bagi musuh alami tersebut.Perlakuan B. bassiana dapat menurunkan kerusakan buah kapas 10,1-10,3% dengan meningkatkan hasil kapas berbiji sekitar 12,1-29,7%.Kata kunci: Beauveria bassiana, Helicoverpa armigera, konidia, larva,mortalitasABSTRACTBeauveria bassiana is the most common fungal entomopathogenagainst several of insect pests. Its potency, however, has not been tested oncotton bollworm, H. armigera. The objective of study was to know theeffectivity of B. bassiana against H. armigera. This study had beenconducted at Pathology Laboratory and Experimental Station ofIndonesian Sweetener and Fiber Crops Research Institute (ISFCRI) fromJanuary to December 2012. The study consists of two field tests, e.g. teston B. bassiana effectivity against H. armigera (polybag testing) dan teston B. bassiana effectivity a against H. armigera (field testing). In polybagtesting, eight concentrations of B. bassiana and one control were used astreatment, e.g. (1) 3.7 x 10 4 ; (2) 7.7 x 10 4 ; (3) 1.2 x 10 5 ; (4) 1.5 x 10 5 ; (5)1.9 x 10 5;  (6) 2.3 x 10 5;  (7) 2.5 x 10 5 ; (8) 3.0 x 10 5  conidia/ml; and (9)control. Each treatment was arranged in Randomized Block Design withthree replications. Parameters recorded were mortality and weight ofsurvival larvae. The field testing consists of four concentrations of B.bassiana viz. 3.1 x 10 11 ; 6.2 x 10 11 ; 9.3 x 10 11 ; and (4) 1.2 x 10 12 conidia/hawhich compared to azadirachtin and betacyfluthrin. Each treatment wasarranged in Randomized Block Design with three replications. Parameterobserved were population of H. armigera larvae and its natural enemy(spiders), boll damage, and seed cotton yield. Result showed that until theday seventh the mortality of H. armigera larvae reached 46.7% due to B.bassiana and loss 59.3% of larval weight at 2,3 x 10 5 conidia/ml inpolybag testing. In field testing, B. bassiana proved to be relativelyharmful to spiders because it reduced the their population as 48.4%.However, the B. bassiana reduced of 36-48% the population of H.armigera larvae as well as the cotton boll damage of 10.1-10.3% andincreased the seed cotton yield ranged 12.1-29.7%.Key words: Beauveria bassiana, Helicoverpa armigera, conidia, larvae,mortality