<p>ABSTRAK<br />Jamur entomopatogen Beauveria bassiana sangat potensial<br />mengendalikan berbagai serangga hama, namun potensinya terhadap<br />penggerek buah kapas (Helicoverpa armigera) belum banyak diteliti.<br />Tujuan penelitian adalah untuk mengetahui efektivitas B. bassiana<br />terhadap H. armigera. Penelitian dilakukan di Laboratorium Patologi<br />Serangga dan Kebun Percobaan Karangploso, Balai Penelitian Tanaman<br />Pemanis dan Serat mulai Januari hingga Desember 2012. Penelitian terdiri<br />atas dua kegiatan di lapangan, yaitu (1) uji efektivitas B. bassiana terhadap<br />H. armigera di pot, dan (2) uji efektivitas B. bassiana terhadap H.<br />armigera di lapangan. Kegiatan pertama terdiri dari delapan perlakuan<br />konsentrasi B. bassiana, yaitu: (1) 3,7 x 10 4 ; (2) 7,7 x 10 4 ; (3) 1,2 x 10 5 ;<br />(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<br />konidia/ml; dan (9) kontrol. Perlakuan disusun dalam Rancangan Acak<br />Kelompok dengan 3 kali ulangan. Parameter yang diamati adalah<br />mortalitas dan bobot larva hidup. Kegiatan kedua terdiri dari empat<br />perlakuan konsentrasi B. bassiana, yaitu: (1) 3,1 x 10 11 ; (2) 6,2 x 10 11 ; (3)<br />9,3 x 10 11 ; dan (4) 1,2 x 10 12 konidia/ha dengan dua pembanding<br />(azadirachtin dan betasiflutrin), serta kontrol. Perlakuan disusun dalam<br />Rancangan Acak Kelompok dengan tiga kali ulangan. Parameter yang<br />diamati adalah populasi larva H. armigera dan laba-laba, kerusakan buah<br />kapas, dan hasil kapas berbiji. Hasil uji efektivitas di pot menunjukkan<br />hingga hari ke-7 setelah perlakuan B. bassiana masih efektif menyebabkan<br />mortalitas larva H. armigera sebesar 46,7% dan meningkatkan kehilangan<br />bobot larva hidup hingga 59,3%, terutama pada konsentrasi 2,3 x 10 5<br />konidia/ml. Di lapangan, perlakuan jamur B. bassiana efektif menurunkan<br />populasi larva H. armigera sekitar 36-48%, tetapi menurunkan populasi<br />laba-laba hingga 48,4%, sehingga kurang aman bagi musuh alami tersebut.<br />Perlakuan B. bassiana dapat menurunkan kerusakan buah kapas 10,1-<br />10,3% dengan meningkatkan hasil kapas berbiji sekitar 12,1-29,7%.<br />Kata kunci: Beauveria bassiana, Helicoverpa armigera, konidia, larva,<br />mortalitas</p><p>ABSTRACT<br />Beauveria bassiana is the most common fungal entomopathogen<br />against several of insect pests. Its potency, however, has not been tested on<br />cotton bollworm, H. armigera. The objective of study was to know the<br />effectivity of B. bassiana against H. armigera. This study had been<br />conducted at Pathology Laboratory and Experimental Station of<br />Indonesian Sweetener and Fiber Crops Research Institute (ISFCRI) from<br />January to December 2012. The study consists of two field tests, e.g. test<br />on B. bassiana effectivity against H. armigera (polybag testing) dan test<br />on B. bassiana effectivity a against H. armigera (field testing). In polybag<br />testing, eight concentrations of B. bassiana and one control were used as<br />treatment, 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)<br />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)<br />control. Each treatment was arranged in Randomized Block Design with<br />three replications. Parameters recorded were mortality and weight of<br />survival larvae. The field testing consists of four concentrations of B.<br />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/ha<br />which compared to azadirachtin and betacyfluthrin. Each treatment was<br />arranged in Randomized Block Design with three replications. Parameter<br />observed were population of H. armigera larvae and its natural enemy<br />(spiders), boll damage, and seed cotton yield. Result showed that until the<br />day seventh the mortality of H. armigera larvae reached 46.7% due to B.<br />bassiana and loss 59.3% of larval weight at 2,3 x 10 5 conidia/ml in<br />polybag testing. In field testing, B. bassiana proved to be relatively<br />harmful to spiders because it reduced the their population as 48.4%.<br />However, the B. bassiana reduced of 36-48% the population of H.<br />armigera larvae as well as the cotton boll damage of 10.1-10.3% and<br />increased the seed cotton yield ranged 12.1-29.7%.<br />Key words: Beauveria bassiana, Helicoverpa armigera, conidia, larvae,<br />mortality</p>
Study on Heterosis for Yield and Yield Contributing Traits in Desi Cotton (Gossypium arboreum L.)
