<p>ABSTRAK<br />Rekomendasi cara pengendalian hama pengisap daun, Amrasca<br />biguttula (ISHIDA) pada tanaman kapas masih mengandalkan<br />penggunaan kombinasi varietas tahan dan perlakuan benih dengan<br />insektisida kimia sistemik imidakloprid. Namun, tidak jarang petani<br />melakukan penyemprotan insektisida kimia pada kanopi tanaman yang<br />juga dapat membunuh serangga berguna, termasuk musuh alami. Tujuan<br />penelitian adalah untuk mengetahui keefektifan teknik pengendalian A.<br />biguttula pada kapas menggunakan varietas dan insektisida. Penelitian<br />dilakukan di KP Asembagus mulai Januari sampai dengan Nopember<br />2010. Perlakuan petak utama, yaitu teknik pengendalian: (1) perlakuan<br />benih dengan imidakloprid (PB), (2) tanpa perlakuan benih maupun<br />penyemprotan kanopi tanaman atau kontrol (TPB), (3) perlakuan benih +<br />penyemprotan kanopi (PBS), dan (4) penyemprotan kanopi (S). Perlakuan<br />anak petak adalah tiga galur/varietas kapas, yaitu: (1) galur 98050/9/2/4,<br />(2) KI 645, dan (3) Kanesia 10. Pola tanam yang diterapkan adalah<br />tumpangsari kapas dan kacang hijau yang ditanam di antara baris kapas.<br />Setiap perlakuan disusun dalam rancangan petak terbagi dengan tiga kali<br />ulangan. Ukuran anak petak adalah 10 m x 15 m. Pengamatan dilakukan<br />terhadap (1) populasi nimfa A. biguttula dan predatornya, (2) frekuensi<br />pencapaian populasi ambang ekonomi, (3) skor kerusakan tanaman kapas,<br />(4) hasil kapas berbiji dan kacang hijau, dan (5) analisis ekonomi<br />perlakuan. Hasil penelitian menunjukkan bahwa setiap teknik<br />pengendalian yang diuji berpengaruh terhadap perkembangan populasi A.<br />biguttula dan predatornya. Rata-rata pencapaian populasi ambang<br />ekonomi pada perlakuan benih (PB) dan kontrol lebih rendah (0,5–2 kali)<br />dibandingkan dengan kombinasi perlakuan benih dan penyemprotan<br />kanopi (PBS) serta penyemprotan kanopi saja (S) yang mencapai 3–4 kali.<br />Pada galur/varietas kapas yang diuji, pencapaian populasi ambang<br />ekonomi paling rendah terjadi pada galur 98050/9/2/4, diikuti oleh Kanesia<br />10 dan KI 645. Perlakuan benih saja (PB) selain menurunkan populasi A.<br />biguttula dan tidak menurunkan populasi predator, juga lebih efisien<br />dibanding perlakuan lainnya dengan nilai marginal rate of return 1,38 dan<br />peningkatan bersih 14,3%. Makna dari hasil yang diperoleh adalah<br />pengendalian A. biguttula pada kapas dengan cara menyemprot kanopi<br />lebih baik dihindari apabila benih masih dapat diperlakukan, sedapat<br />mungkin dikombinasikan dengan penggunaan varietas tahan/toleran.<br />Kata kunci : Amrasca biguttula, imidakloprid, ambang ekonomi, galur/<br />varietas, kapas, predator, marginal rate of return (MRR)</p><p>ABSTRACT<br />Effectiveness and Efficiency of Different Control<br />Techniques of Cotton Jassid, Amrasca biguttula<br />Recommendation for controlling jassid (A. biguttula) of cotton still relies<br />on the use of combination of resistant variety and seed treatment<br />(imidachloprid). Farmers, however, often spray chemical insecticides over<br />plant canopy that also kill beneficial insects, including natural enemies.<br />This study was conducted at Asembagus Experimental Station from<br />January to November 2010. The objective of the study was to find out the<br />effectiveness and efficiency of control techniques against cotton jassid, A.<br />biguttula. This field study consisted of two factors. First factor consisted<br />of three different control techniques i.e. (1) seed treatment (PB), (2)<br />without seed treatment and foliar application or control (TPB), (3)<br />combination between seed treatment and foliar application (PBS), and (4)<br />foliar application alone (S). Second factor consisted of three cotton<br />varieties, e.g. 98050/9/2/4, KI 645, and Kanesia 10. Treatments were<br />arranged in a split plot design with three replicates. Cotton intercropped<br />with mung bean planted in between cotton rows. Population of A. biguttula<br />and its predator, economic threshold achievement, score of plant injury,<br />yields of cotton and mung bean were observed. Economic analysis of the<br />treatments was evaluated at the end of the experiment. Results showed that<br />each control techniques caused different effect on jassid and its predator<br />development. The average of economic threshold achievement in seed<br />treatment application (PB) and control (TPB) were lower (0.5-2.0 times)<br />compared to combination between seed treatment and foliar sprayed<br />(PBS), also only foliar sprayed (3-4 times). Averaged of economic<br />threshold achievement on 98050/9/2/4 line was the lowest, followed by<br />Kanesia 10 and KI 645. Application of seed treatment (PB) not only<br />reduced jassid population but also less effective on predator population. It<br />was more efficient than other treatments with marginal rate 1.38 and did<br />increase net income by 14.3%. It means that foliar sprays to control A.<br />biguttula on cotton should be ignored, if applying seed treatment and<br />resistant/tolerant varieties.<br />Key words: Amrasca biguttula, imidachloprid, economic threshold,<br />cotton cultivar/variety, predator, marginal rate of return<br />(MRR)</p>
Interactive effects of crop variety, insecticide seed treatment, and planting date on population dynamics of sugarcane aphid (Melanaphis sacchari) and their predators in late-colonized sorghum