ANALISIS LINTAS SIFAT-SIFAT AGRONOMIS TERHADAP INDEKS TANAMAN DAN KADAR NIKOTIN TEMBAKAU VIRGINIA BOJONEGORO - . ADJISASTROSUPADI; A. S. MURDIYATI (Jurnal Penelitian Tanaman Industri, 2004)
Hubungan sifat-sifat agronomis terhadap indeks tanaman dan kadar nikotin telah dicari dengan analisis lintas. Tujuan dari analisis adalah untuk mengetahui pcubah bebas yang sangat mempengaruhi peubah yang tidak bebas, indeks mutu dan kadar nikotin daun, sehingga dapat mengurangi banyaknya pengamatan yang dilakukan. Data pengamatan agronomis yang meliputi : jumlah daun/pohon, luas daun ke-7, luas daun ke-15, bobot rajangan kering/ha, indeks mutu dan indeks tanaman diperoleh dari percobaan pemupukan tiga galur harapan tembakau Virginia di kebun percobaan Pekuwon Bojonegoro dari bulan Mei sampai dengan Oktober 2002. Hasil analisis lintas antara indeks tanaman dengan peubah bebas di atas menunjukkan bahwa indeks tanaman sangat ditentukan oleh bobot rajangan kering dengan koefisien lintas pm-1.03367 dan koefisien dcterminasi parsial 102%. Hubungan lintas bcrantai melalui pcubah rajangan kering dan indeks mutu menunjukkan bahwa luas daun kc-7 sangat mempengaruhi rajangan kering dengan koefisien lintas (p„i)- 0.85257 dan rajangan kering sangat mempengaruhi indeks tanaman dengan koefisien lintas (p,x,)= 0.95639, indeks mutu pengaruhnya terhadap indeks lanaman sangat kecil dengan koefisien lintas p,M = 0.12316. Analisis lintas antara kadar nikotin daun dengan ke lima peubah tidak baik (unfit) dengan koefisien sisa p„,= 0.6827 melebihi koefisien lintas yang lainnya. Dengan pentingnya peubah rajangan kering ini maka penjualan daun segar yang dilakukan oleh petani tidak dianjurkan.Kata kunci: Nicotiana tabacum, tembakau Virginia, analisis lintas, jumlah daun, luas daun, indeks tanaman, indeks mutu, kadar nikotin, bobot rajangan ABSTRACT Path analysis of agronomical characteristics on crops index and nicotine content of Virginia tobacco Bojonegoro The relationship between agronomical characteristics and crops index or leaf nicotine content has been studied by using path analysis. The purpose of this analysis was to determine the independent variables which most affected the dependent ones as crops index and leaf nicotine contain, so that it could reduce the number of independent variables. The agronomical characteristics consist of leaf number/plant, seventh and fiteenth leaf area, dried slice leaf/ha, grade index and crop index obtained from fetilizer experiment on three Virginia tobacco lines at Pekuwon Experimental Garden Bojonegoro, from May to October 2002. The results of this path analysis showed that crop index was strongly affected by dried slice leaf with path coeficient poi = 1.03367 and patial determination coefficient 102%. It was indicated that dried slice leaf was strongly affected by seventh leaf area with path coefficient p,n- 0.85257 and dried slice leaf strongly variable affected the crop index with path coeficient poi= 0.95639, while the grade index had little effect on crop index with path coefficient poi= 0.12316. The path analysis between leaf nicotine content and ive variables above was unfit with residual path coeficient pou= 0.6827, it was higher than each path coefficient of the orther variables. The dried slice leaf was the main independent variable affecting the crops index, so that selling of fresh tobacco leaves by farmers is not recomended.Key words : Nicotiana tabacum, Virginia tobacco, path analysis, leaf number, leaf area, crop index, grade index, nicotine content, dried slice leaf