Agronomics and chemicals properties of tobacco under different planting dates of sorghum in tobacco and sorghum intercropping system

English. The field experiment was conducted at Pakuwon Experimental Station, Bojonegara, in 1992, to study the agronomic and chemical properties of tobacco grown under different planting dates of sorghum in tobacco + sorghum intercropping system. The experiment was arranged in randomized block design, with 6 replications. The treatment consisted of 5 levels of sorghum planting, 2 and 4 weeks after tobacco planting. Plot size was 10.8 m x 12.0 m, with 240 and 720 plants of tobacco and sorghum respectively. The methods for analyses N, P, K, nicotine and sugar analyses were Kyeldhal, Spectrophometry, Flame photometry, Titration with NaOH, and Luff-Schroll, respectively. The growth, yield, and quality of tobacco were decreased sharply, but the N, P, K contents of the leaves were increased by accelerating planting date of sorghum from 4 weeks after to 4 weeks before tobacco planting. The content of nicotine, sugar, sugar/nicotine N nicotine of the leaves were not affected by this treatment. In dry condition, although the yield of tobacco was low, but the quality was in good category, and the competition in tobacco + sorghum intercropping system was dominated by sorghum.

English. Percobaan lapang telah dilakukan di Kebun Percobaan Pakuwon, Bojonegara, 1992, untuk mempelajari sifat-sifat agronomis dan kimiawi tembakau pada berbagai waktu tanam sorgum pada sistem tumpangsari tembakau + sorgum. Percobaan disusun dalam rancangan acak kelompok dengan enam ulangan. Perlakuan terdiri dari 5 taraf waktu tanam sorgum yaitu 4 dan 2 minggu setanam tembakau belum bersamaan dengan waktu tanam tembakau, 2 dan 4 minggu setelah tanam tembakau. Ukuran petak 10.8 m x 12.0 m, dengan 240 tanaman tembakau per petak dan 720 tanaman sorgum per petak. Analisis N, P, K, nikotin, dan gula berturut-turut dengan Kyeldhal, Spektrofotometri, Flamefotometri, Titrasi dengan NaOH dan Luff-Schroll. Hasil percobaan menunjukkan bahwa dengan mempercepat waktu tanam sorgum dari 4 minggu setelah tanam tembakau menjadi 4 minggu sebelum tanam tembakau sangat menurunkan pertumbuhan, hasil dan mutu. Sebaliknya perlakuan tersebut meningkatkan kadar N-total, P, dan K, dan hasil sorgum tumpangsari, serta tidak berpengaruh pada kadar nikotin, gula, nisbah/nikotin, dan N/nikotin tembakau. Pada keadaan kering yang dialami oleh percobaan ini walaupun hasil pembakau rendah namun mutu hasil masih dalam kisaran yang baik dan persaingan dikuasai oleh tanaman sorgum.