PENGARUH PUPUK K TERHADAP PERTUMBUHAN, HASIL DAN MUTU RIMPANG JAHE MUDA (Zingiber officinale Rocs.)
Authors: RAHARDJO MONO 
Published: June 2020

ABSTRAK<br />Kalium merupakan unsur hara yang paling banyak diserap oleh<br />tanaman jahe dibandingkan N dan P. Produktivitas tanaman akan menurun<br />apabila kekurangan unsur hara K, karena K mempunyai fungsi penting<br />pada proses fotosintesis, aktifitas enzim, metabolisme karbohidrat, protein<br />dan sebagai transport ion. Penelitian dilakukan di Kebun Percobaan<br />Sukamulya sejak Januari sampai Mei 2010. Tujuan penelitian ini adalah<br />untuk mengetahui pengaruh pemberian pupuk KCl terhadap pertumbuhan,<br />hasil, serapan hara, dan mutu rimpang jahe muda. Perlakuan disusun<br />dalam rancangan acak kelompok dan diulang 4 kali. Perlakuan yang<br />dicoba terdiri atas delapan perlakuan pupuk KCl yaitu; 0, 50, 100, 150,<br />200, 250, 300, dan 350 kg/ha. Jarak tanam yang digunakan adalah 50 x 60<br />cm, dengan populasi 100 tanaman/plot. Contoh tanaman diambil pada<br />umur 4 BST, sebanyak 5 tanaman setiap satuan perlakuan. Peubah yang<br />diamati adalah, tinggi tanaman, jumlah anakan, bobot segar rimpang,<br />bobot kering rimpang dan tanaman, kadar minyak atsiri, pati, serat, hara<br />N, P dan K. Hasil penelitian menunjukkan bahwa tinggi tanaman, bobot<br />segar rimpang, bobot kering batang+daun dan bobot kering rimpang<br />meningkat secara nyata dengan meningkatnya perlakuan pupuk KCl.<br />Tinggi tanaman, bobot segar rimpang, bobot kering batang+daun tertinggi<br />dicapai pada perlakuan pupuk KCl dosis 350 kg/ha, masing-masing adalah<br />86,88 cm, 272,51 g/tanaman, dan 27,46 g/tanaman. Peningkatan bobot<br />kering batang+daun dan bobot segar rimpang berkorelasi positif dengan<br />meningkatnya pemupukan KCl sampai dosis 350 kg/ha, membentuk<br />persamaan linier (r = 0,610 tn dan 0,643 tn ) dengan tingkat kepercayaan<br />masing-masing P = 0,987** dan 0,99**. Kadar serat rimpang meningkat<br />membentuk persamaan kuadratik (R 2 = 0,792*) dengan peningkatan<br />pemupukan KCl sampai dosis 350 kg/ha, dengan tingkat kepercayaan P =<br />0,997**. Serapan hara N, P dan K berkorelasi positif dengan peningkatan<br />pemupukan KCl sampai dosis 350 kg/ha. Serapan N membentuk<br />persamaan linier (r = 0,541 tn ) dengan tingkat kepercayaan P = 0,977**,<br />serapan P membentuk persamaan kuadratik (R 2 = 0,798*) dengan tingkat<br />kepercayaan P = 0,992**, dan serapan K membentuk persamaan kuadratik<br />(R 2 = 0,643 tn ) dengan tingkat kepercayaan P = 0,947**.<br />Kata kunci : Zingiber officinale Rocs., pupuk KCl, pertumbuhan, mutu,<br />hasil jahe muda<br /><br />ABSTRACT<br />Potassium is the nutrient most absorbed by ginger compared to N<br />and P nutrients. Crop productivity will decline if it lacks of K nutrient,<br />because K has an important function in the photosynthesis of process,<br />enzyme activity, metabolisms of carbohydrates and proteins, and it also<br />functions as an ion transport. A study, conducted at Sukamulya<br />Experimental Station from January to May 2010, aimed at determining the<br />effect of KCl fertilizer application on growth, yield, nutrient uptake, and<br />quality of young ginger rhizomes. Treatments were arranged in a<br />randomized block design with four replicates. The treatments consisted of<br />eight KCl fertilizer dosages, namely: 0, 50, 100, 150, 200, 250, 300, and<br />350 kg/ha. Planting space used was 50 x 60 cm, with plants population of<br />100/plot. Five plants per treatment unit were sampled at the age of 4<br />months after planting. Variables observed were plant height, number of<br />tillers, rhizome fresh weight, dry weights of rhizomes and plants, contents<br />of essential oil, starch, fiber, and N, P, and K nutrients. The results showed<br />that plant height, rhizome fresh weight, stems + leaf dry weight, and<br />rhizome dry weight increased significantly in line with the increase in KCl<br />fertilizer dosages. The best results of plant height, rhizome fresh weight,<br />and dry weight of stem + leaf were achieved at the highest dosage of KCl<br />fertilizer (350 kg/ha). The measures were 86.88 cm, 272.51 g/plant, and<br />27.46 g/plant, respectively. Increase in dry weights of stem + leaf and<br />fresh rhizome were positively correlated with increasing fertilizer dosages<br />of KCl up to 350 kg/ha, forming a linear equation (r = 0.610 tn and r =<br />0.643 tn ) with P confidence levels of 0.987** and 0.99**, respectively.<br />Increase in fiber content of rhizomes formed a quadratic equation (R 2 =<br />0.792*) by increasing dosages of KCl fertilizer up to 350 kg/ha, with a P<br />confidence level of 0.997**. Uptakes of N, P, and K nutrients were<br />positively correlated with increases in KCl fertilizations up to 350 kg/ha.<br />Uptakes of N nutrient formed a linear equation (r = 0.541 tn ) with a P<br />confidence level of 0.977**, P uptakes formed a quadratic equation (R 2 =<br />0.798*) with a P confidence level of 0.992**, and uptakes of K also<br />formed a quadratic equation (R 2 = 0.643 tn ) with a P confidence level of<br />0.947**.<br />Key words: Zingiber officinale Rocs., KCl fertilizer, growth, quality,<br />young ginger rizhome