Respons Pertumbuhan dan Hasil Tanaman Selada (Lactuca sativa L.) Terhadap Formulasi dan Konsentrasi Larutan Hara Pada Sistem Hidroponik Rakit Apung

Abstract

Tanaman selada (Lactuca sativa L.) merupakan salah satu sayuran daun yang banyak dibudidayakan secara hidroponik karena memiliki nilai ekonomi tinggi dan permintaan pasar yang terus meningkat. Keberhasilan budidaya hidroponik sangat dipengaruhi oleh formulasi hara dan konsentrasi larutan hara yang digunakan. Penelitian ini bertujuan menganalisis pengaruh formulasi hara, konsentrasi electrical conductivity (EC), serta interaksi keduanya terhadap pertumbuhan dan hasil tanaman selada pada sistem hidroponik rakit apung. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor, Jawa Barat, pada Juni–September 2024 menggunakan Rancangan Acak Lengkap (RAL) faktorial. Faktor pertama adalah formulasi hara yang terdiri atas Hoagland Solution, Howard Resh, Sapkota et al. (2019), dan Douglas Peckenpaugh, sedangkan faktor kedua adalah konsentrasi EC 1,5, 2,0, 2,5, dan 3,0 mS/cm. Namun, formulasi Sapkota et al. (2019) tidak dapat dianalisis lebih lanjut karena tingginya mortalitas tanaman. Hasil penelitian menunjukkan bahwa formulasi hara berpengaruh sangat nyata terhadap tinggi tanaman, jumlah daun, bobot basah tajuk, bobot basah akar, dan bobot total tanaman. Formulasi Howard Resh dan Douglas Peckenpaugh menghasilkan bobot total tanaman tertinggi masing-masing sebesar 34,81 g dan 34,84 g. Konsentrasi EC berpengaruh sangat nyata terhadap seluruh variabel hasil dan menunjukkan respons kuadratik pada beberapa parameter pertumbuhan. Konsentrasi EC optimum untuk tinggi tanaman diperoleh pada 1,86 mS/cm dengan prediksi tinggi tanaman 47,9 cm, sedangkan konsentrasi EC optimum untuk bobot basah akar diperoleh pada 2,28 mS/cm. Interaksi antara formulasi hara dan konsentrasi EC berpengaruh sangat nyata terhadap bobot basah tajuk, akar, batang, dan bobot total tanaman. Hasil penelitian menunjukkan bahwa formulasi Howard Resh dan Douglas Peckenpaugh dengan konsentrasi EC sekitar 1,8–2,3 mS/cm berpotensi menghasilkan pertumbuhan dan produktivitas selada yang lebih baik pada sistem hidroponik rakit apung.

Lettuce (Lactuca sativa L.) is one of the most widely cultivated leafy vegetables in hydroponic systems due to its high economic value and increasing market demand. The success of hydroponic cultivation is strongly influenced by nutrient formulation and nutrient solution concentration. This study aimed to evaluate the effects of nutrient formulations, electrical conductivity (EC) levels, and their interaction on the growth and yield of lettuce cultivated in a floating raft hydroponic system. The experiment was conducted at the Leuwikopo Experimental Farm, IPB University, Dramaga, Bogor, West Java, Indonesia, from June to September 2024 using a factorial Completely Randomized Design (CRD). The first factor consisted of four nutrient formulations, namely Hoagland Solution, Howard Resh, Sapkota et al. (2019), and Douglas Peckenpaugh, while the second factor consisted of four EC levels: 1,5, 2,0, 2,5, and 3,0 mS/cm. However, the Sapkota et al. (2019) formulation was excluded from further analysis due to high plant mortality. The results showed that nutrient formulation had a highly significant effect on plant height, number of leaves, shoot fresh weight, root fresh weight, and total plant fresh weight. The Howard Resh and Douglas Peckenpaugh formulations produced the highest total plant fresh weights of 34.81 g and 34.84 g, respectively. EC concentration significantly affected all yield variables and exhibited quadratic responses in several growth parameters. The optimum EC for plant height was 1.86 mS/cm, with a predicted plant height of 47.9 cm, whereas the optimum EC for root fresh weight was 2.28 mS/cm. The interaction between nutrient formulation and EC concentration had a highly significant effect on shoot fresh weight, root fresh weight, stem fresh weight, and total plant fresh weight. These findings indicate that the Howard Resh and Douglas Peckenpaugh formulations combined with EC levels ranging from approximately 1.8 to 2.3 mS/cm have the potential to enhance lettuce growth and productivity in a floating raft hydroponic system.