Analysis of the growth, productivity and nutritional content of jarak towo variety cassava at various fertilizers and altitudes in Karanganyar Regency, Indonesia

Pengembangan singkong Jarak Towo meningkatkan ketersediaan bahan baku olahan pangan dan pendapatan petani. Hal ini karena keunggulan rasa dan tekstur halus dengan harga mencapai 3 sampai 4 kali lipat dari varietas lain. Sebagai bahan baku industri pengolahan pangan, harus didukung dengan kandungan gizi yang berkualitas. Penelitian ini bertujuan untuk mengetahui produktivitas, parameter pertumbuhan, kandungan gizi singkong Jarak Towo dengan perlakuan dosis pupuk P dan K serta ketinggian tempat yang berbeda. Penelitian ini menggunakan percobaan rancangan acak kelompok lengkap dengan faktorial kombinasi dosis pupuk P dan K. Dosis pupuk P tiga level berupa SP36 yaitu 0 kg ha-1, 100 kg ha-1, dan 200 kg ha-1, sedangkan dosis pupuk K berupa KCl tiga level yaitu 0 kg ha-1, 150 kg ha-1, 300 kg ha-1 sehingga diperoleh sembilan kombinasi perlakuan yang diulang di tiga lokasi yaitu Desa Kemuning, Sepanjang, dan Wonorejo pada ketinggian 700 mdpl, 927 mdpl, and 1034 mdpl. Hasil penelitian menunjukkan bahwa singkong Jarak Towo yang dibudidayakan di Desa Kemuning memiliki kadar air dan lemak tertinggi 54,28 ± 2,76% dan 0,78 ± 0,21%. Kandungan karbohidrat dan protein tertinggi diperoleh di Desa Wonorejo 15,74 ± 4,25% dan 2,42 ± 0,23%. Perlakuan pupuk P dan K tidak berpengaruh signifikan terhadap parameter pertumbuhan, produktivitas dan nutrisi dalam singkong Jarak Towo. ABSTRACT The development of Jarak Towo cassava increases the availability of processed food raw materials and farmers' income. This is because of the superiority of taste and smooth texture with prices reaching 3 to 4 times that of other varieties. As a raw material for the food processing industry, it must be supported by quality nutritional content. This study aimed to determine productivity, the growth parameters, nutritional content of Jarak Towo cassava with different doses of P and K fertilizers and altitudes. This research used a completely randomized block design trial with a factorial combination of P and K fertilizer doses. The dose of P fertilizer at three levels in the form of SP36 was 0 kg ha-1, 100 kg ha-1, and 200kg ha-1, while the dose of K fertilizer in the form of KCl 3 levels was 0 kg ha-1, 150 kg ha-1, 300 kg ha-1 in order to obtain nine treatment combinations repeated in three locations, namely Kemuning, Sepanjang, and Wonorejo Villages at an altitude of 700 masl, 927 masl, and 1034 masl. The results showed that Jarak Towo cassava cultivated in Kemuning Village had the highest water content and fat content of 54.28 ± 2.76% and 0.78 ± 0.21%. The highest carbohydrate and protein content were obtained in Wonorejo Village 15.74 ± 4.25% and 2.42 ± 0.23%. The treatment of P and K fertilizers had no significant effect on the growth parameters, productivity and nutrition in Jarak Towo cassava.