Abstract:This trial was aimed to evaluate the performance of sweet potato cultivars on biochar application. The treatments were carried out using a Split-plot Design with three replications. The cultivars were placed on main plots and biochar doses were on sub-plots. The thirteen cultivars consisted of seven varieties and six accessions from Tribhuwana Tunggadewi University and Brawijaya University collections. The applied biochar doses were B 0 (0 t/ha) and B 1 (5 t/ha). The experimental unit measuring of 5 m x 0.6 m consisted of single row and planted with a spacing of 25 cm in row or 20 cuttings/row. The storage root weight, % dry matter, storage root dry weight, dry weight of biomass, harvest index and yield estimation were determined. The results showed that the sweet potato cultivars gave a significant response to the biochar application on fresh storage root weight, storage root dry weight, biomass dry weight, harvest index and storage root yields, but no interaction between cultivars and biochar doses. Storage root yield ranged from 8 to 21 t/ha without biochar and from 10 to 23 t/ha with 5 t biochar /ha, except for Beta 1 and Boko. The use of 5 t biochar /ha increased storage root yields that ranged from 8 to 45%. Keywords: biochar from tobacco industry waste, sweet potato, storage root fresh weightTo cite this article: Indawan, E., Lestari, S.U. and Thiasari, N. 2018. Sweet potato response to biochar application on sub-optimal dry land.

Sweet potato is a dual-purpose crop, which could produce both food and feed. The vine pruning prior to storage root harvesting was intended to increase the quantity and quality of fresh forage for animal feed. This study aims to evaluate whether periodic pruning can affect the storage root yield and its starch content. This experiment employed split-plot design with two factors and three replications. The first factor as main plot was vine pruning which consisted of four distinct pruning times (four times, three times, twice and once). The second factor as sub-plot was cultivars which consisted of six dual-purpose cultivars and two controls. The storage root yields, vine yields, starch yields and the reduction in storage root yields were observed. The results showed that the vine pruning decreased the storage root yields, with small increases the vine yields. The percentage of the reduction in storage root yields were 4-58%, while the decrease vine yields are relatively inconsistent. The starch yield of the cultivars with one pruning time were in the range of 2.34-6.67 ton ha^-1. On the contrary, the three times pruning or more since 80 days after transplanted can reduce the starch yields for more than 50%. The slight increase in vines yield due to pruning was followed by the decrease in storage root yields and starch content of the sweet potato.

ABSTRACT:The study aimed to investigate the effect of protein level in the complete feed based on fermented banana pseudostem(CFFBP) on in vitro digestibility. The experiment was conducted from May to August 2016. CFFBP was made at the field laboratory of Tribhuwana Tunggadewi University, Malang. Proximate and in vitro digestibility analysis was carried out at the Animal Nutrition Laboratory, the Faculty of Animal Husbandry, Brawijaya University. The experiment used Completely Randomized Design with 3 treatments and 5 replications. The treatments were P 1 CFFBP at protein level 12%; P 2 CFFBP at protein level 14%; P 3 CFFBP at protein level 16%. The results showed that digestibility of dry matter (DMD), digestibility of organic matter (OMD) and Total Digestible Nutrient (TDN) were significantly affected by the treatments (P<0.01). The highest digestibility of DMD, of OMD and TDN was found at CFFBP with protein level 14%. The DMD value were P 1 71.56%, P 2 75.06% and P 3 74.32%. The OMD value were P 1 65.53%, P 2 68.50% and P 3 69,82%. The TDN value were P 1 61.84%, P 2 66.07% and P 3 64.91%. The experiment concluded that the increasing level of protein in the CFFBP could increase DMD, OMD and TDN, and it was related to the availability of protein and energy ratio. The ideal level of protein in this experiment was 14%.

The experiment was conducted to evaluate the effect of different pruning intervals on nutrient composition and yield of vines from seven sweet potato cultivars. Treatments were arranged in a split-plot design with three replications. The pruning intervals were 80, 90, 120, and 150 days after planting as the main-plots and the trimming volume of sweet potato vine was 25%. Seven sweet potato cultivars (Kuningan Putih, Beta 2, Kuningan Merah, BIS OP-61, 73 OP-5, BIS OP-61-♀-29 and BIS OP-61-OP-22) were in the sub-plots and allocated at random. Results showed that increasing the pruning intervals increased dry matter, organic matter, and crude fiber significantly. However, ash and crude protein were decreased as the trimming intervals increased. Eter Extract was unaffected by trimming intervals.

Tuntutan peningkatan sumber protein hewani terutama daging unggas menuntut ketersediaan pakan yang kontinyu, salah satunya adalah pemanfaatan limbah sayur pasar. Limbah ini jumlahnya banyak setiap harinya dan masih banyak yang belum termanfaatkan bahkan cenderung menimbulkan pencemaran lingkungan. Tujuan penelitian ini adalah mencari level terbaik penggunaan limbah sayur sebagai pakan ayam broiler yang memberikan peningkatan terhadap penampilan produksi dan kondisi microflora yang baik. Metode penelitian adalah menggunakan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan yaitu P1 (pakan control tanpa limbah sayur), P2 (penggunaan 5% limbah sayur dalam 100% formulasi pakan), P3 (penggunaan 10% limbah sayur dalam 100% formulasi pakan), P3 (penggunaan 15% limbah sayur dalam 100% formulasi pakan), dan P4 (penggunaan 20% limbah sayur dalam 100% formulasi pakan). Parameter yang diamati terdiri dari 2 kelompok yaitu terhadap penampilan produksi dan kondisi microflora usus. Hasil penelitian menghasilkan penggunaan pakan crumble ayam broiler berbasis limbah sayur memberikan pengaruh yang sangat nyata terhadap konsumsi, FCR, total TPC (p<0.01), serta peningkatan terhadap bobot badan dan jumlah bakteri asam laktat (BAL) dibandingkan dengan control. Penggunaan proporsi 15% limbah sayur memberikan peningkatan tertinggi terhadap konsumsi, pertambahan bobot badan, dan penurunan FCR, dan peningkatan terhadap BAL.