The Indonesian sugarcane production in the dryland was not optimal due to physiological stress. The research to improve their physiological characteristics by arbuscular mycorrhizal application was conducted at inceptisol soil from April 2014 to February 2015, using factorial completely randomized design. The first factor was clones PS864, Kidangkencana, PS881, Bululawang, and VMC, whereas the second factor was timing of arbuscular mycorrhizal inoculum applications i.e.: in the field, nursery, and control. The results show that the mycorrhizal application in the nursery significantly increased the infection percentage (41.3%) at the age of 1 week after transplanting to the field. There are differences in physiological and growth performance of clones by the effect of timing of mycorrhizal application. Bululawang with mycorrhizal application in the nursery stage tended to have better physiological performance such as chlorophylls a, b, and total chlorophyll, photosynthesis rate, intercellular CO 2 concentration, leaf area, as well as the weight of stem biomass. Mycorrhizal application in the nursery stage showed the highest increase of net assimilation rate on the PS864 and, BL clones, and the highest crop growth rate on the PS864, KK and BL clones. The mycorrizal inoculum application in the nursery increased the biomass weight of stem (11-61.1%). Infection percentage of mycorrhiza was positively correlated with the biomass weight with r 2 values of 0.54.

The research aims to investigate the effects of silica (Si) as an ameliorant on the proline compound concentration and the growth response of oil palm exposed to aluminum toxicity. The research was arranged in a complete randomized block design with 8 blocks as replications. The first factor was Al toxicity which consisted of two levels as without and with Al toxicity. Al toxicity treatment was applied by giving 300 ppm of Al concentrate along with watering activity regularly. The second factor was the application of silica which consisted of four levels as 0, 32, 64 g/plant. Proline and growth activities of leaf area, plant height, number of leaves, and dry weight were observed in the research. The data subjected to analysis of variance (ANOVA) at 5% test level. If the result of ANOVA showed significant differences among treatments, then the data would have been analyzed by Duncan's Multiple Range Test (DMRT) at 5% test level. The results of the research provide information that Al toxicity increases proline compound in the plant tissues and decreases leaf area, plant height, number of leaves, and dry weight of Oil Palm. Applying Si at the level of 64 g/plant could increase proline concentrate and dry weight of oil palm exposed to A1 toxicity. Proline compound in the plant tissues did not have any correlation with the growth of oil palm. Thus, this case indicated that proline was a product and not a plant tolerant mechanism of Al toxicity.

<p>The need of nitrogen (N), phosphate (P) and potassium (K) nutrient in oil palm nursery are usually fulfilled with synthetic chemical fertilizers such as NPK fertilizer. The application of NPK fertilizer can cause the soil to become hard due to the accumulation of the residue left on the ground. Cow manure is able to substitute NPK fertilizer based on the chemical status of the soil. This study aimed at analyzing the effect of NPK fertilizer substitution with cow manure on the growth of oil palm seedlings in the pre-nurseries and main nurseries. The experiment was conducted from February to September 2018 in the Banguntapan research and experimental field, Faculty of Agriculture, Universitas Gadjah Mada. The experiment applied the Randomized Complete Block Design (RCBD) with one factor and six blocks as replications. The factors were subtitution using the replacement series method with five levels of doses, 100% NPK, 75% NPK + 25% cow manure, 50% NPK + 50% cow manure, 25% NPK + 75% cow manure and 100% cow manure. The observed parameter variables were root lenght, root area, hump diameter, leaf area, the number of leaves, plant height and plant dry matter. The use of 25% NPK substitute with 75% organic material was the best result in increasing the growth performance of oil palm seddlings in pre-nursery and main nursery.</p>

Weeds can reduce upland rice yields in coastal sandy area. Density and growth of weeds can be controlled and reduced by an intercropping system between upland rice with soybeans. The study aimed to determine the weeds composition change and weeds biomass in various crop proportions of upland rice and soybean under intercropping. The research was conducted from December 2016 until March 2017, at coastal sandy soil of Samas, Bantul, Yogyakarta (8°00’03.5”S and 110°15’20.1”E). This study used a complete randomized block design (RCBD) with one factor and three replications. The treatments were crop proportions of upland rice and soybean under intercropping with 6 levels, such as 100:0 (upland rice monoculture), 80:20, 60:40, 40:60, 20:80, and 0: 100 (soybean monoculture). The results showed that there was weeds composition changes due to setting crop proportions of upland rice and soybean under intercropping at coastal sandy soil. Weed of sedges, grass, and broadleaf were found throughout the experimental plots, but varied in number and type of weeds among experimental plots. Weeds condition differed among the soybean proportion treatments &lt; 40% and  ≥ 40%. The average community coefficient value was &lt;75% which was dominated by Digitaria nuda and Eragrostis tenella under soybean proportion treatments &lt; 40%, and Ludwigia parviflora and Amaranthus lividus under soybean proportion treatments ≥ 40%. The linear model was established between the increase of soybean proportion to a decrease in dry weight of weeds as Y = -0.6624X + 67.699; R2 = 0.7224).<br /><br />Keywords: crops proportion, intercropping, weeds community<br /><br />

The correlation of major growth parameters with the yield of cassava in different growth phases was investigated in 2013 and 2014. This experiment was conducted to assess the effect of two cassava varieties and the different growth phases to the yield and yield components. In experiment, the varieties as treatment were arranged in a randomized complete block design (RCBD) with three replications. Two varieties consisted of superior Adira-4 and local varieties Singgah were used. The growth parameters (plant height, stem diameter, leaf number) and yield components (number of tuber, weight per tuber and tuber yield) in early growth phase, maximum vegetative growth phase and charging tuber phase, were observed. Based on the correlation results, the growth parameters and the yield highly affected to the final outcome of cassava tubers at different growth phases. In the early growth phase, occurs high demand to assimilate with the expense of storage root. However, from the maximum vegetative phase, growth parameters began to show a significant positive contribution to the tuber weight. Weight of fresh tuber in both varieties increased at the charging of tubers phase and thereafter (enlarged bulb). The early growth phase and maximum vegetative phase might not generate a significant contribution to the final yield of cassava tuber. Making those two periods were not suitable time for optimum harvesting result, and it still depended on the variety and its allocation.

Vegetables and flowers are produced under andisol and alfisol soils with elevations ranging from 350-1500 m above sea level (asl). Potatoe in Indonesia is a plant that has promosing economic value, so farmers are competing to plant the crop. Mountainous lands that were utilized into agricultural land needs to evaluate based on type of land use in order to know the potential of production and the impact of land damage that arises. This research had been conducted in Giritirta, Pejawaran, Banjarnegara, Central Java implemented on July 2017-November 2017. The method used was survei research on land quality with direct field observation, and collecting data from relevant agencies, and survei on farmer response was conducted by interview. Primary data taken was data obtained directly from the object of research through observation, interview with questionnaire, secondary data compiled were data obtained by previous researchers. The results showed that usage for agricultural in the location of the research in the form of cultivation annual crops the usable land with potatoe (Solanum tuberosum L.) as main crop and the technique of planting by aranging the slope with minimum land conservation measures. The level of erosion hazard is classified in very heavy class on all of Land Unit which causes the potential for high land degradation in a short time. The way mitigation to avoiding the damage by implementation on planting coffee arabica and tea in steep land (26%-40%) and quinine in very steep land (>40%). Land improvements made by making and repairing terraces land, strip grass and making rorak. INTISARITanaman sayur-sayuran dan bunga-bungaan banyak dihasilkan di tanah andisol dan alfisol dengan elevasi berkisar antara 350-1500 m di atas permukaan laut (dpl). Kentang di Indonesia merupakan tanaman yang memiliki nilai ekonomis cukup menjanjikan, sehingga petani berlomba-lomba untuk menanam tanaman tersebut. Lahan pegunungan yang sudah dimanfaatkan menjadi lahan pertanian perlu dilakukan evaluasi tipe pemanfaatan lahan guna mengetahui potensi produksi dan dampak kerusakan lahan yang timbul. Penelitian ini dilakukan di desa Giritirta, kecamatan Pejawaran, kabupaten Banjarnegara, Jawa Tengah yang dilaksanakan pada bulan Juli 2017-November 2017. Metode yang digunakan adalah penelitian survei terhadap kualitas lahan dengan pengamatan langsung di lapangan, dan mengumpulkan data-

Profitable crop production starts with a weed control program that includes preemergence herbicides to deliver long-lasting leaked, i.e. 7,95%, 7,32% and 7,03% respectively

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