Articles

Effect of Accession and Drought Stress on Growth and Adaptability of Pineapple (Ananas comosus (L.) Merr.) in Lowland Areas

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This research was conducted in the Greenhouse of the Agricultural Zone, Medan Baru, Kandang Limun, Muara Bangka Hulu Subdistrict, Bengkulu City. The study aimed to analyze the effect of different pineapple accessions (Ananas comosus (L.) Merr.) on the growth and adaptability of local pineapple under drought stress conditions. The experiment was arranged in a Completely Randomized Design (CRD) with two factors. The first factor was four pineapple accessions, and the second factor was the drought period, consisting of 15 and 30-day dry period. The results showed that the interaction between pineapple accessions and dry periods had a significant effect on shoot dry weight and stomatal density. Pineapple accession treatments had a significant effect on plant height, shoot fresh weight, and shoot dry weight. Dry period treatments significantly affected plant height and shoot dry weight. The results of the stress tolerance index (STI) at the 30-day dry period assessed during the vegetative stage indicated that pineapple accessions 19, 23, 24, and 25 all exhibited a similar level of drought tolerance and were classified  as medium tolerant to drought stress.

The Effect of Shade and NPK Fertilization on Growth and Yield of Asystasia gangetica as a Forage

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Asystasia gangetica is a weed usually found in oil palm plantations, which is used as a source of forage and cultivated at a known effective shade level and optimal fertilizer dosage. Therefore, this study was carried out at a place without shade (NS) and 75% of shading net (S) at the Experimental Field of the Faculty of Agriculture, Universitas Mulawarman, Samarinda, Indonesia. The seedlings used were planted and fertilized with NPK at doses of 0 g, 1.6 g, and 3.2 g per polybag. The results showed that the level of shade affected plant height, several branches, yield of dry matter shoot, the content of chlorophyll a, b, and a/b content, CP, CF, EE, NFE, and ash, but not on chlorophyll a+b. The dosage of NPK fertilizer affected plant height, the number of branches, yield of dry matter, chlorophyll a, b, and a+b content, CP, CF, EE, NFE, and ash content, while chlorophyll a/b ratio was not influenced. The interaction between shade level and NPK fertilizer dose only occurred in the number of branches, chlorophyll a, b, and b+c content, CP, CF, EE, and ash content, but not on chlorophyll a/b ratio and NFE content. The flowering rate was faster in NS plants, where those with NPK fertilizer dose of 0.32 g/polybag gave the highest yield, except for CP and ash content which had the highest yields on S plants with 0.32 g NPK/polybag.

The Influence of Integrated Fertilizer on Physiological and Agronomic Character of Aloe Vera L. Plant in Sandy Soil

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Abiotic environment usually influence the physiological properties of plants, which consequently affect its growth and yield. The research aims to determine the effect of combined integrated fertilizers on the physiological and agronomic character of Aloe vera plants. The experiment was laid out in RCBD, with three replications. Treatments were factorial combinations of cow manure rate (30 and 45 t ha-1) and humic nitrogen of eight levels i.e. urea, AS, NPK fertilizer, KNO3, humic urea, humic AS, humic NPK, and humic KNO3. Observed variables include physiological and agronomic component of plants. Data were subjected to ANOVA followed by DMRT at 5% significance level. There were significant interaction effect between manure rates and nitrogen sources upon all variables measured. Highest values of stomata index and density were achieved by the combined effect of manure rate of 30 t ha-1 with urea, while manure rate of 45 t ha-1 with humic urea resulted the highest value of stomata aperture. Increase in all physiological as well as agronomical characters were achieved by manure of 30 and 45 t ha-1 with the addition of humic urea.