AEJSA Volume 13, Number 4: October-December, 2019


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Phosphate mineralization by a rice (Oryza sativa L.) rhizoplanic Enterobacter sp.

Nilima Dash, Tushar Kanti Dangar

ABSTRACT: Rhizoplane is the hotspot of plant microbe interaction where various plant growth promoting bacteria convert insoluble phosphatic compounds into accessible form for plants; thereby enhance plant health and productivity. An efficient rhizoplanic plant growth promoting Enterobacter sp. R1 of rice (O. sativa L.) cv. Swarna Sub-I was thoroughly studied which mineralized Ca-phosphate (574.7 μg/ml), Zn phosphate, rock phosphates and slag and also tolerated 9% NaCl. Besides P-solubilization (PS), it produced indole, siderophore (66.35 mg/g dr. wt.) and ammonia which would promote growth of plants. The bacterium mineralized P by acid (22.25 U/ml) and alkaline phosphatase (76.37 U/ml) and organic acid (citric acid, lactic acid, tartaric acid etc.) production. R1 challenged plants had enhanced root (66.67%) and shoot (28.81%) length in the laboratory test, and augmented growth and production in pot and field conditions. The bacterium intrinsically possessed the P solubilizing pqqC gene. Multiple plant growth promoting (PGP) traits and salt tolerance rendered the organism to be potent for biofertilizer production suitable for both non-saline and saline environments.

[ FULL TEXT PDF 1-17 ] DOI: 10.22587/aejsa.2019.13.4.1

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Effect of Nitrogen Addition to Organic + Inorganic Liquid Fertilizers and Seasons on Productivity of Tea Shoots

Zakarias F.M. Hukom, Didik Indradewa, Benito H. Purwanto, & Eka T.S. Putra

ABSTRACT: The tea plant (Camellia sinensis (L.) O. Kuntze) is the most popular beverage plant in the world because of its high bioactive compounds and antioxidant properties contained in its shoots. The productivity of tea shoots highly depends certain factors, including fertilization. In a commercial tea plantation, the application of N fertilizer plays essential roles in determining the productivity of tea shoots. It is commonly implemented by mixing N with organic + inorganic liquid fertilizer. However, the response of tea plant to N fertilizer varies depending on its requirement and climate condition. This study investigated the effect of Nitrogen addition in organic + inorganic liquid fertilizer on the productivity of tea shoots in different seasonal periods. The observation parameters consisted of five indicators, namely shoot number, shoot length, shoot elongation rate, shoot fresh weight, and shoot dry weight. Randomized complete block design using overseason was set up with three blocks. Each block was occupied by five different treatments, namely control, no addition N, addition 2.33 g N, addition 7.00 g N, and 11.67 g N. Data analysis was conducted using ANOVA (5%) and followed with HSD Tukey (5%). Results demonstrated that there was a significant difference in the productivity of tea shoots in every treatment. The application of 3000 ppm organic + inorganic liquid fertilizer without Nitrogen addition performed the best outcome than others. This treatment significantly increased the productivity of fresh weight shoots around 56.34% (24.14-ton ha -1 year -1) higher than the control treatment (10.54 ton ha -1 year -1). Interestingly, it also highly improved the production of dry weight shoots by around 61.51% (4.8 ton ha -1 year -1) greater than the control treatment (1.84 ton ha -1 year -1). Thus, it was recommended to replace the conventional fertilization that was commonly implemented in the tea plantation with low productivity.

[ FULL TEXT PDF 18-26 ] DOI: 10.22587/aejsa.2019.13.4.2

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