Hikaru Akamine

Effects of Application of N, P and K Alone or in Combination on Growth, Yield and Curcumin Content of Turmeric (Curcuma longa L.)

Crops respond differently to different fertilizer elements, and proper fertilizer management for a plant species is important for increasing yield and quality. Nitrogen (N), phosphorus (P) and potassium (K) are the three major nutrients, which individually and/or together maintain growth, yield and quality of plants (Mazid, 1993; Ivonyi et al., 1997). N is involved in chlorophyll formation, and it influences stomatal conductance and photosynthetic efficiency (Mazid, 1993; Ivonyi et al., 1997). N is responsible for 26-41% of crop yields (Mazid, 1993; Maier et al., 1994, 1996). K plays catalytic roles in the plant rather than becoming an integral part of plant components. It regulates the permeability of cell walls and activities of various mineral elements as well as neutralizing physiologically important organic acids. Plants with an inadequate supply of K show poor fruit or seed formation, yellowing of the leaves, poor growth, and low resistance to coldness and drought (Oya, 1972). A sufficient supply of K promotes N uptake efficiency of plants due to its stimulant effect on plant growth. P indirectly promotes plant growth and absorption of K as well as other nutrients (Oya, 1972). Turmeric (Curcuma longa L.) is used in many countries as a spice and cosmetic (Ishimine et al., 2003; Hossain et al., 2005a, b). It is now a popular medicinal plant worldwide. Curcumin the main component of turmeric functions as a medicine with anti-inflammatory, anti-mutagenic, anti-carcinogenic, anti-tumor, anti-bacterial, anti-oxidant, anti-fungal, anti-parasitic and detox properties (Hermann and Martin, 1991; Osawa et al., 1995; Sugiyama et al., 1996; Nakamura et al., 1998). The efficacy of C. longa found on a specific disease varies with the studies, and in some cases no efficacy was found (Hermann and Martin, 1991; Osawa et al., 1995; Sugiyama et al., 1996; Nakamura et al., 1998). Such differences may be due to variation in the curcumin content which is assumed to depend on the fertilizer elements. Turmeric is a horticultural crop demanding heavy fertilization for increasing yield and quality (Reddy and Rao, 1978; Govind et al., 1990; Yamgar et al., 2001). We reviewed several papers and found that the chemical fertilizers affect growth, yield and quality of turmeric variously, and the effects of N, P and K alone or in combination are not clear, because farmyard manure was used together and some experiments did not include control treatment (Reddy and Rao, 1978; Govind et al., 1990; Yamgar et al., 2001; Behura, 2001). Turmeric is commercially cultivated in Okinawa, but yield per unit area and curcumin content are very poor, because fertilizer management is not well known to the farmers (Hossain and Ishimine, 2005). In previous studies, we evaluated planting depth, time, pattern, seed size and soil types on growth and yield of turmeric in Okinawa (Ishimine et al., 2003, 2004; Hossain et al., 2005a, b; Hossain and Isimine, 2005). The present study was undertaken to evaluate the effects of N, P and K alone or in combination on growth, yield and curcumin content of turmeric.

Effects of Planting Pattern and Planting Distance on Growth and Yield of Turmeric (Curcuma longa L.)

Abstract The effects of planting pattern and planting distance on the growth and yield of turmeric (Curcuma longa L.) were examined in Okinawa Prefecture situated in southern Japan. The dry weights of shoot and rhizome (yield) of turmeric planted in a triangular pattern were heavier than those planted in a quadrate pattern. A 30-cm-triangular planting resulted in the heaviest shoot and rhizome yield among the planting patterns examined. Dry weight of shoot per unit land area (m2) was significantly heavier when planted at a 20- and 30-cm spacing than when planted with a larger spacing, whereas the highest yield was obtained when planted at a 30-cm spacing followed by 20- and 40-cm spacing. When turmeric was planted at a 20-cm spacing, rhizome could not expand properly, which ultimately resulted in the smaller rhizome compared with that planted with a larger spacing. The highest turmeric yield coupled with the lowest weed biomass was obtained on the two-row ridge in a 75-100 cm width compared with a one- or two-row ridge in a larger or smaller width. This study indicates that for reducing weed interference and obtaining higher yield, turmeric should be planted in a 30-cm-triangular pattern on two-row ridge in a 75-100 cm width.

Effects of Seed Rhizome Size on Growth and Yield of Turmeric (Curcuma longa L.)

Abstract Turmeric (Curcuma longa L ) plant species produces different sizes of daughter rhizomes (R) and mother rhizomes (MR), which are the only propagules (seed) for its cultivation. Here, we evaluated the effects of seed rhizome size on growth and yield of turmeric. Daughter rhizomes of 5-50 g (R-5 g~R-50 g) and mother rhizomes of 48-52 g (MR) were tested. The heavier the R up to 40 g, the better the plant growth, and the plants from the R-30 g, R-40 g, R-50 g and MR grew similarly well. The seed rhizomes with a greater diameter developed vigorous seedlings. The plants grown from R-30 g, R-40 g and R-50 g had a similar plant height, tiller number and leaf number, which were significantly higher than those from lighter R. The plants from R-30 g, R-40 g and R-50 g had a significantly larger shoot biomass and higher yield than those from smaller R in both the greenhouse and field experiments. R-50 g was easily broken at the time of planting, and had secondary and tertiary daughter rhizomes, which developed thinner plants and resulted in a lower yield. The shoot biomass and yield were highest in the plants grown directly from MR, and lower in the plants grown from daughter rhizomes attached to MR. This study indicates that the turmeric seed rhizome should be 30-40 g with a larger diameter, and seed mother rhizome should be free from daughter rhizomes.

Effect of Nitrogen Fertilization on Photosynthetic Characters and Dry Matter Production in F1 Hybrids of Rice (Oryza sativa L.)

Abstract This study was carried out to determine heterosis in different photosynthetic and morphological characters, and to observe photosynthetic ability and dry matter production potentiality of two F1 hybrids of rice grown in pots supplied with N fertilizer in the normal or double dose. Photosynthetic rate in terms of CO2 exchange rate (CER), leaf N concentration, SPAD value, soluble protein content and ribulose-l,5-bisphosphate carboxylase (Rubisco) activity was increased significantly by doubling the dose of fertilizer in most parental cultivars and F1 hybrids, but the rate of increase was higher in F1 hybrids than in their parents. Several morphological parameters were also increased significantly by doubling the dose of fertilizer, but not the percentage of dead leaf blades. The rates of increase of plant height, leaf area and dry matter production were higher in F1 hybrids. In particular, the rates of increase of total dry matter and root weight were very high in one of the F1 hybrids. The percentage of dead leaf blades decreased significantly in plants grown with a high dose of fertilizer as a result of higher leaf N concentration. At a normal fertilizer dose, both F1 hybrids failed to show positive heterosis in most photosynthetic characters. However, positive heterosis was found at a high fertilizer dose. Both F1 hybrids showed positive heterosis over mid-parent in dry matter production per plant at both fertilizer doses. One of the F1 hybrids also showed positive heterosis over the better parent. Heterosis in most photosynthetic and morphological characters was increased by increasing the dose of fertilizer. The sufficient supply by doubling the dose of fertilizer increased the leaf N concentration, chlorophyll content, soluble protein content and Rubisco activity in F1 hybrids, which led to higher positive heterosis in CER. A larger leaf area plus higher CER, especially at a high fertilizer dose, contributed to higher dry matter production in F1 hybrids of rice.

Influence of nitrogen fertilization on tropical‐grass silage assessed by ensiling process monitoring using chemical and microbial community analyses

Aims:  Utilization of silage in livestock farming is expected to increase in developing countries in the tropical and subtropical parts of the world. The aim of this study was to investigate the influence of nitrogen fertilization on the chemical composition of herbage, ensiling process and silage quality, and to contribute to the improvement of tropical‐grass silage preparation.

Effects of Relative Light Intensity on the Growth, Yield and Curcumin Content of Turmeric (Curcuma longa L.) in Okinawa, Japan

Abstract The effects of relative light intensity (RLI) on the growth, yield and curcumin content of turmeric (Curcuma longa L.) were examined in Okinawa, Japan. The plants were shaded with white nets with different mesh sizes for maintaining respective RLI. Five RLI, 100 (without shading), 82, 79, 73 and 59% in 2004−2005 and four RLI, 100, 68, 52 and 48% in 2005−2006 were evaluated. In the first experiment, plant height increased markedly, but the number of leaves and tillers, and SPAD value increased slightly in the plants grown at 59−82% RLI compared with control (without shading). Turmeric shoot biomass and yield increased significantly at 59−82% RLI and they were highest at 73% RLI in the first experiment. Curcumin content of turmeric increased markedly at 59−73% RLI as compared with the control in the first experiment. Similar results in plant growth, shoot biomass, yield and curcumin content were obtained in the second experiment, but the effects of RLIs were smaller than in the first experiment because of late planting. This study indicates that turmeric is a partial shade-tolerant plant that could be cultivated at around 59−73% RLI for higher yield and curcumin content in Okinawa. However, the degree of RLI required for better turmeric cultivation may vary with the place, year and irradiance level.

Effects of soil types and fertilizers on growth, yield, and quality of edible Amaranthus tricolor lines in Okinawa, Japan

Abstract Soil types and fertilizer regimes were evaluated on growth, yield, and quality of Amaranthus tricolor lines, IB (India Bengal), TW (Taiwan), BB (Bangladesh B), and BC (Bangladesh C) in developing management practices in Okinawa. Growth and yield of all amaranth lines were higher in gray soil (pH 8.4) than in dark red soil (pH 6.6) and red soil (pH 5.4). The combined NPK fertilizer resulted in highest growth parameters and yield of amaranths in all soils. Nitrogen fertilizer alone did not affect growth parameters and yield of amaranths in dark red and red soils. Growth parameters and yield increased similarly with the 30, 40, and 50 g m−2 of NPK fertilizer in BB line, and with the 20, 30, 40, and 50 g m−2 in BC line. Agronomic efficiency of NPK fertilizer at 50 g m−2 was not prominent on the amaranths, compared to the fertilizer at 40 g m−2. Amaranth lines had higher Na in dark red and red soils, while K and Mg in gray soil, Ca in gray and red soils, and Fe in dark red soil. The NPK fertilizer resulted in higher Na, Ca, Mg, and P in BB line in glasshouse. These minerals in BB line were not clearly affected, but in BC line were lower with NPK fertilizer at 20–50 g m−2 in field. These studies indicate that gray soil is best for amaranth cultivation and combined NPK fertilizer at 20–40 g m−2 is effective in gray soil in Okinawa for higher yield and minerals of amaranth.

Weed Infestation in Turmeric in Okinawa, Japan

A field experiment was conducted in Okinawa, Japan from 2005 to 2007 to evaluate the effect of purple nutsedge and other weeds on turmeric growth and yield and determine the effective weed-control period to minimize crop interference. Treatments consisted of all weeds removed at 70, 115, and 160 d sequentially after planting (DAP), all weeds except purple nutsedge removed at these three dates, plus weedy and weed-free controls. Purple nutsedge density increased until 115 DAP when grown alone with turmeric and thereafter decreased markedly, whereas it increased only until 70 DAP when grown with other weeds. Weed reinfestation in turmeric that was sequentially weeded was high until 115 DAP, but thereafter was negligible. In the weedy control, the weed infestation was severe until 160 DAP. Plant height and leaf and tiller number per plant of turmeric increased rapidly from 70 to 160 DAP. Season-long weed infestation significantly reduced shoot biomass and rhizome yield of turmeric, but both were similarly high among treatments of weed-free turmeric, all weed removal, and removal of all weeds except purple nutsedge. Purple nutsedge (> 3,000 plants/m2) did not significantly reduce turmeric yield, whereas the combined weed species reduced yield by greater than 40%. Thus, crop interference by purple nutsedge was not high, and other weeds could be removed during 70 to 160 DAP for reduced labor requirements and higher yield of turmeric. Nomenclature: Purple nutsedge, Cyperus rotundus L. CYPRO, turmeric, Curcuma longa L