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991.
Katsuyuki Katayama Osamu Ito Joseph Jackson Adu-Gyamfi Theertham Pradymna Rao Esperanza V. Dacanay Tadakatsu Yoneyama 《Soil Science and Plant Nutrition》2013,59(1):143-150
A long-term experiment was carried out on a Vertisol from 1986 to 1992 to examine the combined effects of NPK fertilizers on yield using sorghum (Sorghum bicolor L. Moench cv. CSH 5) and short-duration pigeonpea (Cajanus cajan L. Millsp. cv. ICPL 87). The fertilizer treatments were as follows: 0 (no fertilization), N (150 kg N ha-1 ), P (65.5 kg P2O5 ha-1), K (124.5 kg K2O ha-1), and all possible combinations (NP, NK, PK, and NPK). In this study we continued this experiment during the period 1993 to 1994 and analyzed the crop yield response to fertilizers and the N balance. The amount of N derived from the atmosphere and fertilizer was estimated by the 15N natural abundance method and l5N isotope dilution method, respectively. A combined application of Nand P fertilizers gave the highest grain yield for the two crops under the 8th and 9th continuous croppings, unlike the application of K fertilizer. The values of total N for the two crops were significantly higher in the NP and NPK plots. These crops took up N mainly from soil. There was a significant positive relationship between the uptake of Ndff and Ndfs by each crop. Pigeonpea or sorghum took up more N from the soil in the N fertilizer plots than in the plots without N, suggesting that soil N fertility was enhanced and the amount of N supplied from soil increased in the plots with consecutive application of N fertilizer for 7 y. Even pigeonpea, which fixes atmospheric N inherently, needed N fertilizer to achieve high grain yield, suggesting that N fixation by the nodules was not always sufficient to meet the N requirements of the crop under these conditions. Although fertilizer N exerted a beneficial effect on plant growth and yield in the two crops, the values of fertilizer N recovery (FNR) by the two crops were considerably low. Therefore, it is suggested that the development of N fertilizer management which could maximize FNR of each crop should be promoted. 相似文献
992.
B. Bapuji Rao U. Triveni N. Harisatyanarayana P. Latha N. Venugopala Rao V.U.M. Rao 《Archives of Agronomy and Soil Science》2013,59(7):989-999
Mesta (Hibiscus sabdariffa) is an important fibre crop in the north coastal zone of Andhra Pradesh which accounts for 59% of India's total production of mesta. The area under this crop has reduced dramatically in recent years and in order to understand the contribution of weather to this decline, long-term experimental data (14 years) on mesta cv. AMV-4 and regional crop yields were analysed. Crop yields decreased in seasons when rainfall exceeded 900 mm and maximum temperature remained below 32.0°C during 10–16 weeks after sowing (WAS), which coincided with the active vegetative stage. The average yields of the region were high when seasonal rainfall ranged between 600 and 725 mm. Increased fibre yields were observed when increasing seasonal rainfall coincided with maximum temperatures exceeding 33.5°C. Fibre yields from a long-term experiment showed strong positive correlations with maximum temperature during 6–16 WAS (r = 0.79) and with mean diurnal temperature range (8.6–10.7°C) during 11–19 WAS (r = 0.66). Step-wise regression showed that maximum variability in fibre yield was explained by maximum temperature which could be used to develop models to predict yield at least one month in advance with acceptable accuracy. This prediction could then be used as an input for crop planning and market intelligence. 相似文献
993.
为明确广东省油茶品种(系)对炭疽病的抗性及引起油茶炭疽病的病原菌种类,对广东省肇庆市、广州市和韶关市的149个油茶品种(系)进行田间抗性调查,从发病组织中分离纯化致病菌,观察菌株形态学特征,并结合3-磷酸甘油醛脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)基因扩增序列进行分子生物学鉴定。结果显示,有93.29%的油茶品种(系)发生炭疽病,3个调查地油茶炭疽病的平均发病率为18.86%~24.25%,较抗病的油茶品种(系)占调查总数的53.02%,感病油茶品种(系)占调查总数的46.98%。其中,海南3号、长林400号和湘林89号等10个品种(系)表现为近免疫,揭阳5号、桂14号和湘林350号等16个品种(系)表现为高抗,赣5190号、湘林27号和岑软11号等53个品种(系)表现为中抗,赣兴46号、赣州S4号和赣州R10号等36个品种(系)表现为中感,岑软11-3000号、长林53号和湘林67号等34个品种(系)表现为高感,其中岑软11-19号发病率高达65.00%。共分离获得油茶炭疽病致病菌25株,结合形态学特征和基于GAPDH序列的系统发育树分析,将其中24株鉴定为果生炭疽菌Colletotrichum fructicola,1株鉴定为为暹罗炭疽菌C. siamense。筛选的油茶抗病品种(系)可作为广东省油茶良种选育材料,且该省油茶炭疽病主要由果生炭疽菌引起。 相似文献
994.
The novel pyrene based dye sensor was designed and synthesized through the reaction between pyrene-1-carboxaldehyde and 4-phenylthiosemicarbazide. This dye sensor showed selectivity and sensitivity binding properties toward F? ion with showing absorption and emission changes in DMSO. These optical properties were investigated by using UV-vis spectrometer and emission spectrophotometer. In addition, electron distributions and HOMO/LUMO values of this dye sensor were simulated and calculated with theoretical calculations of Material Studio 4.3. 相似文献
995.
M. B. Nageswara Rao G. Satyanarayana A. Shiv Raj N. Gnana Kumari V. Padmanabham 《The Journal of Horticultural Science and Biotechnology》2013,88(3):517-519
SummaryIBA-treated cuttings rooted only when prepared fom bark-ringed shoots. The response to ringing declined with increasing age of the tree. However, on marcotting, the ringed shoots of four year old trees showed more and earlier rooting. 相似文献
996.
K. N. Vishnu Prasanna D. V. Sudhakar Rao 《The Journal of Horticultural Science and Biotechnology》2013,88(5):546-550
SummaryThe effect of storage temperature on ripening, shelf life and chemical composition of custard apple (Annona squamosa L.) fruits stored at 10,15,20 and 25°C was studied. The safe range of storage temperature was found to be between 15 and 20°C, with maximum shelf life at 15°C. The ripening of fruits was observed on days 4, 6 and 9 of storage at 25,20, and 15°C respectively. The colour of the pulp, texture, taste and flavour of ripe fruits held at 25 and 20°C were superior followed by fruits stored at 15°C. At 10°C, the fruits became hard with surface blackening, messy pulp and less sweetness. The major changes during ripening were a continuous decrease in fruit firmness and starch content and a continuous increase in TSS and sugars, the changes being more rapid at 25 and 20°C than at 15 and 10°C. The acidity and ascorbic acid contents increased slightly during the initial stages of ripening followed by a decline, in the fruits stored at different temperatures. Custard apple fruits stored at 25 and 20CC had a clear climacteric peak whereas those stored at 15 and 10°C did not show any distinct rise in respiration rate. Ethylene peak (2.40 µl kg–1 h–1) coincided with the respiratory climacteric at 25CC storage, corresponding with the peaks in TSS, sugars, ascorbic acid and acidity. 相似文献
997.
Currently, the biomass of an invasive and obnoxious weed, kunai grass (Imperata cylindrica), is uncontrollably burnt in Papua New Guinea in subsistence farming systems resulting in unwarranted negative environmental consequences. We explored the possibility of sustainable utilization of biochar produced from the weed biomass along with a standard feedstock‐rice husk (Oryza sativa). Biochars were produced with lab‐scale pyrolysis at 550°C, characterized for chemical properties and plant nutrient composition. Further, agronomic efficacy of soil incorporation of biochars (5 t ha?1) or co‐applied with mineral fertilizers (100, 11, and 62 kg ha?1 N, P, K, respectively) was tested for sweet potato (Ipomoea batatas L. Lam) in a field experiment. The two biochars differed significantly (P < 5%) with respect to recovery from the feedstocks, chemical characters and nutrient composition. Kunai grass biochar was poorer in nutrients (< 1%) with distinctly alkaline pH and higher electrical conductivity. Biochar amendment to soil showed significant (P < 5%) improvement of soil moisture, while co‐application of biochars along with mineral fertilizers showed soil moisture decrease. Biochar amendment improved the growth parameters and total tuber yield of sweet potato by about 20%, while co‐application with mineral fertilizers augmented total tuber yield by 100% and above‐ground biomass yields by > 75%. Besides, improving agronomic performance of sweet potato crop, co‐application of biochars with mineral fertilizers enhanced uptake of N, P, K, Ca, Mg, and S. Production and utilization of biochar in sweet‐potato production could offer an efficient means of disposing biomass of kunai grass with concomitant productivity improvement in Papua New Guinea. 相似文献
998.
999.
X-ray diffraction patterns of transfer RNA consistent with the presence of short parallel helices in the molecule 总被引:1,自引:0,他引:1
X-ray diffraction data of yeast formylmethionine transfer RNA, Escherichia coli phenylalanine transfer RNA, and Escherichia coli arginine transfer RNA single crystals are compared with the Fourier transform of a helix. The results are consistent with the presence of short parallel double helical segments in the transfer RNA molecules. 相似文献
1000.
PV Hobbs JS Reid RA Kotchenruther RJ Ferek R Weiss 《Science (New York, N.Y.)》1997,275(5307):1776-1778
Airborne measurements in smoke from biomass burning in Brazil have yielded optical parameters that permit an improved assessment of the effects of smoke on Earth's radiation balance. The global-mean direct radiative forcing due to smoke from biomass burning worldwide is estimated to be no more than about -0.3 watt per square meter (cooling), compared with +2.45 watts per square meter (warming) due to anthropogenic greenhouse gases. On regional scales, direct radiative forcing due to smoke can be large and might indirectly affect global climate. 相似文献