858 research outputs found

    Influence of Selected Cover Crops and Biochar on the Yield Advantage of Two Taro (Colocasia esculenta) Cultivars in Samoa

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    On farm trials were conducted to compare dry matter yields and nutrient uptake of selected tropical cover crops and biochar application on different Samoan inceptisols. Consequent improvements in corm yield of two cultivars Samoa 1 and Samoa 2 were determined. Plant analyses showed that the N and P contents of erythrina was grossly higher than mucuna cover. Yet, Mucuna pruriens resulted in the highest nutrient buildup over the six month fallow period. Yield data suggests that mucuna with low rates of complete fertilisers can help maintain optimum taro yields under the shortened fallow durations. However, it appears that the yield responses of the taro crop to fallow treatments are site-specific

    Nutrient Use Efficiencies of Taro Cultivars Genetically Improved for Leaf Blight Resistance

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    Two blight resistant taro cultivars, taro uli and taro mumu were planted and harvested for biomass measurements on a monthly basis for a total of eight months through destructive sampling. It is worthy to note that taro uli plants absorbed 17% less N, 26% less P and 20% less K than those of taro mumu. Although taro mumu resulted in higher total plant (21.4%) and corm dry matter (10.4%) productions, cultivar taro uli had a higher nutrient use efficiency over taro mumu. Results show that taro mumu had a higher nutrient use efficiency over cultivar taro uli. Based on nutrient use efficiency of the cultivars, taro uli is recommended for marginal to rich soils while taro mumu for rich soils

    Joint Scheduling of URLLC and eMBB Traffic in 5G Wireless Networks

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    Emerging 5G systems will need to efficiently support both enhanced mobile broadband traffic (eMBB) and ultra-low-latency communications (URLLC) traffic. In these systems, time is divided into slots which are further sub-divided into minislots. From a scheduling perspective, eMBB resource allocations occur at slot boundaries, whereas to reduce latency URLLC traffic is pre-emptively overlapped at the minislot timescale, resulting in selective superposition/puncturing of eMBB allocations. This approach enables minimal URLLC latency at a potential rate loss to eMBB traffic. We study joint eMBB and URLLC schedulers for such systems, with the dual objectives of maximizing utility for eMBB traffic while immediately satisfying URLLC demands. For a linear rate loss model (loss to eMBB is linear in the amount of URLLC superposition/puncturing), we derive an optimal joint scheduler. Somewhat counter-intuitively, our results show that our dual objectives can be met by an iterative gradient scheduler for eMBB traffic that anticipates the expected loss from URLLC traffic, along with an URLLC demand scheduler that is oblivious to eMBB channel states, utility functions and allocation decisions of the eMBB scheduler. Next we consider a more general class of (convex/threshold) loss models and study optimal online joint eMBB/URLLC schedulers within the broad class of channel state dependent but minislot-homogeneous policies. A key observation is that unlike the linear rate loss model, for the convex and threshold rate loss models, optimal eMBB and URLLC scheduling decisions do not de-couple and joint optimization is necessary to satisfy the dual objectives. We validate the characteristics and benefits of our schedulers via simulation

    A comparative study on strength improvementand CBR properties of NIT hostel area soil by using calcium carbide residue and fly ash.

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    The main objective of this experimental study is to improve the properties of the soil by adding the waste material which can cause environmental pollution. Calcium Carbide Residue and Fly Ash mixture which are waste product of acetylene gas factories and steel plant respectively has been selected to add in the soil sample in different ratios. The soil properties with and without adding of waste materials (Calcium Carbide residue and Fly Ash ) have been studied. An attempt has been made to use these waste material for improving the strength and CBR values of soil which will also prove environment friendly. Thus , from this experimental study will help in reduction of pollution and improvement of soil strength

    Dry matter accumulation, nutrient uptake and nutrient use efficiency of two improved cultivars of taro (Colocasia esculenta) under screen house conditions in Samoa

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    Taro (Colocasia esculenta (L.) Schott) is a staple crop of many of the South Pacific nations with an ever increasing export demand. In recent years, yields of taro have in creased dramatically through breeding and selection. However, selections of improved lines are often entirely based on final yield. There are many physiological pathways by which increased potential yield may be achieved. Factors such as the accumulation of dry matter and nutrient use efficiency, merit investigation. Two improved (blight resistant) taro cultivars were planted and harvested for biomass measurements on a monthly basis for a total of eight months (30-240 days after planting) through destructive sampling. At each harvest, plants were separated into various plant parts and their dry matter accumulation and nutrient content were determined. Comparatively, cultivar Samoa 2 showed significantly higher uptake of N (25%), P (37.5%), K (33%), Mg (36.4%), Mn (22.7%) and Zn (48.3%) than cultivar Samoa 1. Even though maximum levels of total plant uptake of nutrients by the two cultivars did not differ between the cultivars, cultivar Samoa 1 plants absorbed 17% less N,26% less P and 20% less K than those of cultivar Samoa 2 with the uptake uniformly distributed over the entire life cycle of the crop. Although cultivar Samoa 2 resulted in higher total plant (19.6%) and corm dry matter (10.4%) productions, cultivar Samoa 1 had a higher nutrient use efficiency, (kg of edible dry matter produced per kg of nutrient taken up), for N, P, K, Mg, Mn and Cu over cultivar Samoa 2. However, for Ca, Fe and Zn. Cultivar Samoa 2 had a higher nutrient use efficiency over cultivar Samoa 1. Based on nutrient use efficiency of the cultivars, Samoa 1 is recommended for marginal to rich soils while Samoa 2 for good to rich soils
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