Tuber Density Research Articles

EFFECT OF ORGANIC FERTILIZER AND BORON FOLIAR ON QUANTITATIVE AND QUALTITATIVE TRAITS POTATO FOR PROCESSING

A field experiment was carried out at University of Baghdad, College of Agricultural Engineering Sciences during fall season of 2020 and spring season of 2021. This study was aimed evaluate the effect of the organic fertilizer and boron foliar on the yield of potatoes for processing. The factorial experiment (5*4) within RCBD and three replicates. The organic fertilizer as palm peat at four levels (0, 12, 24 and 36 ton. ha-1) in addition to the chemical fertilizer recommendation treatment. Boron at four Concentrations 0, 100, 150 and 200 mg. L-1 . The results revealed significant different among application of organic fertilizer at the level of 24 ton. ha-1 and the foliar application of boron at a concentration of 100 mg. L-1 in the leaves area (105.65 and 159.63 dm2 plant-1 for both seasons, respectively), the tubers number, yield and TSS reached 13.78 tubers. plant-1, 9.27 tubers. plant-1 and 833.3 g. plant-1 1122.2 g. plant-1 and 6.67, 5.43% respectively. While the highest tubers dry weight recorded the significant value at the application of 36 ton. ha-1 with foliar application of boron at 150 mg. L-1 reached 21.30 and 26.02% for both seasons, respectively. Also, starch and the specific density of tubers were increased (14.98 and 19.19%) and (1.085 and 1.108%) for both seasons, respectively.

Assessment of Potato (Solanum tuberosum L.) Performance for Yield and Quality Production under Natural Farming System in Gird Region of Madhya Pradesh, India

Objective of the Study: To assess the potato (Solanum tuberosum L.) performance for yield and quality production under natural farming system in gird region of Madhya Pradesh.
 Study Design: Randomized complete block design.
 Place and Duration of Study: ICAR-Central Potato Research Institute- RS, research farm Gwalior during winter (Rabi) season of 2022-2023.
 Methodology: Selected 5 plants from each treatment and replicated 3 times. Then follows methods as per given in materials and methods section of paper. Treatments T1: Control, T2: Inorganic practices (standard technology), T3: NADEP compost @ 25 t/ha + Azotobacter @ 1L/ha + PSB (Phosphorus solublizing bacteria) @ 1L/ha, T4: T3+ FYM @ 25 t/ha, T5: T3 + Vermicompost @ 7.5 t/ha, T6: T3+ neem cake @ 5 t/ha + foliar spray of copper oxychloride @ 3 g/L, T7: Integrated practice [90% RDF through inorganic sources {urea, SSP, MOP}, 10% RDF through organic sources i.e., FYM @ 25 t/ha.
 Results: Results revealed that maximum number of tubers (135.03, 144.598 and 245.344) for grade 25-50 g, 50-75 g and >75 g respectively, highest number of tubers per ha (591286 at harvest), maximum yield of tubers (6.75, 10.844 and 18.40 t/ha) for grade 25-50 g, 50-75 g and >75 g respectively, highest yield of tubers (37.665 t/ha), highest true density of tubers (1.123 g/cc), highest tuber dry matter (17.173%) and highest starch content (14.313%) were recorded in treatment T7. While, the maximum number of tubers (129.08) for grade (0-25 g) and, maximum yield of tubers (3.2098 t/ha) for grade (0-25 g) was found in control plot.
 Conclusion: Among 7 treatments, T7- Integrated practice (90% inorganic practices, 10% organic) found better for number of tubers in different grades, yield of tubers in different grades, total tuber yield (t/ha) and for quality parameters e.i., True density (g/cc), Tuber dry matter (%) and Tuber starch content (%).

EVALUATION OF EMERGENCE AND GROWTH RESPONSE OF CYPERUS ROTUNDUS AS INFLUENCED BY SOWING DEPTHS AND WATER REGIMES

Cyperus rotundus is rapidly growing plant can quickly form dense colonies through the extensive underground system of tuber and rhizomes. It is highly competitive for resources and causes a significant yield reduction in field crops. The nonchemical method has recently been practiced to control this noxious weed species. The current study was conducted to determine the effect of sowing depths (4, 8, 12, and 16 cm) and water regimes (deficit irrigation, medium irrigation, and frequent irrigation treatments) on C. rotundus shoot growth and underground growth of tubers in pots soil. Weed emergence, i.e., mean emergence time (MET), emergence index (EI), final emergence percentage (FEP), and shoot growth traits i.e. shoot density, shoot fresh weight, shoot dry weight, and tuber growth traits i.e. tuber density, tuber weight, root density, and root weight were recorded under the completely randomized (CRD) factorial design. The greatest suppression of C. rotundus emergence and growth was found at 16 cm sowing depth. The mean emergence time (MET) of C. rotundus was increased by increasing the sowing depth. Minimum value of shoot densty (9.5 g) and tuber density (15.75 g) were recorded at 16 cm sowing depth under deficit irrigation treatment respectively.While shoot and tuber desnity traits were also drastically suppressed by increasing sowing depth at the deficit irrigation level. It is concluded that sowing depths and deficit irrigation methods can be included as a reliable approach for controlling purple nutsedge shoot and tuber growth.

Lowland Ecotype Cyperus rotundus L. Affects Growth and Yield of Rice under Flooded Conditions in the Philippines

Lowland ecotype Cyperus rotundus L. has been reported to infest irrigated lowland ricefields in the Philippines. Its effects on the growth and yield of rice under flooded conditions are unknown. Two experimental runs were conducted in a screenhouse to determine the growth of lowland ecotype C. rotundus with transplanted and wet direct-seeded rice at sowing densities of 0, 22, 44, 66, and 88 initial germinating tubers m–2, as well as its effects on the growth and yield of rice. Except for height, growth variables of lowland ecotype C. rotundus were increased with the increase in its germinating tuber densities. Compared with 22 germinating tubers m–2, its number of off-shoots and tubers plus shoot and root biomass at 44–88 germinating tubers m–2 increased by up to three times. Growth variables of rice were reduced by the weed. Grain yield of transplanted rice was reduced by 14–38%, whereas that of wet direct-seeded rice was reduced by 11–28%. The estimated yield losses of transplanted rice per weed plant were 0.8 and 0.1% as germinating tuber density and number of off-shoots approached zero (i) and 75.7 and 66.1% as the variables approached infinity (a). Estimated yield losses of wet direct-seeded rice per weed plant were 0.6 and 0.1% as the two variables approached i and 63.8 and 100% as variables approached a. Results suggest that lowland ecotype C. rotundus can grow well and reduce the growth and yield of rice under flooded conditions. Although the findings were obtained under screenhouse conditions, the results imply the need of developing a holistic weed control strategy against the weed.

Development of an Optimal Algorithm for Detecting Damaged and Diseased Potato Tubers Moving along a Conveyor Belt Using Computer Vision Systems

The article discusses the problem of detecting sick or mechanically damaged potatoes using machine learning methods. We proposed an algorithm and developed a system for the rapid detection of damaged tubers. The system can be installed on a conveyor belt in a vegetable store, and it consists of a laptop computer and an action camera, synchronized with a flashlight system. The algorithm consists of two phases. The first phase uses the Viola-Jones algorithm, applied to the filtered action camera image, so it aims to detect separate potato tubers on the conveyor belt. The second phase is the application of a method that we choose based on video capturing conditions. To isolate potatoes infected with certain types of diseases (dry rot, for example), we use the Scale Invariant Feature Transform (SIFT)—Support Vector Machine (SVM) method. In case of inconsistent or weak lighting, the histogram of oriented gradients (HOG)—Bag-of-Visual-Words (BOVW)—neural network (BPNN) method is used. Otherwise, Otsu’s threshold binarization—a convolutional neural network (CNN) method is used. The first phase’s result depends on the conveyor’s speed, the density of tubers on the conveyor, and the accuracy of the video system. With the optimal setting, the result reaches 97%. The second phase’s outcome depends on the method and varies from 80% to 97%. When evaluating the performance of the system, it was found that it allows to detect and classify up to 100 tubers in one second, which significantly exceeds the performance of most similar systems.

Review on Macronutrient in Agronomy Crops

Macronutrients play a very important role in plant growth and development. Three main elements are nitrogen, phosphorus, and potassium (N, P, K) and are required in abundance. They must be readily available through soil medium or fertilizer. The secondary elements are sulfur, calcium, and magnesium (S, Ca, Mg). The problem of low soil fertility and poor plant nutrition does not only affect crop yields but also crop quality. Various nutrient elements influence biochemical processes and eventually affect the overall quality of various crops and their products. Depending on the amount that is available for plant uptake, these nutrients influence crop yields and quality and plants treated with absence of nutrients in the nutrient solution showed that N and Ca were the most limiting nutrients to biomass production The crop quality characteristics mostly reported to be affected by plant nutrition include: proteins, carbohydrate, sucrose and fructose content in grains, root crops, tuber crops and fruits; vitamins like beta-carotene content in fruits and tubers; moisture content at storage in cereal grains, potato tuber density; and frying colours, and fruit weight. It has been noted that essential and beneficial nutrient elements contribute to crop quality through functioning as raw materials for the synthesis of various plant components that have food value to humans and animals.

Sorghum cover crop and repeated soil fumigation for purple nutsedge management in tomato production.

Purple nutsedge (Cyperus rotundus L.) is one of the most common and troublesome weeds. Field research trials were conducted in Florida to evaluate the effects of repeated fumigation and a sorghum sudangrass [Sorghum bicolor S. bicolor var. sudanense (Piper) Stapf.] cover crop on purple nutsedge (Cyperus rotundus L.) populations over time in tomato (Solanum lycopersicum L.) production. Among the soil fumigants, DMDS + metam potassium was consistently the most effective treatment in terms of in-crop purple nutsedge control. Plots with a sorghum cover crop during the fallow period exhibited higher purple nutsedge density during the tomato growing season as well as higher purple nutsedge shoot and tuber densities during the fallow period compared to the chemical fallow. DMDS + metam potassium was the most effective fumigant for purple nutsedge control. Unexpectedly, a sorghum cover crop during the fallow period was less effective than chemical fallow for purple nutsedge management, and therefore we do not recommend the use of sorghum cover crops for weed management in fields where purple nutsedge is the major weed species.

Modified hydrological regime from the Three Gorges Dam increases the risk of food shortages for wintering waterbirds in Poyang Lake

Poyang Lake is an internationally important wintering ground for waterbirds. Since the Three Gorges Dam (TGD) began operations, the lake’s hydrological regime has been changed, which may influence the growth of submerged plants and increase the risk of food shortages for wintering waterbirds. We explored the effect of hydrological regime change in Poyang Lake on food abundance for herbivorous waterbirds using a 19-year (1999–2017) monitoring dataset of densities of Vallisneria and their tubers. Overall, food abundance decreased significantly and fluctuated considerably after the TGD started full operations in 2009. The change was significantly correlated with the autumn drought and summer flood. Densities of plants and their tubers in early winter significantly increased with higher water levels in the previous October, and significantly decreased with higher June water levels. Autumn drought magnified the negative effect of average June water levels, and the combined effect explained 86.9% of the deviance in Vallisneria density. The optimal generalized additive model (GAM) for tuber abundance (explaining 86.2% of the deviance) contained the average June water levels, tuber density two years before and the average water level of the previous October. Average water levels in June and the previous October were important predictors of food abundance. However, TGD operations have made droughts in October a norm since 2006 and resulted in more frequent June floods. It is concluded that the risk of food shortages probably has become a new norm in Poyang Lake. The results offer new information for waterbird conservation and hydrological regime management for Poyang Lake, as well as for the middle and lower reaches of the Yangtze River as a whole.

Drivers of a habitat shift by critically endangered Siberian cranes: Evidence from long-term data.

Many waterbird populations have become increasingly dependent on agricultural habitats for feeding. While habitat destruction has been proposed as a key reason forcing waterbirds to move from natural habitats to agricultural habitats, few have used long‐term data to test this hypothesis. The Siberian crane (Leucogeranus leucogeranus) is an IUCN Critically Endangered species. About 98% of its global population winters at Poyang Lake, China. Recently, many cranes shifted from feeding in natural wetlands to agricultural habitats. Here, we integrate bird surveys, Vallisneria tuber (the traditional food of cranes in natural wetlands) surveys, water level data, and remotely sensed images from 1999 to 2016 to explore the drivers of this habitat shift. Changes in Siberian crane numbers in natural wetlands and agricultural fields indicated that the habitat shift occurred in the winters of 2015–2016. Analyses using generalized linear mixed models suggested that crane numbers in natural wetlands were positively related to tuber density and the interaction between dry season (October–March) water level and tuber density. The changes in tuber density and dry season water level in 2015–2016 indicated that tuber disappearance may have been the primary driver of the habitat shift, with a smaller effect of high water level. Submerged plants at Poyang Lake have degraded seriously in the past two decades. The plant degradation at Shahu Lake, a sublake of Poyang Lake, may have been caused by high spring water, high winter temperature, and low summer temperature. However, the drivers of tuber disappearance at Poyang Lake may not be restricted to these variables. Because Poyang Lake is an important refuge for many waterbirds in the Yangtze River floodplain, it is urgent to take effective measures to restore its submerged plants and ecosystem health. Agricultural fields can be important refuges for Siberian cranes, mitigating the negative impacts of wetland deterioration.

Allometric equations for the invasive vine air potato (Dioscorea bulbifera) in its exotic range in Florida

AbstractNondestructive means for estimating air potato (also known as air yam; Dioscorea bulbifera L.) biomass will help gauge its management efficacy over time. We developed allometric equations to estimate total and fractional biomass components and densities of aerial bulbils and underground tubers of field-grown D. bulbifera in Florida. We selected four naturally infested sites representing its southern, central, and northern distribution in Florida and measured three independent variables (vine densities, stem diameters, and top heights) of 84 (21 site−1) discrete D. bulbifera patches during late October to early December of 2012. We destructively harvested D. bulbifera biomass, sorted by tubers, stems, leaves, and bulbils; counted units of bulbils and underground tubers (dependent variables); and dried to a constant weight. Mean percentages of tuber, stem, leaf, and bulbil fractions in total biomass were 42.0, 15.6, 26.0, and 16.4, respectively. We developed a parameterized multiplicative prediction model and regression equation for each dependent variable. Slopes of relationships among independent and dependent variables varied by biomass and density (bulbil and tuber) of plant components. Multiplied values of independent variables: all three for total, tuber, stem, and leaf biomass; two (vine base diameter*patch height) for bulbil biomass; two (vine density*patch height) for bulbil density; and only one (stem density) for tuber density provided best (R2-based) prediction values. These models will provide nondestructive methods for estimating biomass components and density of vegetative propagules of naturally growing D. bulbifera. Models are critical for understanding the performance of D. bulbifera in its exotic range, estimating biomass to project control costs, and comparing biomass components and bulbil/tuber densities during pre- and postmanagement periods to gauge control efficacy.

ДИНАМИКА ЭЛЕМЕНТОВ ПИТАНИЯ КАРТОФЕЛЯ В ЗАВИСИМОСТИ ОТ ГЛУБИНЫ ПОСАДКИ КЛУБНЕЙ И РАСЧЕТНЫХ НОРМ УДОБРЕНИЙ

The article discusses the impact of tuber planting density and fertilizer design norms on the dynamics of potato nutrients in the southeastern part of Volga-Vyatka zone. The density of planting tubers and the calculated norms of fertilizers have a direct impact on the dynamics of the nutritional elements of the potato content and removal of mineral nutrition elements by the potato plants on the leached chernozem of the south-eastern part of Volga-Vyatka zone. The accumulation of elements of mineral nutrition is also significantly influenced by the weather conditions formed during the growing season of potato plants. Potatoes are demanding on soil fertility. With a good harvest, it consumes and alienates a large amount of nutrients from the soil. With an increase in the density of planting tubers and the calculated norms of fertilizers, respectively, the removal of mineral nutrients also increases. Studies have shown that the highest nitrogen content in the soil was observed during the beginning of the growing season of potato plants - at the time of emergence. The maximum concentration of phosphorus reached in the phase of budding and flowering of potatoes. During the growing season of potato plants, the content of exchangeable potassium increases and reaches a maximum value in the budding phase. After flowering, the indicator of potassium in the soil began to decline and at the time of harvesting reached a minimum value.

Wintering Swan Geese maximize energy intake through substrate foraging depth when feeding on buried Vallisneria natans tubers

BackgroundForaging theory predicts that animals select patches that offer the highest net rate of energy gain. Hence, prey distribution patterns and spatiotemporal heterogeneity play important roles in determining animal feeding patch selection. For waterfowl foraging on buried aquatic plant tubers, the distribution and biomass of these plant organs vary with depth in the substrate. Since excavation costs also increase with depth, the energy intake of the animals foraging on these plants is highly sediment depth dependent.MethodsHere, using observations of Swan Geese (Anser cygnoides) foraging on Vallisneria natans tubers, we test our hypothesis that geese feeding on tubers buried at intermediate sediment depth maximize their daily energy intake because of the interaction between tuber size and abundance with depth. To do this, we measured the distribution patterns of buried Vallisneria tubers under both undisturbed conditions and post-exploitation by geese (i.e. giving-up conditions). We investigated the relationship between tuber size and burial depth, and total tuber biomass within each sediment layer in undisturbed and exploited plots. Finally, we compared modelled Swan Goose daily energy intake feeding on Vallisneria tubers buried at different sediment layers (1–10, 11–20 and 21–30 cm below the surface).ResultsDry weight of Vallisneria tubers linearly increased with burial depth, while average total dry weight density of tubers showed a unimodal relationship, peaking at intermediate levels. Not surprisingly, Swan Geese foraged most intensively on tubers buried at intermediate sediment depths, where they maximize their daily energy intake. Our results support our hypothesis that Swan Geese feeding on tubers at intermediate depths maximize their daily energy intake.ConclusionsOur study is the first to quantify foraging strategies of Swan Geese during the wintering period, emphasizing the importance of plant traits on foraging selection of belowground foragers.

Wintering Behavior of a Siberian CraneGrus leucogeranusin Niigata, Japan, with Special Regard to Food, Foraging and Vocal Habits

An immature Siberian Crane Grus leucogeranus straggled to Niigata, Japan, in late autumn 2016 and remained over winter in an area of rice fields. In this paper the bird's diet and foraging behavior during winter 2016/2017 are described. During daytime, the crane foraged alone, mostly on post-harvest rice fields where it fed almost exclusively on Water Chestnut Eleocharis kuroguwai tubers. Other foods, such as rice grains, earthworms, grasshoppers and fishes, though eaten, were negligible in the bird's diet. The density of water chestnut tubers in the foraging area was estimated to be 3.1±3.0/m2 and the biomass 2.0±2.1 g/m2. The crane's foraging behavior generally included removing any superficial covering material, digging into and removing the soil, exploring the food in the beak and then consuming it with or without rinsing it in groundwater. During foraging, the frequency of food intake varied from 4.8±2.0/10 min to 41.3±9.5/10 min. These results indicate the great significance of water chestnuts in the diet of the Siberian Crane in winter, although further study is necessary for generalization.

Aerodynamic properties of potato tubers to airflow separation from stones and clods

ABSTRACTSeparation of potato (Solanum tuberosum L.) tubers from clods and stones in a potato harvester is difficult. It is necessary to develop a better means of separation of tubers from other like size, shape, or weight objects. The study examined the aerodynamic properties of potato tubers terminal velocity, drag coefficient, Reynolds number, diameter of equivalent sphere, and volume shape factor to design a better air separator mechanism of varieties of potato tubers from stones and clods. The experimental and theoretical aerodynamic properties of potato tubers were determined and compared using a vertical wind tunnel. The tuber size class positively affected geometric mean diameter and mass of tubers. Variety affected tuber density with ‘Sante’ having a greater density than ‘Marfona’. The interaction of tuber size class and variety affected sphericity of tubers with increasing tuber size class causing reduced sphericity. In similar tuber size classes, ‘Marfona’ had greater sphericity compared to ‘Sante’ except for class 3 that opposite was true. Mean values of aerodynamic properties of varieties tested increased with increasing tubers size. Values of terminal velocity obtained for potato tubers were lower than expected for this product compared to other agricultural crops. Airflow can be used to separate tubers from stones and clods.

Кондиціювання бульб картоплі як елемент технології стабілізації їх якості

At harvesting, transporting, loading and unloading and sorting potato tubers obtained mechanical damages. As a result of injury, the vacuole shells break and the polyphenols that are in them are oxidized by the action of oxygen in the air. Substances that are formed in this way the cause of denaturation of proteins and darkening of potato tubers [1]. As a result, potato consignments can contain up to 40% of products with darkened pulp. Most of all, tubers are injured, which were stored at a lower temperature (less than 6 °C). One of the technological methods, which reduce the level of injury, is the conditioning (heating) of potatoes at elevated temperatures. It was found that increasing the temperature of tubers from 2 to 14 °C helps to reduce their level of injury from 18 to 4% [2]. The purpose of the research: development of optimal temperature regimes for conditioning potato tubers to stabilize their quality. Potato tubers of companies HZPC (Netherlands) and Solana (Germany) which apply to two groups of ripeness: medium-early and medium-ripe were investigated. Potato tubers of the investigated varieties were heated from 4 °C (storage temperature) to 6-24 ° C (temperature change interval – 2 ° C). After than in the potatoes determine density of tubers, the degree of darkening of pulp and the number of darkened tubers. As a result, it was found that in the group of medium- early varieties the optimal conditioning temperature for the Red Lady variety is 8 °C, and for Satina and Mozart – 14 °C, and in the group of medium- ripe: 14 °C for Arosa and 18 °C for Sifra. There is a close relationship between the temperature of conditioning, the degree of pulp darkening and the number of tubers with darkened pulp. Thus, the minimum amount defect in quality of potatoes due to darkening of pulp was obtained: Satina – 5% (temperature – 16 °C), Red Lady – 4% (temperature 8 and 12 °C), Mozart – 2% (temperature 16 °C), Arosa – 6% (temperature 16 °C) and Sifra 3% (temperature 20 °C). Keywords: potato tubers, injury, pulp density, conditioning temperature, pulp darkening, quality stabilization

Selected engineering properties of tiger nut as a function of moisture content and variety

Some physical and mechanical properties of two tiger nut varieties (Sariseker and Balyumru) were determined at four moisture contents. Physical properties including length, width, thickness, geometric mean diameter, mass, 1000-tuber mass, bulk density, tuber density, surface area, terminal velocity, angle of repose, porosity, and friction coefficient were affected by moisture content at a 1% probability level, excluding sphericity. All parameters decreased with a decrease in moisture content except tuber density, porosity, and firmness. Variety only had a statistically significant effect on width, geometric mean diameter surface area, and terminal velocity at different probability levels. Force, deformation, firmness, energy absorbed, and power requirement, which were investigated as mechanical properties, were also affected by moisture content at a 1% probability level. It was also found that the variety and loading position had no significant effect on firmness and energy absorbed, respectively. Varieties showed differences in terms of 1000-tuber mass, sphericity, terminal velocity and angle of repose, length, geometric mean diameter, surface area, porosity, force, and energy absorbed at different probability levels.

Energetic Carrying Capacity of Riverine and Connected Wetlands of the Upper Illinois River for Fall-Migrating Waterfowl

Abstract The Illinois River historically provided high-quality habitat for a variety of migratory birds but sedimentation, management for commercial navigation, and increasing hydrologic variability have contributed to reductions in aquatic vegetation and naturally occurring foods for waterfowl. Cover of aquatic vegetation within the Illinois River Valley (IRV) declined during the 1950s, and it has not recovered in its historical range. The Dresden and Starved Rock reaches of the Illinois River, unlike other reaches in the IRV, still retain aquatic macrophytes in the main channel and connected backwater wetlands. To determine energetic carrying capacity of seeds and tubers for waterfowl in the upper Illinois River, we collected benthic core samples from random locations throughout the Dresden and Starved Rock reaches in falls 2013–2014. All sampling locations (i.e., main channel and connected backwater wetlands) had low mean density of seeds and tubers (<175 kg/ha) and duck energy days (DED; <1200 DED/ha)...

Twelve years of repeated wild hog activity promotes population maintenance of an invasive clonal plant in a coastal dune ecosystem.

Invasive animals can facilitate the success of invasive plant populations through disturbance. We examined the relationship between the repeated foraging disturbance of an invasive animal and the population maintenance of an invasive plant in a coastal dune ecosystem. We hypothesized that feral wild hog (Sus scrofa) populations repeatedly utilized tubers of the clonal perennial, yellow nutsedge (Cyperus esculentus) as a food source and evaluated whether hog activity promoted the long‐term maintenance of yellow nutsedge populations on St. Catherine's Island, Georgia, United States. Using generalized linear mixed models, we tested the effect of wild hog disturbance on permanent sites for yellow nutsedge culm density, tuber density, and percent cover of native plant species over a 12‐year period. We found that disturbance plots had a higher number of culms and tubers and a lower percentage of native live plant cover than undisturbed control plots. Wild hogs redisturbed the disturbed plots approximately every 5 years. Our research provides demographic evidence that repeated foraging disturbances by an invasive animal promote the long‐term population maintenance of an invasive clonal plant. Opportunistic facultative interactions such as we demonstrate in this study are likely to become more commonplace as greater numbers of introduced species are integrated into ecological communities around the world.

A review of effects of nutrient elements on crop quality.

The problem of low soil fertility and poor plant nutrition does not only affect crop yields but also crop quality. A review of many refereed published journal articles and books sourced from internet and libraries was conducted with the aim of highlighting the effects of plant nutrition on crop quality. Emphasis was put on elucidating the functions through which various nutrient elements influence biochemical processes and eventually affect the overall quality of various crops and their products. Nutrients reviewed in this paper included elements such as nitrogen (N), phosphorus (P), potassium (K), sulphur (S), magnesium (Mg), calcium (Ca), zinc (Zn), iron (Fe), and cobalt (Co). The crop quality characteristics mostly reported t o be affected by plant nutrition include: proteins, carbohydrate, sucrose and fructose content in grains, root crops, tuber crops and fruits; vitamins like beta-carotene content in fruits and tubers; moisture content at storage in cereal grains, potato tuber density; and frying colours, and fruit weight. It has been noted that essential and beneficial nutrient elements contribute to crop quality through functioning as raw materials for the synthesis of various plant components that have food value to humans and animals. Nitrogen and S are raw materials for protein synthesis. Others like Ca, P, Zn and Fe are involved in enzyme synthesis, activation or as electron carriers while Mg, and K are mostly involved in enzyme activation and transportation of materials such as fructose and sucrose from points of synthesis to sites of loading and hence affect quality of fruits, and root and tuber crops greatly. It has been noted that crop quality is also greatly influenced by the synergistic and antagonistic interactions in various nutrients uptake and utilization. Therefore, balanced nutrition is noted to be o f paramount importance. From this review it can be concluded that crop quality is a very important area to consider advancing and putting up resources for research since it has a huge bearing on human health and socioeconomic effect on farmers through its in fluence on marketability of crops and crop products.

NMDA receptor activation regulates sociability by its effect on mTOR signaling activity.

Tuberous Sclerosis Complex is one example of a syndromic form of autism spectrum disorder associated with disinhibited activity of mTORC1 in neurons (e.g., cerebellar Purkinje cells). mTORC1 is a complex protein possessing serine/threonine kinase activity and a key downstream molecule in a signaling cascade beginning at the cell surface with the transduction of neurotransmitters (e.g., glutamate and acetylcholine) and nerve growth factors (e.g., Brain-Derived Neurotrophic Factor). Interestingly, the severity of the intellectual disability in Tuberous Sclerosis Complex may relate more to this metabolic disturbance (i.e., overactivity of mTOR signaling) than the density of cortical tubers. Several recent reports showed that rapamycin, an inhibitor of mTORC1, improved sociability and other symptoms in mouse models of Tuberous Sclerosis Complex and autism spectrum disorder, consistent with mTORC1 overactivity playing an important pathogenic role. NMDA receptor activation may also dampen mTORC1 activity by at least two possible mechanisms: regulating intraneuronal accumulation of arginine and the phosphorylation status of a specific extracellular signal regulating kinase (i.e., ERK1/2), both of which are "drivers" of mTORC1 activity. Conceivably, the prosocial effects of targeting the NMDA receptor with agonists in mouse models of autism spectrum disorders result from their ability to dampen mTORC1 activity in neurons. Strategies for dampening mTORC1 overactivity by NMDA receptor activation may be preferred to its direct inhibition in chronic neurodevelopmental disorders, such as autism spectrum disorders.