Leaf Area Growth Rate Research Articles

Effect of Nitrogen and Humic Acid on Growth and Yield of Pakcoy (Brassica rapa subsp. chinensis) Plants

Decreased soil quality due to reduced nutrient content is one of the causes of decreasedquality and yield in plants. The use of humic acid organic matter with N fertilizer is one of the effortsto increase nutrients in the soil while increasing plant growth and yield. This research was conductedin Heuleut Village, Leuwimunding District, Majalengka Regency, from May to June 2024. Theresearch method used was the experimental method with a group-randomized design. The treatmentconsisted of 16 treatments that were repeated twice. The variables observed were plant height,number of leaves, root volume, plant fresh weight, leaf area, and plant growth rate. The resultsshowed that the use of N fertilizer at a dose of 115 kg/ha (urea 250 kg/ha) and humic acid 3 g/planthad a good effect on all variables observed. The results of soil analysis showed an increase in N-totaland C-organic.

Growth and Yield Responses of Bari Sweet Corn-1 (Zea Mays L.) to Naa at Different Nitrogen Levels

A field experiment was conducted to investigate the effect of foliar application of NAA at varying N-levels on growth and yield responses of BARI Sweet Corn-1 (Zea mays L.). The trial consisted of ten treatments viz. control = without NAA and N fertilizer; RDN (recommended dose of N fertilizer); 25 ppm NAA + RDN; 50 ppm NAA + RDN; 25 ppm NAA + 50% higher RDN; 50 ppm NAA + 50% higher RDN; 25 ppm NAA + 100% higher RDN; 50 ppm NAA + 100% higher RDN; 25 ppm NAA+ 150% higher RDN and 50 ppm NAA + 150% higher RDN. Results showed that application NAA in combination with various nitrogen (N) levels produced better growth than control but with few exceptions. Growth parameters viz. total dry mater (TDM), leaf area (LA), relative growth rate (RGR) and net assimilation rate (NAR) were recorded maximum from 25 ppm NAA in combination with RDN treatment. Findings revealed that 25 ppm NAA in combination with RDN treatment had also produced higher number of leaves per plant, specific leaf area (SLA), biomass duration (BMD) and absolute growth rate (AGR) than RDN treatment although statistically at par to each other. The maximum number of leaves per plant, shoot-root ratio and SLA although recorded maximum from 25 ppm NAA in combination with 100% higher RDN treatment but statistically similar to rest of the combined treatments. Yield attributes and yield of BARI Sweet Corn-1 showed positive response to NAA at varying N-levels with significant variations in majority of cases. The maximum number of cobs and productive cobs per plant, dry weight of cobs, length of cob, number of seed per row and cob, dry weight of tassel, yield per plant and harvest index were also obtained from 25 ppm NAA in combination with RDN treatment. However, maximum number of cobs and productive cobs per plant were also noted from 25 ppm NAA in combination with 100% higher RDN treatment. Significantly maximum yield per plant (114.41g) obtained from 25 ppm NAA in combination with RDN treatment which was 12.02% higher over RDN treatment. Out of ten treatments, foliar application of 25 ppm NAA in combination with RDN treatment produced better stimulation in growth and yield of BARI Sweet Corn-1. Bangladesh J. Bot. 53(2): 337-344, 2024 (June)

Effects of Neonicotinoid Seed Treatments on Cotton Seedling Physiology, Nutrition, and Growth

Plant growth and physiology can be affected by environmental and chemical factors that have the potential to influence yields. Among the factors that influence plant growth, neonicotinoid seed treatments have shown significant effects on plant growth, particularly in cotton. The dual benefits seen from neonicotinoids on plant growth and insect control show promise in improving cotton yields but little is known about how different seed treatments affect seedling physiology. A greenhouse experiment was undertaken to investigate how three neonicotinoid seed treatments (clothianidin, thiamethoxam, and imidacloprid) affect the physiology and growth of cotton seedlings in controlled environmental conditions. A randomized complete block design was used to examine seed treatments and an untreated control. Cotton seeds were treated, grown, and evaluated for physiological changes until the fifth true leaf-stage and measurements were taken at each of these stages. Data were collected on plant height, shoot fresh weight, leaf area, root length, and root biomass. In addition, chlorophyll pigments and nutrient analysis were performed on cotton seedlings. The seedlings of imidacloprid treated seeds had greater height, shoot fresh mass, leaf area, and relative growth rate by the fifth true leaf stage compared to other treated plants; however, clothianidin showed comparative performance at earlier stages in plant development that equilibrated over time. While all neonicotinoid seed treatments showed positive effects, imidacloprid showed the most potential as a bioactivator on plant growth.

The suppression of Ganoderma boninense on oil palm under mixed planting with taro plants

Abstract. Suwandi S, Alesia M, Munandar RP, Fadli R, Suparman S, Irsan C, Muslim A. 2024. The suppression of Ganoderma boninense on oil palm under mixed planting with taro plants. Biodiversitas 25: 1143-1150. Basal stem rot, caused by Ganoderma boninense, is highly destructive in monoculture oil palm plantations. This study evaluated Ganoderma boninense infections and oil palm growth in mixed plantings of oil palm seedlings and taro plants (Japanese, Bogor, and Indralaya taro). Ganoderma, colonizing rubber wood blocks, was inoculated into mixed plants, and the infection was compared to single-inoculated oil palm and taro plants. The interference of mixed planting with taro plants on the growth of oil palm seedlings was compared between inoculated and noninoculated mixed and single planting. Ganoderma inoculation caused simultaneous disease (dual-host infection) in mixed oil palm and taro plants. Ganoderma infection was less severe in taro plants compared to oil palm, whether in single or mixed planting. Over six months, oil palm root necrosis and disease index were reduced by 82% to 96% and 65% to 71%, respectively, while no significant effect was observed at nine months. The decay of Ganoderma-colonized wood improved by 44.1% to 84.0% in mixed planting, with no significant impact on mycelium viability. Taro plants did not inhibit oil palm growth, including plant height, leaf area, and relative growth rate of primary root length, in both the presence and the absence of Ganoderma infection. This study highlights the potential of mixed planting with taro to reduce Ganoderma disease in oil palm.

Growth and Yield of Shallot (Allium cepa L. Aggregatum Group) with Application of Amino Acid Biostimulant Dosages

Intensive shallot cultivation needs high application rates of inorganic fertilizers that can cause environmental problems. Therefore, it is essential to lessen the rate of inorganic fertilizers by environmentally friendlier approaches, such as the application of biostimulants like amino acids. The present study determined the most effective dosage and application method of amino acid biostimulant to increase shallot yield and growth while using only half the amount of inorganic fertilizers. The research was arranged in a randomized complete block design with two factors and four blocks as replications. The first factor was the dose of amino acids biostimulant (0, 0.5, 1, and 2 L/ha), and the second factor was the application method (through leaves and soil). Data were observed on nitrogen (N), phosphorus (P), potassium (K), manganese (Mn), boron (B), indole acetic acid (IAA), gibberellin, zeatin, kinetin, nitrate reductase activity (NRA), chlorophyll as well as the growth and yield of shallot. The results showed that the application of amino acids biostimulants increased IAA, gibberellin, and kinetin content in both application methods. Amino acids biostimulants increased N, P, K, B, Mn, and chlorophyll. Amino acids biostimulant 1 L/ha was the best dosage to increase leaf diameter, leaf dry weight, total dry weight, number of bulbs (5.63 per plant; 44%), and productivity (16.46 tons/ha; 33.77%). The application through the leaves improved NRA, leaf area, and crop growth rate. It was indicated that amino acid biostimulant through leaves provides a useful instrument for plant growth, allowing the reduction of inorganic fertilizer without compromising crop yields.

Effect of ethephon levels and amino acids on the growth characteristics of oat crop

A field experiment was conducted during the 2021-2022 season in an agricultural field in Basra Governorate. The aim was to study the effect of spraying ethephon and amino acids on the growth characteristics of oats (Avena sativa L.) Shifa cultivar. The experiment involved three levels of ethephon (0, 0.240, and 0.600 kg ha-1), represented by the symbols E0, E1, and E2 respectively, and two spray levels of amino acids (0 and 5 ml L-1), represented by the symbols A0 and A1. A factorial experiment was applied using the R.C.B.D (randomized complete block design) in a split plots arrangement with three replications. The results revealed significant differences in the levels of ethephon for most of the studied characteristics. The level of 0.240 kg ha-1 (E1) was superior in terms of chlorophyll content, crop growth rate, and the number of tillers, with increases of 39.07%, 39.26%, and 16.36%, respectively, compared to the control treatment (E0). Regarding the amino acids treatments, spraying at a concentration of 5 ml L-1 (A1) demonstrated significant superiority, resulting in the highest plant height, flag leaf area, chlorophyll content, and crop growth rate. This study concludes that amino acids play a crucial role in plant growth, and the combination of 5 ml L-1 amino acids with 0.240 kg ha-1 of ethephon significantly increased chlorophyll content and crop growth rate.

Synergistic regulation of the growth and fruit quality of cherry tomato by remaining fruit spikes and number of interspike leaves after pruning

In this study, we aimed to understand the synergistic effects of the number of fruit spikes and leaves between the fruit spikes on fruit quality in cherry tomatoes. We conducted a 2-factorial experiment combining three fruit remaining spike rate treatments, i.e., 4, 6, and 8 remaining fruit spike per branch (F4, F6, and F8, respectively) with three interspike leaf number treatments (1, 2, and 3 interspike leaves abbreviated as L1, L2, L3); thus, in total, nine different treatments (3 × 3) were performed (L1F4, L1F6, L1F8, L2F4, L2F6, L2F8, L3F4, L3F6, and L3F8). The results revealed that the number of fruit spikes and interspike leaves exhibited a significant effect on the relative growth rate of leaf area (RGH-LA) and leaf area index. RGH-LA increased with the increase of the remaining fruit spike number. The leaf area index was higher in L3F6 and L3F8 than in other treatments. Water use efficiency (WUE) was reduced with the increase of leaf number at the same fruit spike retention in 4 and 8 fruit spikes; however, 6 fruit spikes exhibited an opposite trend. The WUE was higher in L3F6 and L1F8 than in other treatments. Both soluble sugars and soluble proteins contents in leaves (LSP) were the lowest in L3F6. However, the contents of vitamin C, soluble solids, soluble proteins and starch, and the activities ofsucrose and sucrose synthase were the highest in L3F6. In addition, the fruit yield, single fruit fresh weight, and fruit firmness were the highest in L3F6. Correlation analysis revealed that the remaining fruit spike and number of leaves between the spikes regulated the photosynthetic characteristics, in particular carbon and nitrogen metabolism in the leaves, and fruit quality. Collectively, L3F6 exhibited the highest potential to improve photosynthetic characteristics, WUE, fruit quality (particularly sugar accumulation), and yield of cherry tomatoes.

Optimized N application improves N absorption, population dynamics, and ear fruiting traits of wheat.

Optimizing the N application amount and topdressing ratio can increase crop yield and decrease N loss, but its internal mechanisms have not been well studied, especially from the aspects of population dynamics and structure, ear fruiting traits. Here, field experiments, with three N rates 120 (N1), 180 (N2), and 240 (N3) kg N ha-1 and three N topdressing ratios T1 (7:3), T2 (6:4), and T3 (5:5) were conducted. At the same N level, results showed that the N accumulation amounts in the leaf, grain, and plant in T2 were higher than in T3 and T1, and increasing 60 kg N ha-1 (N3 compared to N2, N2 compared to N1) significantly enhanced N accumulation amounts. The effect of the N topdressing ratio on partial factor productivity of applied N was consistently T2 > T3 > T1, but T1 was more conducive to improving N utilization efficiency for grain and biomass production. After the jointing stage, compared to T1 and T3, T2 was more conducive to increasing the population growth rate of plant height, leaf area index, leaf area growth rate, dry matter weight, dry matter accumulation rate, light interception rate, and spikelets of population, and the above-mentioned indexes of population could be significantly enhanced by increasing 120 kg N ha-1. T2 increased the fruiting spikelets per ear, grains per ear, grain weight per ear, fruiting rate per ear, grain filling rate per ear, and yield but decreased the sterile spikelets at the top and bottom and imperfect grains per ear. Increasing N from 120 kg ha-1 to 180 kg ha-1 or from 180 kg ha-1 to 240 kg ha-1 significantly enhanced yield. The N accumulation amount in the grain, leaf, plant, leaf area growth rate, dry matter accumulation rate, light interception rate, population spikelets, fruiting spikelets per ear, grain filling rate, and yield were significantly positively correlated with each other. This study demonstrates a suitable N application rate with a N topdressing ratio 6:4 would more effectively improve N efficiency, population dynamics, structure, ear fruiting traits, and yield, but the effect of the N topdressing ratio is not as significant as that of increasing 60 kg N ha-1.

Effect of essential heavy metals on leaf area, absolute growth rate and flower yield of tuberose cv. ‘Prajwal’

An experiment was conducted with graded levels of three essential heavy metals viz., MnSO4, CuSO4 and ZnSO4at three different concentrations i.e., MnSO4 @ 1000, 2000 and 3000 mg kg-1 soil, CuSO4 @ 100, 200 and 300 mg kg-1 soil, ZnSO4 @ 200, 400 and 600 mg kg-1 soil in addition with no application of nutrients as well as essential heavy metals in the soil (Control). The experiment was carried out with polybag culture method and conducted with a Completely Randomized Design using three replications. Data recorded on leaf area, absolute growth rate, and flower yield of tuberose cv. ‘Prajwal’ were analyzed using OPSTAT software and the least significant difference was used to differentiate the treatments. Mean analysis of the data indicated that application of ZnSO4 @ 400 mg kg-1 soil recorded significant increase in the leaf area (209.22, 239.31 and 224.87 cm2per plantrespectively during 2018-19, 2019-20 and the pooled data analysis) and absolute growth rate (0.035, 0.109 and 0.073cmday-1 respectively during 2018-19, 2019-20 and the pooled data analysis). Asubstantial increase in the weight of single floret in tuberose cv. ‘Prajwal’ was noticed by application of ZnSO4 @ 400 mg kg-1 soil which might be attributed to the consequential increase in the leaf area and absolute growth rate, even though the analyzed data was found non-significant.

Genetic variability and plasticity of plant allometry

Abstract The metabolic scaling theory (MST) predicts quasi‐universal trait–size relationships in plants, characterised by a unique allometric exponent within and across large taxonomic scales. However, recent studies have identified variability in allometric relationships, without a clear understanding of the modulating role played by genetic variation and environment. Here, we investigated (1) the allometric relationships for two central traits of MST, namely total leaf area and plant growth rate, in the model species Arabidopsis thaliana, (2) the variability of plant allometries between genotypes and (3) the plastic responses of plant allometries under water deficit, high temperature and their interaction. Using a population of 120 genotypes, we found that intraspecific allometries adhered on average with MST predictions. However, a broad variability but a moderate plasticity in the allometric exponents was observed across genotypes and environments. Allometric exponents were impacted significantly, yet weakly, by water deficit, but not by high temperature. Moreover, genotypes that deviated from MST predictions exhibited more plasticity in trait–size relationships than genotypes that followed MST predictions. Our study suggests that plant allometry is genetically variable and might be related to different adaptive strategies to cope with stressing conditions. Thus, our results highlights the need of assessing trait–size relationships within species to understand the mechanisms of plant adaptation to contrasted environments. Read the free Plain Language Summary for this article on the Journal blog.

ANÁLISIS DE CRECIMIENTO, RENDIMIENTO DE FRIJOL AYOCOTE (Phaseolus coccineus L.) EN UN SISTEMA DE FERTILIZACIÓN NITROGENADA

<p><strong>Background</strong>. The ayocote bean (<em>Phaseolus coccineus </em>L.) is a leguminous native of the temperate zones of the Mexican territory, with great potential for use and exploitation by the population. However, information on its growth and mineral nutrition for its production is scarce. <strong>Objective.</strong> Determine the dynamics of growth, biomass production, grain yield and its components in the cultivation of runner beans in a cultivation system with nitrogen fertilization. <strong>Methodology</strong>. The trial was carried out under field conditions, under a rainfall regime during 2014 in Montecillo, State of México, México; with temperate clime. The purple runner bean cultivar was sown with applications of 0, 75 and 150 kg ha<sup>-1 </sup>of nitrogen fertilization. Variables were recorded as number of green leaves, leaf area index, total biomass and grain yield with its components. The study was developed using an experimental design that was randomized complete blocks with four replications. <strong>Results</strong>. With the treatment of 150 kg ha<sup>-1 </sup>of nitrogen, the highest values were obtained, such as the number of green leaves, 240 m<sup>2</sup>; leaf area index, 7.75; leaf area length, 277 days; total biomass, 566 g m<sup>2</sup> and grain yield 363 g m<sup>2</sup> with respect to the control. With the same treatment, the organs with the highest accumulation of dry matter were: grain and stem with 39%. <strong>Implications</strong>. Whit the supply of nitrogen, the biomass and the yield of the runner bean can be increased. This contribution can help the producers of this crop. <strong>Conclusions</strong>. The application of nitrogen to the soil increases the leaf area index, its duration, growth rate, biomass and crop yield. The highest profitability in runner beans is achieved with the application of 150 kg ha<sup>-1</sup> of nitrogen.</p>

Soil Abiotic Properties Shape Plant Functional Diversity Across Temperate Grassland Plant Communities

There is increasing awareness that plant community functional properties can be an important driver of ecosystem functioning. However, major knowledge gaps exist about how environmental factors, especially climate and soil abiotic properties, shape plant functional diversity at a regional scale. Furthermore, at those scales the relationships between plant functional and taxonomic diversity have rarely been considered. Here, we used a large database of plant species and functional trait data from 180 temperate grasslands across England, covering a broad range of grassland types, climatic conditions and management intensities, the last having a strong influence on multiple soil variables. Our specific aims were to: (1) identify the dominant environmental factors explaining variation in different facets of plant community functional properties, including community weighted means (CWMs) of functional traits and various multi-trait functional diversity indices; and (2) test whether the relationship between plant functional and taxonomic diversity is mediated by environmental factors at a regional scale. We found that soil abiotic properties (pH and nutrient stocks), but not climate, were the main environmental factors explaining grassland plant functional diversity at a regional scale, with a significant contribution of soil nutrient stoichiometry (N/P ratio). Two indices of plant community functional properties, namely CWMs of specific leaf area and relative growth rate, were explained by interactions between soil pH and N and mean annual precipitation, soil pH soil N and soil N/P ratio. These indices were also negatively related to taxonomic diversity under certain soil abiotic conditions, specifically high soil clay content, pH and N/P. Together, our results indicate that soil abiotic properties rather than climate factors shape plant functional diversity across temperate grassland plant communities at a regional scale. They also suggest that interactions between environmental factors play a significant role in shaping patterns of plant community functional properties. Our findings are of importance for the design and interpretation of future studies using trait and diversity measures as proxies of ecosystem services at regional scales.

Effect of phosphorus concentration on mineral nutrition and growth phenology in Pistacia vera L. and Pistacia atlantica Desf.

• The treatment 5 ppm enhance P. atlantica establishment. • Increasing phosphorus concentrations in the soil enhanced P, K, Fe, Mg, Na and Cu uptakes in both species. • High P level reduced Zn uptake. • P. atlantica can rehabilitate the exploited phosphate zones. This study was performed to evaluate the effect of phosphorus (P) on two pistachio species Pistacia vera L. ( P. vera L.) and Pistacia atlantica Desf . ( P. atlantica Desf.) growth, phytomass production and nutrient uptake, recorded 82 days after treatment. The plants were grown in pots containing soil supplied with six levels of phosphorus 0, 5, 15, 30, 60 and 120 mg/L as phosphoric acid (P 2 O 5 ). Results showed that P has a major effect on minerals uptake, leaf area and relative growth rate of (shoot, root and root/shoot phytomass ratio) in P. vera and P. atlantica . The two species showed different patterns. P level (5 mg/L) increased significantly P. atlantica leaf area and relative growth rate compared to low phosphorus level (0 mg/L) and high P level 60 and 120 ppm. Indeed, high P level 60 and 120 mg/L reduced significantly these parameters in both species. This study suggested that P applications at 5 mg/L enhance P. atlantica establishment. Also, P. atlantica maintained growth at 15, 30 mg/L. Increasing phosphorus concentrations in the soil enhanced P, K, Fe, Mg, Na and Cu uptakes in both species. In contrast, high P level reduced Zn absorption. Added to P. atlantica adaptation to water and salinity stress, this finding has major implications in arid land rehabilitation, where many soils have high P levels and suffering from aridity.

Drip Fertigation with Relatively Low Water and N Input Achieved Higher Grain Yield of Maize by Improving Pre- and Post-Silking Dry Matter Accumulation

Appropriate irrigation and nitrogen (N) management strategies are necessary to achieve a sustainable yield of maize with relatively low water and N inputs. Here, a 2-year field experiment with two irrigation methods (drip irrigation and flood irrigation) and five N application rates (0, 225, 300, 375, and 450 kg N ha−1) was conducted to evaluate maize yield and water and N use efficiency in the North China Plain (NCP). Compared with flood fertigation (FF), drip fertigation (DF) improved the soil water content (SWC) in the 0 to 40 cm soil layer and maintained a greater soil mineral N content (Nmin) of that soil layer. This resulted in increased soil Nmin in the 0 to 40 cm soil layer for the 375 kg ha−1 (N3) under DF compared with the 450 kg N ha−1 (N4) treatment under FF during both pre- and post-silking of maize. The maize crop accumulated greater N at both pre- and post-silking compared using N3 under DF compared to N4 under FF. Greater pre-silking N accumulation increased both leaf area and plant growth rate, leading to more dry matter (DM) accumulation and develop more kernels, while sufficient post-silking N accumulation maintained high leaf area to produce more DM post-silking and promote maize ability to support grain filling. As a result, maximum maize yield (10.4 Mg ha−1) was achieved due to increased kernel number and kernel weight for N3 (375 kg N ha−1) under DF with a 20% reduction in N fertilizer input compared with the N4 (450 kg N ha−1) treatment under FF. Due to greater grain yield and N uptake and less water consumption, the agronomic N efficiency (AEN), N partial factor productivity (PFPN), water use efficiency (WUE) and net income for the N3 treatment under DF increased by 30.4%, 28.6%, 58.3% and 11.0% averaged over two years, respectively, compared to the N4 treatment under FF. Therefore, drip fertilization could improve maize grain yield with a relatively lower water consumption and N application rate compared with flood irrigation with higher N fertilization, as well as increase the economic benefits.

Water regimes on soil covered with plastic film mulch and relationships with soil water availability, yield, and water use efficiency of papaya trees

Plastic film mulches have the potential to be used in papaya production, mainly aiming to reduce water application in semi-arid regions. However, there is a lack of technical information and the need to introduce mulching practices in papaya orchards. The objective of this work was to evaluate the effects of plastic film mulch and irrigation depths on soil water availability (SWA), stomatal conductance, leaf temperature, and agronomic traits of papaya trees. The study was carried out during 2018 and 2019 in Jaíba city, located northern Minas Gerais state, in the Brazilian semi-arid region. The experiment was a split plot design, with soil cover conditions assigned to the plots (bare soil and mulched soil) and water replenishment levels to subplots (25%, 50%, 75%, 100% and 125% of crop evapotranspiration [ETc]). Plants were drip irrigated with water replenishments based on climate data. Soil moisture was measured along time and agronomic and physiological characteristics of papaya trees, as well. Water tensions were higher in treatments with lower water replenishments. Results showed that the increase in irrigation depth favors leaf-area growth rate, stomatal conductance, yield, and water footprint of papaya. The use of mulch together with the increase in water replenishment levels contributes for maintenance of the soil water content between the upper limit of SWA and 75%SWA. The use black plastic mulching with drip irrigation in medium-textured soil saves up to 152 L of water per Kg of fruit, and increase productivity up to 34% by replenishing the crop evapotranspiration every irrigation event. The use of black plastic as ground cover is technically feasible for keeping soil water availability above 75% by irrigation supply of at least 75% of ETc on sand-clay-loam soil.

The potential of Central Java local black rice and red rice as drought tolerant cultivars

Black and red rice contain nutritional values not found in white rice. They contain anthocyanins which are beneficial to health. Drought stress can potentially reduce rice yield. So, it is necessary to develop local black and red rice into tolerant cultivars. This study used a completely randomized design (CRD) with cultivar factor (V) and drought stress level (K). Drought stress treatment was carried out when the plants were 35-95 DAP (days after planting) using the modified gravimetric method. Plant destruction was conducted at 7 and 21 DAT (days after treatment) to measure the growth analysis component. The observation of the growth analyses was plant dry weight, leaf area (LA), specific leaf area (SLA), relative growth rate (RGR), and net assimilation rate (NAR). Agronomic characters by observing shoot-root ratio and flowering age. The results showed drought stress decreased plant dry weight, leaf area, and relative growth rate on Sragen black rice. Jelitheng Karanganyar showed high RGR and NAR under drought stress and the fastest flowering age response. Wonogiri black rice gave the growth response by reducing specific leaf area. The highest shoot-root ratio was shown on Wonogiri black rice.

Nitrogen and weed management effects on weeds and yield of barley in Kandahar, Afghanistan

Growth and yield of barley (Hordeum vulgare L.) are highly influenced by nutrients and weed management. Nitrogen (N) is the most crucial nutrient to which barley crop responds readily. Efficient management of N and weeds can provide higher yield, better quality, and higher income to the farmers. Therefore, a field experiment was conducted in a split-plot design with three replications during winter season of 2019-20 in the Afghanistan National Agricultural Sciences and Technology University (ANASTU), Kandahar, Afghanistan to evaluate the effect of weed and N management on weeds growth and barley productivity. There were three weed management options in main plots, such as weedy check, herbicide use alone [post-emergence application (PoE) of clodinafop-propargyl 60 g/ha + metsulfuron-methyl 4 g/ha (tank-mix) at 30 days after sowing (DAS)], and integrated weed management (IWM) involving stale seed bed 15 days before sowing + wheat crop residue (2.5 t/ha) retention + clodinafop-propargyl + metsulfuron-methyl (tank-mix) PoE with half of the recommended dose at 30 DAS]. Four N levels (~0, 40, 80 and 120 kg N/ha, i.e., N0, N40, N80 and N120) were included as sub-plot treatments. The IWM led to significantly lower density and biomass of weeds at 40 and 70 DAS and significantly increased weed control efficiency (WCE) and weed control index (WCI). Clodinafop-propargyl (60 g/ ha) + metsulfuron-methyl (4 g/ha) (tank-mix) PoE also resulted in significantly lower density and biomass of weeds and higher WCE and WCI than weedy check at all stages. IWM being at par with clodinafop-propargyl + metsulfuron-methyl (tank-mix) PoE led to higher growth (crop height, dry weight, leaf area index and growth rate) and yield of barley. On the contrary, the effect of nitrogen levels was not significant on the weed density and biomass reduction. N120 and N80 were comparable with respect to growth, yield attributes and yield of barley. Thus, IWM with 80 kg N/ha may be recommended for better weed management and higher barley yield and income in Kandahar, Afghanistan.

Comparative study of two bioassays with weakened duckweed and yeast treated with homeopathic preparations

In homeopathic basic research, the question as to the most adequate test systems and apt methodology is still open.
 This investigation examined the hypothesis that more complex organisms show stronger reactions to homeopathic remedies than less complex ones.
 We compared two Arsenic (As5+) stressed bioassays with duckweed (Lemna gibba, a multi-cellular autotrophic organism) and yeast (Saccharomyces cerevisiae, a single-cellular heterotrophic organism) regarding their response to homeopathic preparations [1].
 For duckweed, growth rates of leaf area and leaf number were evaluated. For yeast, growth kinetics were determined by measuring slope, yield and Et50 (point in time when yield was half maximum) of the sigmoid growth curve. The experiments with duckweed and yeast were performed in parallel (same day, same location and identical homeopathic preparations).
 After screening 17 substances, three homeopathic preparations (Arsenicum album, nosode, gibberellic acid) were chosen for repeated experimental series [2]. Five independent experiments were conducted for each remedy with both organisms in parallel. Potency levels used were in the range of 17x–33x for duckweed and 17x–30x for yeast. To control for test system stability, systematic negative control experiments were conducted over the complete experimentation period. All experiments were blinded and randomized.
 The systematic negative control experiments did not yield any significant effects. Application of potentized Arsenicum album in the duckweed bioassay yielded the largest effects compared to water controls without remedies for the parameters leaf area and leaf number (p

Renewable organic waste as substrate conditioning for the production of Euterpe oleracea seedlings

Forest restoration has the premise of restoring degraded native vegetation to conditions prior to degradation. The objective of this work was to evaluate the production of seedlings of a native species from the Amazon biome (Euterpe oleracea) under different substrates. The experiment was carried out at the Federal University of Tocantins, using a completely randomized design, and a 5x 4 factorial scheme, with five substrates (babassu stem + soil, babassu stem + rice husk + soil, coconut fiber + soil, babassu stem + fiber coconut + rice husk + soil, commercial substrate + soil - control), four trial periods (50, 100, 150 and 200 days). The evaluated variables: plant height, stem diameter, shoot dry matter, root dry matter, total dry matter, seedling quality index, leaf area and absolute growth rate. The growth of assai seedlings was influenced by the different substrates, until the 150 days after transplanting the quality and development of the seedlings were the same, both for the treatments that used commercial substrate and for the treatments that used renewable materials in their composition. The treatment using babassu stem (T1) obtained better shoot dry matter, total dry matter and seedling quality index values, in addition to being a material found in abundance in the regions, making this treatment the most viable and recommended for the production of assai seedlings.

Impact of Trichoderma asperellum on Chilling and Drought Stress in Tomato (Solanum lycopersicum)

The acceleration of climate change is necessitating the adoption of shifts in farming practices and technology to ensure the sustainability of agricultural production and food security. Because abiotic stresses such as drought and chilling represent major constraints on agricultural productivity worldwide, in this study, the mitigation of such stresses by the fungus Trichoderma asperellum HK703 was evaluated. The fungus was grown on whole grain oats, kaolin and vermiculite for 5 days and then the formulation was mixed with the potting soil to colonize the roots of the plants. The effect of the bioinoculant on tomato under drought or chilling was analyzed in tomato (Solanum lycopersicum) plants. Leaf, stem and root succulence, electrolyte leakage, the relative growth rate of plant height, stem thickness and leaf area, as well new leaf emergence and chlorophyll content were determined. The results showed that drought or chilling increased electrolyte leakage and reduced plant growth and development traits and chlorophyll (a,b) content. However, inoculation with T. asperellum eliminated or reduced most of the negative impacts of drought compared to the non-stressed plants, with the exception of chlorophyll b content. Furthermore, inoculation with T. asperellum improved some of the evaluated features in chilling stressed plants but had no effect on plant height or chlorophyll (a,b) content. The results of this study indicate that T. asperellum was more effective in alleviating drought than chilling stress in tomato plants.