Total Root Dry Weight Research Articles

Early-season maize responses to salt stress: Morpho-physiological, leaf reflectance, and mineral composition

Salt stress is a major environmental factor that affects maize production. The impact of salt stress during the early vegetative stage inhibits growth and development. In this study, two maize hybrids, A6659 and P1316, were subjected to five salinity treatments with electrical conductivity 0, 3, 6, 9, and 12 dS m−1 for 28 days. A total of 26 traits were evaluated, including morpho-physiological, biomass, leaf reflectance, and mineral composition in two independent studies. Under salt stress, stomatal conductance and transpiration were reduced, resulting in a canopy temperature rise of 4 °C. A higher salinity level (12 dS m−1) reduced plant height (47%) and total leaf area (44%), consequently reducing total shoot dry weight (37%) and total root dry weight (24%). Leaf minerals such as potassium, magnesium, and phosphorous declined with increasing salt concentrations. The elevated salt concentration in the rhizosphere caused an increase in leaf reflectance at the near-infrared (NIR) region, which is attributed to macronutrient deficiency under stress conditions. The results demonstrated that maize could withstand salt stress up to 3 dS m−1, beyond which plant performance declines depending on the genetics. This study provides insights into key traits that can be used for screening or breeding maize for early-season salt stress tolerance.

Response Water Productivity and Sorghum Yield to Deficit Irrigation Under Surface Drip Irrigation System

A field experiment was conducted during the spring season of 2022 in a clay loam soil at the experimental station of the College of Agricultural Engineering Sciences, University of Baghdad - Al-Jadriya, in order to study the effect of deficit irrigation on the growth and productivity of Sorghum, using the surface drip irrigation system, the experiment included irrigation treatments with six levels of full irrigation treatment FI100 When 50% of the available water is depleted, it is compensated by the American evaporation basin class A, from which the deficit irrigation treatments 80, 70, 60, 50, and 40% of the complete irrigation were applied, using the RCBD with three replications. The treatments were applied during the included plant growth stages (vegetative growth, flowering and maturity). Crop growth indicators were measured at the end of the season. Sorghum seeds were sown on 3-13-2022 and harvested on 7-15-2022. The results showed that the seasonal water consumption of corn reached its highest value when the full irrigation treatment was 487.24 mm when 50% of the available water was depleted, then it decreased to 413.59, 376.94, 340.29, 303.63, and 266.98 mm for the deficit irrigation treatments (80, 70, 60, 50, and 40%) calculated from the control treatment (FI%100). Irrigation treatment (FI 100%) gave the highest values for average plant height, leaf area, chlorophyll content, total root dry weight and yield. Water consumption amounted to 413.59 and 376.94 mm compared to the full irrigation treatment, while the treatments (60, 50 and 40) % of the full irrigation were superior in that they saved an amount of water at the expense of low crop productivity. The highest water productivity was recorded at two irrigation treatments minus 80 and 70% for the Sorghum bicolorcrop. It amounted to 13.71 and 15.13 kg m3, as the lack of 20 and 30% of the irrigation water did not affect the productivity. It is recommended to irrigate at a rate of 80 and 70% of the total ETa, which indicates the possibility of providing 20 and 30% of the full irrigation needs without affecting the grain yield.

Growth and Yield of Urdbean Influenced by Vermicompost and Vermiwash

The field experiment was conducted at Agronomy farm, S.K.N. College of Agriculture, Jobner (Rajasthan) to evaluate the Growth and yield of urdbean [Vigna mungo (L.) Hepper] influenced by vermicompost and vermiwash. The field experiment was carried out during the Kharif season, 2020 on loamy sand soil. The experiment comprising 20 treatment combinations with different doses of vermicompost (control, vermicompost 1.5 t/ha, vermicompost 3.0 t/ha, vermicompost 4.5 t/ha and vermicompost 6.0 t/ha,) and foliar spray of vermiwash (control, vermiwash 5%, vermiwash 10% and vermiwash 15%) was carried out in a 3 times replicated factorial randomised block design. The research explored the effect of various doses of vermicompost and vermiwash on different growth parameters and yield of urdbean on various stages. Results revealed that application of vermicompost 4.5 t/ha significantly enhanced the growth attributes of urdbean viz., plant height, number of branches/plant, dry matter accumulation at 50 DAS and at harvest, CGR (Crop Growth Rate), LAI (Leaf Area Index), chlorophyll content, number of total and effective root nodules, fresh and dry weight of nodules. It also recorded significantly higher seed, stover and biological yields (940, 1920 and 2860 kg/ha) over lower levels. However, it was seen to be at par with vermicompost 6.0 t/ha. Results further showed that application of vermiwash 15% foliar spray at the time of flower initiation stage also resulted in significant increase in the above all mentioned growth parameters as well as recorded highest yield.

Interacting Effects of CO2, Temperature, and Nitrogen Supply on Photosynthetic, Root Growth, and Nitrogen Allocation of Strawberry at the Fruiting Stage

To efficiently improve the productivity of strawberries under growing environmental change, the photosynthesis, root growth, and nitrogen allocation of strawberries (Fragaria × ananassa Duch. cv. Toyonoka) were investigated in a factorial design of CO2, temperature, and nitrogen supply. Elevated CO2 decreased the maximum CO2 assimilation rate (Amax), maximum CO2 carboxylation capacity per unit leaf area (Vcmax), and maximum CO2 carboxylation capacity per unit leaf mass (Vcm-m) by 20%, 24%, and 44%, respectively. Meanwhile, it reduced the SPAD value, maximal fluorescence level in the dark-adapted state (Fm), and maximal photochemical efficiency of PSII (Fv/Fm). Moreover, root branches, root number, root dry weight, and nitrogen-use efficiency were further increased in response to elevated CO2 under low nitrogen. When elevated CO2 was applied together with nitrogen nutrients, the Vcm-m and root nitrogen concentration (RNC) declined by 32% and 12%, respectively, but the total root dry weight (TRDW) increased by 88%. If the nitrogen nutrient was individually applied, the TRDW decreased by 16%, while the RNC increased by 21%. When the high temperature was individually applied, the TRDW increased by 104%, but the RNC decreased by 5%. Overall, elevated CO2 exacerbated photosynthetic down-regulation and significantly affected nitrogen redistribution among strawberry organs, reducing leaf nitrogen concentration and accelerating leaf senescence. However, it could increase seed quantity and improve its quality as well. In other words, under nitrogen-deficient conditions, elevated CO2 could improve the survival of offspring via the cost of the mother plant’s growth capacity.

Pengaruh Berbagai Media Tanam Berbasis Limbah Kelapa Sawit terhadap Pertumbuhan Bibit Kelapa Sawit (Elaeis guineensis jacg) Pre Nursery

Oil palm (Elaeis guineensis Jacg.) is the top row of the largest plantation commodities and benefits from various things such as supporting the country's foreign exchange and also absorbing labor. This study aims to determine the effect of various planting media based on palm waste on the growth of pre nursery oil palm seedlings. This study used a simple randomized block design, consisting of 5 treatments which were repeated 3 times and each replicate contained 3 plant samples to obtain 45 polybags of plant samples. Observational data for each parameter were analyzed using the ANOVA test with a significant level of 5%. If there is a significant effect between the treatments, a further test will be carried out with a level of 5%. Parameters observed were plant height, stem diameter, number of leaves, leaf area, total fresh weight of roots, total dry weight of roots, and dry weight of roots. The results showed that the T3 treatment gave better results on the variable growth parameters: plant height 20.57 cm, stem diameter 7.53 mm, number of leaves 4.56 and leaf area 122.15 cm2 at 12 WAP observations. The results showed that the T3 treatment gave better results on the variable parameter observations total fresh weight of 11.09 grams, fresh root weight of 3.89 grams, total dry weight of 3.62 grams and root dry weight of 1.18 grams.

Growth and Nutrient Concentration of Lychee Grown on an Acid Ultisol

Little is known about the adaptability of lychee (Litchi chinensis) to acidic soils high in aluminum (Al). A 2-year greenhouse study was conducted to determine the effects of various levels of soil Al on dry matter production, plant growth, and nutrient concentration in shoots of lychee cultivar rootstock seedlings (maternal half-sibs) of cultivars Brewster, Bostworth-3 (Kwai May Pink), and Kaimana. Soil Al treatments were statistically different for all variables measured in the study but not rootstock seedlings. Total leaf, stem, and root dry weights significantly decreased at soil Al concentrations ranging from 0.42 to 12.69 cmol·kg−1. Increments in soil Al resulted in a significant reduction in the concentration of leaf calcium and phosphorus and a significant increase in leaf Al in cultivar rootstock seedlings. The concentration of leaf potassium, magnesium, iron, zinc, and boron were in the optimum range for lychee, whereas leaf nitrogen and manganese concentrations were above optimum. The results of this study demonstrated no cultivar rootstock seedlings differences for dry matter production in lychee trees grown under Al stress and demonstrate that lychee is highly susceptible to acid soils.

Heat and drought priming induce tolerance to subsequent heat and drought stress by regulating leaf photosynthesis, root morphology, and antioxidant defense in maize seedlings

Novel stress tolerance strategies, such as heat and drought priming, are widely used in plants to increase tolerance to subsequent stresses. To date, it is still not known whether heat, drought, and combined stress priming can improve the tolerance of maize plants to heat, drought, and combined stresses by improving the morphology and distribution of roots and antioxidant defense mechanisms in maize seedlings. Here, seedlings of maize were firstly twice exposed to heat, drought, and combined stress at 33 °C/25 °C and 50–60% of soil water holding capacity (SWHC) followed by temperature and water recovery, and then subjected to more severe heat, drought, and combined stress at 36 °C/28 °C and 45–55% of SWHC. Under individual heat or drought stress, healthy values of gas exchange and chlorophyll fluorescence parameters, leaf relative water content, leaf water potential, and leaf cooling were significantly reduced, while superoxide anion and MDA contents in roots were significantly increased. Combined heat and drought stress usually exhibit a typical superimposed effect for the abovementioned parameters. Plants with heat, drought, and combined stress priming improved the redox balance of maize roots by enhancing the activities of superoxide dismutase, peroxidase, and catalase, initiated increases in root vitality as well as osmoregulatory substance contents as evidenced by increased soluble sugar, soluble protein, and proline contents. Principal component analysis revealed a strong correlation between antioxidant enzyme activities and osmoregulatory substance contents in roots. The combined stress priming effectively increased total root length, total root surface area, total root volume, and total root dry weight when compared with no priming. Combined stress priming optimized root distribution, leading to an increase in root length density and root dry weight density in the 12–18, 18–24, and 24–30 cm soil layers. Additionally, a strong positive correlation was observed between leaf relative water content, leaf water potential, and leaf cooling, indicating that better leaf water relations in the primed plants were conducive to the improvement of leaf cooling capacity, which provides good conditions for the increase in photosynthetic rate to maintain the integrity of the maize plant. The significant increases in leaf area, specific leaf weight, aboveground dry mass, and a significant reduction in leaf rolling in combined stress-primed plants indicated that the negative effects of heat and drought stress can be effectively mitigated. The current data indicated that the beneficial stress memory induced by priming in maize seedlings developed their defense systems to trigger more effective clearance mechanisms against subsequent combined heat and drought stress. These findings provided evidence that heat, drought, and combined stress priming enhanced maize adaptability to subsequent heat, drought, and combined stress by improving the morphology, distribution, and antioxidant capacity of the root system. • The effects of combined heat and drought stress on leaf water relations, photosynthesis, , and root physiological activities were studied. • Combined stress-primed plants acquired a stress imprint. • The enhanced tolerance of primed plants to heat and drought stress may be attributed to improved physiological activities in roots.

EVALUATION OF WATER STRESS AND CO-INOCULATION OF AZOSPIRILLUM BRASILENSE AND RHIZOBIUM TROPICI IN BEANS (PHASEOLUS VULGARIS L.)

Climate change has caused major changes in abiotic factors, with water stress as the greatest threat to agricultural production. The measures aimed at alleviating the problems caused by this limiting production factor have occurred through the adoption of sustainable strategies, especially microbial biotechnology, which uses the interactions between the microorganism and the plant, ensuring productive quality and inducing plant resistance to stresses biotic and abiotic. The objective of the present work was to evaluate the biological nitrogen fixation and the development of bean seedlings, with co-inoculation of two types of inoculants, which were subjected to water stress by different pot capacities. The experiment was conducted in a greenhouse, at Universidade Paranaense - UNIPAR, from April to June 2019. The experimental design was completely randomized (DIC), with 5 replications, 16 treatments and 80 experimental units. The cultivar used was SCS Riqueza. The parameters evaluated were pot capacity (25%, 50%, 75% and 90%); small, large and total nodules, shoot and root length, dry and fresh weight, total carbon and nitrogen. The evaluation of the morphological parameters of the bean seedlings indicated that the co-inoculation technique promoted beneficial effects for the dry mass parameters of shoot, nodule and root. The analysis of the percentage of carbon and nitrogen in the tissues of the seedlings provided an increase in the concentration of these elements in treatments that involved co-inoculation (Azospirillum brasilensis and Rhizobium tropici) with pot capacities of 25 and 75% (CV), demonstrating that the association of microorganisms is beneficial in the limiting water situation.

Influence of Rhizobium inoculation and phosphate rock fertilizer application on growth and yield components of green gram in Tharaka-Nithi county, Kenya

Green gram is an important drought tolerant grain legume crop in Kenya. In Tharaka Nithi County green gram is as a major source of food security. Hence, there is need for a cheap and sustainable system of agricultural production is needed to increase its production. The legume/Rhizobium symbiosis in combination with phosphate rock offers a natural system for improving green gram nitrogen fixation. Therefore, this study was aimed at determining the effect of Rhizobium and phosphate rock fertilizer application on growth and yield attributes of N26 and KS20 varieties. The study was carried out at Chuka University Horticultural Research Farm for two seasons, November 2019 to January 2020 and February to April 2020. Factorial experiment of 2x2x2 was laid out in a Randomized Complete Block Design (RCBD). There were three factors, variety (N26 and KS20), phosphate rock (0 and 30 kg P ha-1) and Rhizobium MEA 716 (0 and 100 g ha-1). The experiment contained eight treatments which were replicated three times. The data was collected fortnightly on four randomly selected plants on parameters such as plant height, number of leaves, branches, pods, total dry biomass, shoot and root dry weight and grain yield. These data were analyzed using Statistical Analysis Software (SAS). Significant means are separated using Least Significant Difference (LSD) at probability level of 5%. Results for both seasons indicated that combined application of Rhizobium MEA 716 Rhizobium 100 g ha-1 and phosphate rock 30 Kg ha-1 phosphate under variety in treatment (R1P1KS20) showed significantly (P<0.05) higher plant height (76.07 cm), number of branches (14.08 plant-1), shoot dry biomass (52.01 g plant-1), root dry biomass (7.60 g plant-1), total dry biomass (146.4 g plant-1), number of pods (84 plant-1) and yield (2158 kg ha-1) compared to variety N26 in treatment (R1P1N26). Therefore, combination of Rhizobium MEA 716 100 g ha-1 and phosphate rock 30 Kg ha-1 under variety KS20 led to improved growth attributes equally yield components of KS20 variety over N26. From these findings, application of Rhizobium MEA716 at 100 g ha-1, and 30 Kg ha -1 phosphate rock under variety KS20 was recommended for improved and a sustainable green gram production in the study area.

Effect of Rhizobium Inoculation and Phosphate Rock Fertilizer Application on Biomass Production, Nutrient use Efficiency and Yield Parameters of Green Gram (Vigna radiata)

The research was focused on an ecologically sound and highly production of legumes particularly green gram through the application of Rhizobium and rock phosphate fertilizer. Therefore, biomass production, nutrient use efficiency and yield parameters were determined for two growing seasons (November 2019 - January 2020 and February - April 2020), at Chuka university horticultural research farm. Biological nitrogen fixation (BNF) in green grams can improve sustainable soil fertility management and increased production. In Kenya, green gram is a major source of food security particularly in Tharaka Nithi County. However, green gram yields are usually low due to low phosphorous and nitrogen levels of the soil. A factorial experiment of 2 x 2 x 2 was laid out in a randomized complete block design. There were three factors, varieties (N26-nylon and KS20-uncle), phosphate rock (0 and 30 kg P ha-1) and Rhizobium MEA 716 (0 and 100 g ha-1) making a total of eight treatments which were replicated three times. Soil sampling and analyses were done before planting and after harvesting of green grams. Data on grain yield, total dry biomass, shoot and root dry weights. Phosphorus use efficiency (PUE) and nitrogen use efficiency (NUE) were done. Data was analysed using Statistical Analysis Software (SAS). Significant means were separated using Least Significant Difference (LSD) at probability level of 5 %. Results for both wet and dry seasons indicated that variety KS20 under Rhizobium inoculation and phosphate rock fertilizer (R1P1V2) showed significantly (P<0.05) higher increase in shoot dry biomass (52.01 g plant-1), root dry biomass (7.60 g plant-1), total dry biomass (146.4 g plant-1), number of pods (84 plant-1) and yield (2158 kg ha-1). Also, there was significant (P<0.05) higher phosphorous use efficiency of 279.32 Kg/ha and nitrogen use efficiency of 1732 kg/ha in treatment R1P1V2 over other treatments. From these results it was concluded that variety KS20 (V2) performed better compared to N26 (V1) under combined application of Rhizobium and phosphate rock fertilizer. Hence, based on the findings, for sustainable and improved green gram production farmers in Tharaka Nithi County.

Drought tolerance assessment of citron watermelon (Citrullus lanatus var. citroides (L.H. Bailey) Mansf. ex Greb.) accessions based on morphological and physiological traits

Long-term cultivation of citron watermelon under water-constrained environments in sub-Saharan Africa resulted in the selection and domestication of highly tolerant genotypes. However, information on the magnitude of variation for drought tolerance in citron watermelon is limited for the effective selection of suitable genotypes for breeding. The objective of this study was to determine variation for drought tolerance among South African citron watermelon landrace accessions for selection and use as genetic stock for drought-tolerance breeding in this crop and closely-related cucurbit crops. Forty genetically differentiated citron watermelon accessions were grown under non-stress (NS) and drought-stress (DS) conditions under glasshouse environment. Data of physiological (i.e., leaf gas exchange and chlorophyll fluorescence parameters) and morphological traits (i.e., shoot and root system architecture traits, and fruit yield) were collected and subjected to various parametric statistical analyses. The accessions varied significantly for assessed traits under both NS and DS conditions which aided classification into five groups, namely; A (highly drought-tolerant), B (drought-tolerant), C (moderate drought-tolerant), D (drought-sensitive) and E (highly drought-sensitive). Drought-tolerant genotypes produced more fruit yield with less water compared with drought-sensitive genotypes. Several physiological and morphological parameters correlated with fruit yield under DS condition namely: instantaneous water-use efficiency (r = 0.97), leaf dry weight (r = 0.77), total root length (r = 0.46) and root dry weight (r = 0.48). The following accessions, namely: WWM-46, WWM-68, WWM-41(A), WWM-15, WWM-64, WWM-57, WWM-47, WWM-37(2), WWM-79, WWM-05 and WWM-50) were identified as highly drought-tolerant and recommended for drought-tolerance breeding in this crop or related cucurbit crops such as sweet dessert watermelon.

EFFECT OF INTEGRATED NUTRIENT MANAGEMENT ON SYMBIOTIC EFFICIENCY AND SOIL FERTILITY UNDER GREEN GRAM [VIGNA RADIATA (L.) WILCZEK] CULTIVATION

A field experiment was conducted at Instructional Farm (Agronomy), RCA, Udaipur, (Rajasthan) during Kharif, 2014 on clay loam soil to study the effect of integrated nutrient management on symbiotic efficiency and fertility status of post-harvest soil under Green gram cultivation. The experiment was laid out according to a factorial randomized block design with three replications. The experiment comprised four fertility levels (75% RDF, 75% RDF+VC @ 2 t ha-1, 100% RDF and 100% RDF+VC @ 2 t ha-1) and four biofertilizers levels (control, Rhizobium, PSB and Rhizobium + PSB). The RDF was 20 kg N and 40 kg P2O5 per hectare. The soil of the experimental site was clay loam in texture, slightly alkaline in reaction, medium in available nitrogen and phosphorus, while high in potassium and DTPA extractable micronutrients sufficiently above the critical limits. The application of fertility level significantly increased the number of total and effective root nodules, fresh and dry weight of root nodules and leg haemoglobin content in root nodules upto 75% RDF+VC @ 2 t ha-1 however, their further increase with application of 100% RDF+VC @ 2 t ha-1 was found non-significant. Seed inoculation with Rhizobium + PSB significantly increased the number of total and effective root nodules, fresh and dry weight of root nodules and leg haemoglobin content in root nodules. The organic carbon, available nitrogen, phosphorus, potassium, copper, zinc, iron and manganese in soil significantly increased with inoculation of Rhizobium + PSB at the harvest stage of the crop, but EC and pH remain non-significant.

Effect of graded levels of NPK on growth and leaf nutrient content of apple (Malus × domestica) nursery plants

An experiment was conducted during 2017–18 to study the effect of different N, P and K doses on vegetative growth and leaf nutrient content of apple nursery plants of cultivar Starking Delicious and to find out the optimum dose of nutrients for production of healthy planting material for Merton 793 rootstock. The experiment was laid out in a randomized block design comprising 12 combinations of N, P2O5 and K2O {3 levels of N (12, 15 and 18 g/m2 nursery bed), 2 levels of P (3 and 6 g/m2 nursery bed) and 2 levels of K (4.5 and 9 g/m2 nursery bed)}, Jeevamrut and control. The results revealed that maximum linear growth of plant, number of leaves, leaf area, length of main root, total root length, fresh and dry weight of roots, leaf P, Mg and Ca contents were recorded in the plants fertilized with NPK @18:6:4.5 g/m2. However, radial growth of plant, internodal length, fresh and dry weight of shoots, total biomass, leaf N and K were highest in the plants treated with NPK @18:6:9 g/m2 nursery bed. NPK @18:6:4.5 g/m2 nursery bed and NPK @18:6:9 g/m2 nursery bed were found statistically at par with each other with respect to plant growth and leaf nutrients. Thus, nursery bed with 18.0 g N, 6.0 g P and 4.5 g K per m2 was found most suitable for production of quality nursery plants of apple plantlets on Merton 793 clonal rootstock.

Effect of Organic Amendments on the Water Stress Resistance of Corn Varieties during Vegetative Stage in Ultisols

Background: Water stress is one of the most crucial limiting factors in maize production on Ultisols. One solution that could be adopted to solve this problem is applying organic soil amendment. Methods: This study evaluated three varieties of corn: NK-Jumbo, Srikandi Kuning and Lamuru. The water stress treatment consists of 75% field capacity (without water stress) and 37.5% field capacity (water stress treatment). The organic amendment consists of without soil amendment, rice-straw 10 tons ha-1, biochar 10 tons ha-1 and rice straw 5 tons ha-1 + biochar 5 tons ha-1. A factorial, completely randomized design was used in this research. Result: Water stress and organic amendments affect total stomata, leaf curl, leaf area, proline content, shoot and root dry weight, shoot-root ratio and biomass production of corn. Applying organic amendments increases corn’s resistance to water stress, indicated by decreased plant proline content and increased biomass. The proline content of corn by application of organic amendment with rice straw 5 tons ha-1 + biochar 5 tons ha-1 (70.41 µ mol/g) was lower than the proline content of treatment without amendments (93.69 µ mol/g). NK-Jumbo was the most resistant variety to water stress conditions.

Plant Growth-Promoting Rhizobacteria With ACC Deaminase Activity Enhance Maternal Lateral Root and Seedling Growth in Switchgrass.

Switchgrass, a C4 plant with high potential as a bioenergy source, is unsteady in yield under sub-optimal conditions. Bacteria containing 1-aminocyclopropane-1-carboxylate synthase (ACC) deaminase can promote plant growth. We isolated bacteria containing ACC deaminase activity from switchgrass rhizosphere using an orthogonal matrix experimental design with four factors (bacterial liquid concentration, bacterial liquid treatment time, nitrogen content, and NaCl) to quantitatively investigate the effects and pairwise interactions on the seedling growth. Pseudomonas sp. Y1, isolated from the switchgrass cv. Blackwell rhizomes was selected. We optimized the inoculation bacterial concentration, treatment time, NaCl, and nitrogen concentration for the seedling growth. The optimal bacterial concentration, treatment time, NaCl, and nitrogen content was 0.5–1.25 OD at 600 nm, 3 h, 60–125 mM and 158 mg L−1, respectively. Pseudomonas sp. Y1 significantly increased the total root length, root surface, shoot length, and fresh and dry weight through an effective proliferation of the number of first-order lateral roots and root tips. This indicated that Pseudomonas sp. Y1 has a higher potential to be used as a plant growth-promoting rhizobacteria bacteria.

Effects of Different Growth Regulators on Agronomic Characters and Grain Yield of Maize Varieties

In order to screen the sweet corn varieties with strong cadmium tolerance and explore the differences in response to cadmium stress, 12 sweet corn varieties mainly selected in South China were used to study the effects of cadmium treatment. The seedling grew in sand culture until they initiated three leaves in total with two leaves expanded and treated with cadmium ion (Cd 2+ ) solution, and then phenotypic investigation of seedling height, main root length, total root number, fresh weight, dry weight, and SPAD value of the first leaf. The results showed that there were significant differences under cadmium tolerance to those sweet corn varieties with different genetic backgrounds, and most of the eight characters measured had significant correlations between cadmium tolerance indices. A comprehensive index obtained by principal component analysis can effectively evaluate the cadmium tolerance of different varieties of sweet corn, and its contribution rate is 73.42%. Cluster analysis was used to classify 12 sweet corn varieties into sensitive (one variety), intermediate (eight varieties) and tolerant (three varieties). Among them, three varieties including ‘Zhongxiantian 102’, ‘Zhuyutian 1’ and ‘Fotian 10’ had strong cadmium tolerance, which could be further screened for low-cadmium-accumulating varieties to be used in agricultural production. At the same time, by comparing and analyzing the phenotypic variation between two varieties with different response to cadmium stress, it was found that cadmium stress would break the stability of chlorophyll in the leaves of sensitive sweet corn seedlings, affecting photosynthesis, and then reducing the accumulation of biomass and inhibiting growth and development. This study provides reference for further analysis of cadmium-resistant response mechanism of sweet corn.

Effect of Manure Organic Fertilizer and Provibio Biofertilizer on Growth and Yield Mustard (Brassica juncea L

The utilization of goat manure as a planting medium for mustard (Brassica juncea L.) is expected to increase the dose of organic fertilizer and biofertilizer. The study was arranged using a factorial randomized block design (RAK). The first factor is the dose of goat manure and the second factor is the dose of Provibio biofertilizer. The first factor consisted of P0 = no treatment (control), P1 = 5 tons-1, and P2 = 15 tons-1 goat manure. The second factor consisted of D0 = 0 mL (control), D1 = 5 mL, and D2 = 10 mL of Provibio biofertilizer. The data obtained were then analyzed for variance at the 5% level of significance. If there is a real effect, the DMRT test is continued. The results showed that the application dose of manure P2 (15 tons-1) had a higher total plant fresh weight and root dry weight than P0 (control), P1 (5 tons-1). The application of Provibio biofertilizer (without treatment) D0, (5 mL) D1, and (10 mL) D2 has not been able to increase the growth and yield of mustard plants. The application of goat manure and biofertilizer has an independent effect and there is no interaction.

Effects of NPK, Bio-Fertilizers and Manures on Growth of Maize (Zea mays L.) and Soil Nutrients Content in Maiduguri, Nigeria

A pot experiment was carried out at screen house, Faculty of Agriculture University of Maiduguri to compare the effect of NPK, bio-fertilizers and manures applications on growth and nutrient uptake by maize. The experiment consisted of 9 treatments of combined application of NPK at half and full recommended rates for maize, Azotobacter chroococcum, Bacillus megaterium and Pseudomonas fluorescence biofertilizers and cow dung and poultry manures and replicated three times in a Completely Randomized Design (CRD). Result of the treatment having half recommended dose of NPK, biofertilizers and poultry manure recorded the highest plant height at 3, 6 and 9 weeks after planting (95.19 cm, 148.63 cm, 149.63 cm, respectively) the highest total shoot and root fresh and dry weights (74.40 g, 196.93 g, 28.83 g, 46.93 g/plant, respectively). Higher nitrogen, phosphorus and potassium contents of the soil (2.76 g/kg N 0.13 mg/kg P2O5 and 1.41 Cmol/kg K2Osoil) were also recorded with the above treatments.

A growth and biochemistry of ten high yielding genotypes of Pakistani rice (Oryza sativa L.) at maturity under elevated tropospheric ozone

Experimental studies were conducted to estimate the possible damage caused to ten rice (Oryza sativa L.) genotypes of Pakistan by tropospheric ozone. The experimental site is located at 31.4504° N and 73.1350° E, at an altitude of 184 m.a.s level with an average annual rainfall of 784 mm. A suitable and agile method was adopted to assess tolerance and susceptibility in rice genotypes at an early growth stage. Genotype Injury response, growth and biochemical parameters were measured to estimate possible effects of ozone, which was subsequently proclaimed as a criterion for ozone tolerance. Rice genotypes were subjected to ozone concentrations of 70 pbb (Current ambient) and 120 pbb (expected in near future) under a polytunnel. The findings indicated that ozone, an atmospheric pollutant, substantially harmed crop growth and metabolism, as well as inflicted a specific type of foliar injury that caused early leaf senescence. Rice genotype IR-9 followed by Punjab-Basmati and Ksk-434 appeared to be the most susceptible, whereas Basmati-515 followed by Basmati 2000 and super-Basmati were found to be Ozone-tolerant. Plant genotypes grown under elevated ozone showed 13.45% and 11.35% reduction in total root and shoot dry weight, and 25.54% and 6.6% decrease in plant leaf area and plant total length respectively compared to the control group. A significant interaction between treatment × chemical components and growth parameters was also found. The Present study confirms a direct relationship between visual response and growth as well as biochemical parameters. Declared results were statistically analyzed by using analysis of variance at confidence level of p < 0.05.

Irrigation Regime for Protection on Root Intrusion for Subsurface Drip Irrigation

Root intrusion into emitters poses a threat to the service lives of subsurface drip irrigation systems. In an attempt to address this problem, an experiment was conducted on spring wheat grown in soil columns installed in a greenhouse to study the effects of irrigation regimes in protecting against root intrusion into emitters. Spring wheat was planted in soil columns. The specifications of the soil column were 15-cm width, 60-cm length and 100-cm depth. Drip tapes were buried manually in the center of the soil columns at a -40-cm depth. The soil matrix potential at a 20-cm depth immediately over the drip emitters was used to schedule the subsurface drip irrigation regime. Five different irrigation arrangements, with targeted soil matrix potentials of -10, -20, -30, -40 and -50 kPa, were maintained. The soil matrix potential influenced the spring wheat root distribution, emitter flow rate, root intrusion, and spring wheat yield and quality. The total root dry weight increased as the soil matrix potential decreased. Root length density at 35-45-cm increased as the soil matrix potential increased. The decrease in the emitter flow rate increased along with the soil matrix potential. All the treatments had root intrusion, but its severity was correlated with the soil matrix potential. Root intrusion first decreased as the soil matrix potential decreased but then increased as the soil matrix potential continued to decrease. The lowest root intrusion rate (22.22%), as well as the greatest relative yield and relative thousand-grain weight values, were achieved with a soil matrix potential of -40 kPa.