Antagonistic potential of Trichoderma harzianum and Azadirachta indica against Fusarium oxysporum f. sp. capsici for the management of chilli wilt

Journal of Plant Diseases and Protection - Fusarium oxysporum f. sp. capsici (Foc) induces wilt disease in chilli and affects its yield. Implementing microorganisms and plant extracts for plant...     

Salt-induced perturbation in growth,physiological attributes,activities of antioxidant enzymes and organic solutes in mungbean (Vigna radiata L.) cultivars differing in salinity tolerance

A pot experiment was conducted to appraise the inhibitory effects of salt stress on biochemical attributes in the three mungbean cultivars (NCM-209, NCM-89 and NM-92). Salt stress caused a significant decrease in plant height, shoot relative water contents, photosynthetic pigments, endogenous levels of K⁺ and K⁺/Na⁺ ratios and increase in cellular levels of H₂O₂, MDA, Na⁺ and Cl^?. However, cv. NCM-209 was found to be tolerant in terms of lower salt-induced decline in K⁺, K⁺/Na⁺ ratio and photosynthetic pigments. The endogenous levels of H₂O₂ and MDA were also lower in cv. NCM-209. Salt stress markedly also affected different yield attributes in all mungbean cultivars. Again cultivar NCM-209 exhibited less inhibitory effects of salt stress on different growth attributes. Salt stress resulted in a marked increase in the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase) in mungbean cultivars. Activity of peroxidase was maximal in cv. NCM-209 and catalase activity was maximal in cv. NCM-89, whereas cvs. NCM-89 and NM-92 showed higher activities of superoxide dismutase. Similarly activity of ascorbate peroxidase was higher in cv. NM-92. It could be inferred from data of antioxidant enzymes that mungbean cultivars cannot be categorized as salt tolerant or sensitive on the basis of a single antioxidant enzyme.     

Effect of Varying Nitrogen Regimes on Growth,Seed Yield,and Nutrient Accumulation in Isabgol

A greenhouse experiment was conducted to determine the optimum dose of nitrogen (N) fertilizer for attaining maximum yield of isabgol (Plantago ovata Forsk.). Sixty three-day-old plants were subjected to varying levels of N (0, 30, 60, and 90 kg N/ha) until seed harvesting. Maximum growth and seed yield occurred at 60 kg N/ha, whereas 90 kg/ha was inhibitory to isabgol growth. The growth and seed yield recorded at 30 or 60 kg N/ha did not differ much, and in view of the high cost to be incurred from applying 60 kg N/ha and the relatively low yield achieved at this level, 30 kg N/ha would be a much more suitable level for isabgol. Accumulation of N, potassium (K), and phosphorus (P) in shoots or roots of isabgol increased consistently under increasing levels of N, but this pattern of increase in the levels of three nutrients in plant tissues was negatively associated with the growth of the crop, particularly at the supra-optimal N level (90 kg N/ha).     

A Study on Seasonal Variability of Trace Elemental Status of Forages for Grazing Ruminants

An investigation was conducted to determine the trace- mineral concentrations of forages in relation to requirements of ruminants grazing in natural pastures in the province of Punjab, Pakistan during two different seasons. Animals were closely followed during grazing and forages corresponding to those consumed by the animals were taken and analyzed for copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and cobalt (Co) concentrations. The data on the trace- mineral concentrations showed that most of these minerals varied greatly as a function of seasons and sampling periods. The forage Cu, Fe, and Zn concentrations were affected by seasonal changes but no influence of season was observed on the concentrations of forage Mn and Co concentration. Forage Zn and Co, during both seasons and at some sampling intervals, and forage Mn during summer were at marginal deficient levels, and in contrast, all other forage trace-minerals were within the required range for ruminants during both seasons. Based on these results, the supplementation of Zn, Co, and Mn would seem most important to support optimum livestock productivity.     

Inducing Salt Tolerance in Wheat by Exogenously Applied Ascorbic Acid through Different Modes

ABSTRACT

In order to assess whether exogenous application of ascorbic acid (AsA) through different ways could alleviate the adverse effects of salt-induced adverse effects on two wheat cultivars differing in salinity tolerance, plants of a salt tolerant (‘S-24’) and a moderately salt sensitive (‘MH-97’) cultivar were grown at 0 or 120 mM sodium chloride (NaCl). Ascorbic acid (100 mg L^?1) was applied through the rooting medium, or as seed soaking or as foliar spray to non-stressed and salt stressed plants of wheat. Salt stress-induced reduction in growth was ameliorated by exogenous application of ascorbic acid through different ways. However, root applied AsA caused more growth enhancement under saline conditions. Leaf ascorbic acid, catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities were also maximal in salt stressed plants of both cultivars treated with AsA through the rooting medium. Furthermore, leaf ascorbic acid, CAT, POD, and SOD activities were higher in salt stressed plants of ‘S-24’ than those of ‘MH-97’. Root applied AsA caused more enhancements in photosynthetic rate. Root applied AsA caused more reduction in leaf sodium (Na⁺) compared with AsA applied as a seed soaking or foliar spray. Overall, AsA-induced growth improvement in these two wheat cultivars under saline conditions was cultivar specific and seemed to be associated with higher endogenous AsA, which triggered the antioxidant system and enhanced photosynthetic capacity.     

Potassium Substitution by Sodium in Root Medium Influencing Growth Behavior and Potassium Efficiency in Cotton Genotypes

ABSTRACT

Potassium (K) deficiency affects cotton (Gossypium hirsutum L.) growth. Sodium (Na) can substitute K for some non-specific functions in plants. Four cotton genotypes were evaluated for their growth rates and K use efficiency grown at various K:Na. The cotton genotypes and treatments had significant (p < 0.01) effect on biomass production, growth rate related parameters, K use efficiency, and K: Na ratio. Maximum total dry matter (2.57 g plant^-1) was accumulated by ‘NIBGE-2’ and minimum (1.91 g plant^?1) was by ‘FH-1000’. Maximum K:Na ratio in shoot was obtained by ‘MNH-786’ and minimum was by ‘NIBGE-2’when 1/3rd K was replaced with Na. Genotypes and various treatments significantly (p < 0.05) influenced specific utilization rate (SUR) and K transport rate (KTR). There was a significant relationship (R² = 0.84, n = 60) between shoot dry matter and K: Na ratio in shoot. Overall, the growth was better when K and Na were added in ratio of 3:1.     

WHEAT GENOTYPES DIFFERED SIGNIFICANTLY IN THEIR RESPONSE TO SILICON NUTRITION UNDER SALINITY STRESS

We studied the growth and ionic composition of five wheat genotypes (Inqlab-91, Uqab 2002, SARC-1, SARC-3, and SARC-5) grown under salinity stress to applied silicon. Plants were grown with three levels of salinity [0, 60, and 120 mM sodium chloride (NaCl)] in the presence of 0, 2, and 4 mM Si in nutrient solution for 40 days. Salinity stress significantly decreased shoot and root biomass in plants with varying degrees. Genotype SARC-3 exhibited higher salt tolerance than other genotypes. Silicon (Si) application significantly (P < 0.05) increased plant biomass at both control as well as under saline conditions. Genotypes differed significantly for their response to applied Si in terms of biomass production. Silicon application significantly (P < 0.01) increased potassium (K⁺) concentration in shoots. Enhanced salinity tolerance in wheat by Si application was attributed to increased K⁺ uptake thereby increasing K⁺/sodium (Na⁺) ratio and lower Na⁺ translocation towards shoot.     

Ion distribution in leaves of varying age in salt‐tolerant lines of alfalfa under salt stress

Two lines of alfalfa (Medicago sativa L.), a salt‐tolerant AZ‐Germ Salt II and a salt‐sensitive Mesa Sirsa, were grown for three weeks in solution culture containing 0 or 100 mol/m³ sodium chloride (NaCl) in half‐strength Hoagland nutrient solution. Distribution of cations and chloride (Cl) in the leaves of varying ages was determined. The older leaves (age‐dependent) of both lines contained more sodium (Na) in the laminae and petioles than the younger leaves at the salt treatment, whereas the reverse was true for potassium (K) in the laminae. Age‐dependent Cl distribution was only found in the laminae of AZ‐Germ Salt II. Distribution of calcium (Ca) in the lamina and petioles was strongly age‐dependent in both lines, but such a pattern was not found for magnesium (Mg) concentrations. AZ‐Germ Salt II accumulated considerably higher concen‐ trations of Na and Cl in the laminae compared with Mesa Sirsa. The lower Na and Cl concentrations in the laminae of Mesa Sirsa were due to relatively higher accumulation of these ions in the stems. It is concluded that distribution of Na, Cl, and Ca in the leaf laminae is age dependent. Salt tolerance in alfalfa is related to inclusion of Na and Cl in the leaf laminae.     

Distribution of cations in leaves of salt‐tolerant and salt‐sensitive lines of sunflower under saline conditions

Two lines of sunflower (Helianthrus annuus L.), a salt‐tolerant Euroflor and a salt‐sensitive SMH‐24, were grown for three weeks in sand culture containing 0 or 150 mol/m³ NaCl in full strength Hoagland nutrient solution. Distribution of cations in the leaves of varying ages was determined. The older leaves of SMH‐24 contained more sodium (Na) in the laminae than the younger leaves at the salt treatment, whereas laminae of leaves of varying ages of Euroflor maintained Na concentration almost uniform. Distribution of potassium (K), calcium (Ca), and magnesium (Mg) in the laminae was strongly age‐dependent in both lines, i.e., the older leaves contained greater concentrations of these cations than did the younger leaves. The lines did not differ in concentrations of the three cations. The older leaves of SMH‐24 had significantly lower K/Na ratios than those of Euroflor, but the lines did not differ in lamina Ca/Na ratios. It is concluded that distribution of K, Ca, and Mg in the leaf laminae is age‐dependent. Salt‐tolerance in sunflower is related to exclusion of Na in the leaf laminae and to maintenance of almost uniform concentrations of this ion in leaves of all ages.     

Veneer strand flanged I-beam with medium density fiberboard or particleboard as web material I: the forming method and fundamental properties

I-beams flanged with veneer strands with medium density fiberboard (MDF) or particleboard as web material were produced by hot pressing. The forming and pressing method used a special metallic mould that allowed flanges to be formed and bonded to the web at the same time. Many I-beams were able to be produced in a single hot pressing cycle and this method allows the utilization of residues and wastes from wood and wood-composite industries. The forming and pressing method was found to be technically suitable for the production of such I-beams. The fundamental properties of the specimens produced were assessed and the results indicated that the I-beams had promising mechanical properties; for example, the modulus of rupture ranged from 40 to 56MPa depending on the flange density. The bond quality between the web and flange was found to have a critical effect on the strength of the entire I-beam. The I-beams were found to have relatively high bond strengths between the web and flange, ranging from 3.3 to 5.0MPa in the parallel direction. The dimensional stability of the I-beams was found to be excellent in the thickness direction of the beam, but not in the compression (width) direction.Part of this paper was presented at the 53rd Annual Meeting of the Japan Wood Research Society in Fukuoka, March 2003