Antinociceptive activity of Derris uliginosa

The ethanol extract of leaves of Derris uliginosa given by oral route at dose of 250 and 500 mg/kg produced a significant inhibition on acetic acid-induced writhing in mice.     

Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn

The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. This study was conducted for 2 years (2005 and 2006) to establish optimal irrigation rates and plant population densities for corn (Zea mays L.) in sandy soils using drip irrigation system. The study aimed at achieving high yield and efficient irrigation water use (IWUE) simultaneously. A field experiment was conducted using a randomized complete block split plot design with three drip irrigation rates (I₁: 1.00, I₂: 0.80, and I₃: 0.60 of the estimated evapotranspiration), and three plant population densities (D₁: 48,000, D₂: 71,000 and D₃: 95,000 plants ha⁻¹) as the main plot and split plot, respectively. Irrigation water applied at I₁, I₂ and I₃ were 5955, 4762 and 3572 m³ ha⁻¹, respectively. A 3-day irrigation interval and three-way cross 310 hybrid corn were used. Results indicated that corn yield, yield components, and IWUE increased with increasing irrigation rates and decreasing plant population densities. Significant interaction effects between irrigation rate and plant population density were detected in both seasons for yield, selected yield components, and IWUE. The highest grain yield, yield components, and IWUE were found for I₁D₁, I₁D₂, or I₂D_1, while the lowest were found for I₃D₂ or I₃D₃. Thus, a high irrigation rate with low or medium plant population densities or a medium irrigation rate with a low plant population density are recommended for drip-irrigated corn in sandy soil. Crop production functions with respect to irrigation rates, determined for grain yield and different yield components, enable the results from this study to be extrapolated to similar agro-climatic conditions.     

Optimizing supplemental irrigation: Tradeoffs between profitability and sustainability

Water production functions are used to model yield response to various levels of supplemental irrigation (SI), to assess water productivity coefficients, and to identify optimum irrigation under various input-output price scenarios. The SI production function is taken as the difference between the total water production function (irrigation + rain) and that of rainwater. Theoretical analysis of the unconstrained objective function shows that the seasonal depth of SI to maximize profit occurs when the marginal product of water equals the ratio of unit water cost to unit product sale price. Applying this analysis to wheat in northern Syria, the production functions of SI under different rainfall conditions are developed. Coupled with current and projected water costs and wheat sale prices, the functions are used to develop an easy-to-use chart for determining seasonal irrigation rates to maximize profit under a range of seasonal rainfall amounts.Results show that, for a given seasonal rainfall, there is a critical value for the ratio of irrigation cost to production price beyond which SI becomes less profitable than rainfed production. Higher product prices and lower irrigation costs encourage the use of more water. Policies supporting high wheat prices and low irrigation costs encourage maximizing yields but with low water productivity. The resulting farmer practice threatens the sustainability of water resources. Balancing profitability versus sustainability is a challenge for policy makers. Our analysis can help national and local water authorities and policy makers determine appropriate policies for water valuation and allocation; and assist extension services and farmers in planning irrigation infrastructure and farm water management.     

Dynamics of macronutrients in olive leaves

The study aims to track the dynamics of the olive leaf nitrogen (N), phosphorus (P) and potassium (K) for five olive varieties under drip irrigation in farmer's fields in central Morocco. Leaf sampling was done every month from May 2014 to April 2015. Leaf macronutrients contents showed variation over time. Olive leaves have maintained the same N content throughout the study period indicating a continuing olive uptake of nitrogen. Higher leaf P absorption was observed during flowering and fruit magnification periods indicating the important P needs of olive during these periods. Olive leaf K levels were higher from September to December indicating the high K needs of olive. No variety effect was revealed on the leaf N, P and K contents. Very highly significant differences were found between the leaf N and K levels measured at different sampling periods. The leaf P concentration was statistically equal in all measuring periods.     

Assessment of Biodegradation of Oleandrin during Co-composting of Nerium oleander L. Wastes

ABSTRACT

Variations in the levels of the highly toxic oleandrin molecules were studied during composting of Nerium oleander L. waste mixed with clippings of the grass Pennisetum clandistenum L. The thermophilic phase is characterized by a rise in temperature, which reached 70°C. After 150 days of co-composting, the C/N ratio was 11, the pH was 8, the NO₃^?/NH₄⁺ ratio was greater than 1 and overall decomposition reached 70%. During the successive stages of co-composting, oleandrin concentrations were monitored by HPLC. The relative abundance of oleadrin was 26.84% at T0 with 10% abatement during the first month and 90% after two months (stabilization phase), reaching 100%, i.e., total removal after 90 days of co-composting (maturation phase). The biodegradation of the toxic substance was largely attributed to the activity of actinomycetes and fungi. The germination index of lettuce and watercress seeds exceeded 50% after 90 days and reached 95% after 150 days, confirming that the final compost was mature, stable, and free from phytotoxicity in spite of the highly poisonous starting material.     

Assessment of genetic divergence in salt tolerance of soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L.) genotypes

A large number of soybean (Glycine max L.) genotypes of diverse growth habit and adaptive characters were used in the experiment. Soil salinity-induced changes in nine morpho-physiological characters of 30-day-old seedlings of 170 soybean genotypes were compared in the study. The first and second principal components (PC) of principal component analysis (PCA) results accounted for 97 and 2.5%, respectively, of the total variations of soybean genotypes. The variation for the first PC was composed mainly of relative total dry weight (DW), relative shoot dry weight, as well as petiole dry weight. There were four clusters distinguished in the cluster analysis. The genotypes in cluster IV performed better in respect to relative total dry weight and relative shoot dry weight and hence having salt tolerance. The genotypes clusters III performed very poorly and those of clusters II and I were moderate to poor. D2 analysis indicated that the clusters differed significantly from each other. Discriminant function analysis (DFA) again asserts strongly that more than 92% of the genotypes were correctly assigned to clusters. Both PCA and DFA confirmed that the relative total DW followed by shoot and petiole DW were the major discriminatory variables, and the root DW were the secondary important variables to distinguish genotypes into groups. In this study, multivariate analyses were used in identifying the soybean genotypes of desirable traits for salt tolerance.     

The Cytological Status of Plants Regenerated from Shoot-Meristem Culture of Pisum sativum L

The cytological status of plantlets regenerated from shoot apical meristems of Pisum sativum was investigated. Chromosome counts in root apices of in vitro regenerated plants showed a preponderance of diploid cells. Moreover, the karyotypes of root-tips from plants derived from culture and from normal plants were basically the same. Topics such as the treatment of chromosomal armlength data, simple statistical comparison of samples derived from normal and regenerated plants are discussed.     

Comparison of leaf and pod disease reactions of beans (Phaseolus vulgaris L.) inoculated by different methods with strains of Xanthomonas campestris pv. Phaseoli (Smith) dye

Summary Common blight disease in beans (Phaseolus vulgaris), caused by the bacterium Xanthomonas campestris pv. phaseoli, reduces crop yield and seed quality. Information is needed on the variation of leaves and pods disease reaction to strains of the bacterium after different inoculation methods. Phaseolus vulgaris cultivars Red Kidney Charlevoix, GN Harris, GN 1140, and GN Emerson were inoculated with three different strains of Xanthomonas campestris pv. phaseoli at two inoculum concentrations (10⁸ and 10⁶ bacterial cells/ml) using water soaking, multiple needle, and razor blade inoculation on leaves, and razor blade scratch, dissecting needle, and razor blade cut inoculation on pods. Differential cultivar disease reactions of leaves, pods, or both to the bacterial strains were observed in some cases. Significant interactions among cultivars, inoculation methods, strains, and inoculum concentrations (leaves) were found. A rapid leaf chlorosis developed 6 to 7 days after inoculation. Strains of bacteria did not show specificity in inducing this reaction, but rapid leaf chlorosis was associated with high inoculum concentration and with the water soaking and multiple needle methods. Another experiment was conducted to count the number of living bacterial cells deposited in the leaf tissue after inoculation by different methods. The number of bacteria deposited by water soaking or multiple needle was higher than that deposited by razor blade.Published as Paper No. 8584, Journal Series, Nebraska Agricultural Experiment Station. Research was conducted under Project No. 20–36.     

Labor- und Freilandversuche zur Bekämpfung von vier Blattlausarten mit zwei synthetischen Juvenilhormon-Analogen

Laboratory and field trials with two synthetic Juvenil Hormone Analogues on four Aphid species Two juvenile hormone analogues (JHA) were applied in laboratory in three different concentrations to four aphid species. Mortality-concentrations and mortality-time for the lowest concentration were plotted on logprobit paper and the slope calculated from the eye fitted lines. The results indicated the feasibility of probit analysis for concentration-mortality or time mortality responses. However in one of the aphid species i. e.Aphis gossypii, there was a lack of linearity in the relationship, this species proved to be tolerant to JHA in field trials. Both JHA supressed progeny production, the supression was found to be selective to different species. In field trials both JHA brought about appreciable reductions in the populations with the exception ofAphis gossypii. The colour ofH. arundinis was found to differ in adults insuing from treated nymphs, otherwise no remarkable morphonogenic changes were observed.