Effects of desert dust on yield and yield components of cowpea (Vigna unguiculata L.)

In order to study the effects of desert dust on yield and yield components of cowpea, two field experiments were conducted in the factorial layout based on randomized complete block design with three replicates in Dezful and Mashhad, Iran in 2015. The experimental treatments were combinations of desert dust in three levels (0, 500 and 1500 µg m^?3), numbers of desert dust application (once, twice and thrice) and two types of desert dust. The desert-dust particles were collected during dust storms occurred in Dezful and Zabol, which are the main sources of dust in Iran. The results showed that the biological yield and the grain yield were significantly decreased in both studied sites (Dezful and Mashhad) when the plants exposed to 500 µg m^?3 desert dust treatment compared to normal conditions. Total soluble sugar and proline contents in plant leaf tissues increased significantly when they affected by 1500 µg m^?3 of desert dust, while the plant height was significantly decreased by increasing the desert-dust concentrations at both sites. Biological yield, grain yield, and 100-seed weight were also significantly affected by the desert dust. Overall, the desert dust has adverse effects on yield of cowpea.     

Silicon-nanoparticle Mediated Changes in Seed Germination and Vigor Index of Marigold (Calendula Officinalis L.) Compared to Silicate Under PEG-induced Drought Stress

Gesunde Pflanzen - The current study explores the potential impact of seed priming with silicon nanoparticles (SiNPs, 0, 100, 200, 500?mg/L) and silicate (Si, 0, 1, 1.5, 2?mg/L) under...     

Effect of nutrient management and straw mulching on crop yield,uptake and soil fertility in rapeseed (Brassica campestris)–greengram (Vigna radiata)–rice (Oryza sativa) cropping system under Gangetic plains of India

An experiment was conducted at Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India during 2001–2003 to study the effect of levels of fertility and straw mulch on a rapeseed (Brassica campestris var yellow sarson)–greengram (Vigna radiata)–rice (Oryza sativa) cropping system under a rainfed upland ecosystem. The experiment was laid out in a split-plot design having 14 treatment combinations of organic and inorganic nutrients along with straw mulch in three replicates. The results revealed that conjunctive use of organic and inorganic nutrients as well as paddy straw mulch resulted higher yield in both rapeseed and greengram, and the residual effects of different levels of fertilization and mulching also gave rise to higher grain yield in the succeeding rice crop. The uptake of nutrients, by the cropping system as a whole, to the tune of 204.29 and 183.00 kg ha^?1 of N, 72.84 and 74.07 kg ha^?1 of P and 179.95 and 175.41 kg ha^?1 of K took place, with the treatment receiving 10 t ha^?1 of farmyard manure (FYM) applied (to rapeseed) along with 50% recommended dose (RD) of NPK to all the crops in the sequence in two consecutive years, respectively. The same treatment resulted in a higher percentage of porosity vis-à-vis lower bulk density. Soil physico-chemical properties were superior in mulch-treated plots compared with no mulch treatment. Application of organic and inorganic nutrients along with proper moisture conservation practices can enhance the yields maintaining a good soil health.     

Effect of continuous and intermittent irrigation methods on rice (cv. Koohrang) yield

This study was carried out to evaluate the impact of permanent and intermittent irrigation on the yield of rice (cv. Koohrang) in Lordegan rice-growing areas in Chaharmahal and Bakhtiari Province (Iran). The experiment was set up in a randomized complete block design with four treatments and four replications during 2003 and 2004. Irrigation treatments were: I1, continuous irrigation with a 5-cm water head every day; I2, alternative irrigation with a 5-cm water head every 2 days; I3, alternative irrigation with a 5-cm water head every 4 days; and I4, alternative irrigation with a 5 cm water head every 6 days. Results showed that the paddy yield was highest under treatment I2 (5655.6 kg ha^?1) and lowest under treatment I4 (3421.3 kg ha^?1). The highest rate of water use was obtained in I1 with 17 687.5 m³ ha^?1 and the lowest in I4 with 9325 m³ ha^?1. Paddy yield, plant height, panicle length and 1000-seed weight did not show a significant difference at the 5% level among I1, I2 and I3, but differed significantly to I4. Thus irrigation treatment I3 is appropriate for paddy irrigation in the Lordegan region with 10 645 m³ ha^?1 water use and 5483.7 kg ha^?1 paddy yield.     

Seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle in Isfahan Province, Iran

Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis (EBL) is an exogenous C-type oncovirus in the Retroviridae family. It causes significant economic losses associated with the costs of control and eradication programs due to carcass condemnation at slaughter and restrictions of export of cattle and semen to importing countries. The main objective of this research was to determine the seroprevalence of BLV infection in cattle herds in central region of Iran (Isfahan province) using a commercial enzyme-linked immunosorbent assay (ELISA) to detect serum antibodies against BLV. Samples of blood serum were collected from 403 female dairy cattle (Holstein-Friesian) from 21 livestock farms and 303 animals (81.9%) were BLV seropositive. A significant association was found between age as a potential risk factor and BVL seroprevalence with animals ≥ 4 years (86.6%) having a significantly (χ(2) = 35.6, p < 0.001) higher seroprevalence compared to those < 4 years (54.2%). We found no significant statistical association between seroprevalence and pregnancy, lactation status and farming systems as potential risk factors in this study (p > 0.1). It is concluded that BLV infection is a very common problem in the study area. Hence, control measures should be instituted to combat the disease and further studies are required to investigate the impact of this disease on dairy production in the country.     

Which Social-Psychological Models Explain Rangers’ Participation in Rangeland Management Cooperatives? An Application of Path Analysis

The highly centralized management of rangelands in northwest Iran has caused their degradation. Rangeland Management Cooperatives (RMCs) have been taken into account by the Iranian researchers and practitioners as the best mode of managing and tackling these resources. In this regard, stakeholders’ participation (i.e., the rangers) in such institutions is a substantial issue because without their close collaboration, any management scheme is likely to fail or succeed partially. Therefore, this study investigates the rangers’ participation in RMCs using the theory-triangulation method. We developed the main research question: how the explanatory variables, extracted from the social-psychological models, influence rangers’ participation in RMCs. A sample of 200 rangers participated in the survey method, of which we received 179 completed self-reported questionnaires. The reliability of the questionnaire was calculated using the Confirmatory Factor Analysis and Kuder-Richardson 21, the metrics that measure the consistency of items in indicator variables with the interval and binary scales, respectively. The results of path analysis unveil that job satisfaction and progressivism have a direct effect on participation, and the improved economic conditions of industries developed by the RMCs, good intrarelation, fatalism, progressivism, optimism, and cost-benefit indirectly influence participation via job satisfaction. On the basis of these results, it is concluded that to increase rangers’ participation in RMCs, which is a key factor in preventing the degradation of rangelands, RMCs’ officials need to improve the local industries benefiting from the rangelands and upgrade intracommunication skills via training. It is also suggested that all rangers, even those with fatalistic beliefs, need to be included in RMCs’ participatory activities. Finally, it is needed to assess progressivist rangers’ needs, promote optimism, and visualize the economic, social, and conservation benefits of the participation in RMCs.     

Oviposition preference and larval performance of Aeolesthes sarta (Coleoptera: Cerambycidae) in six hardwood tree species

Sarta longhorned beetle (SLB), Aeolesthes sarta Solsky, is an economically important pest of fruit and shade trees in central and east Asia. Choice, no-choice, and larval insertion experiments were conducted to determine SLB oviposition preference and larval host suitability on six hardwood tree species including Ulmus carpinifolia Borkh., Ulmus carpinifolia var. umbraculifera Rehd., Platanus orientalis L., Populus alba L., Salix alba L., and Fraxinus rotundifolia Miller subsp. persica (Boiss.), under laboratory conditions. In the choice and no-choice experiments, significantly greater numbers of eggs and living larvae, and greater mass of living larvae were found on U. carpinifolia and U. carpinifolia var. umbraculifera compared to those on the other tree species. In the choice experiment, oviposition did not occur on F. rotundifolia subsp. persica. There were a few eggs on P. alba but no living larvae. The mean mass of living larvae was lowest on P. orientalis. In addition, in the no-choice experiment significantly fewer numbers and mass of living larvae were found in P. alba and F. rotundifolia subsp. persica. In the larval insertion experiment, more larvae survived on U. carpinifolia and U. carpinifolia var. umbraculifera compared to the other trees. Larvae recovered from U. carpinifolia and U. carpinifolia var. umbraculifera weighed significantly more than larvae from the other trees. These results suggest that U. carpinifolia and U. carpinifolia var. umbraculifera are the most preferred and suitable hosts for SLB adults and larvae. Salix alba is an acceptable host for adult oviposition and a potentially suitable host for larval development. Platanus orientalis and P. alba are less suitable, and F. rotundifolia subsp. persica appeared to be unsuitable as a host for SLB.     

A basal area increment model for individual trees in mixed continuous cover forests in Iranian Caspian forests

The aim of this study was to develop and test a new basal area growth model in mixed species continuous cover forests in northern Iran.Weanalyzed 421 core samples from 6 main species in the forest area to develop our growth model.In each plot,we measured variables such as total tree height(m),diameter at breast height(DBH)(cm)and basal area of larger trees as cumulative basal areas of trees(GCUM)ofDBH[5 cm.The empirical data were analyzed using regression analysis.There was a statistically significant nonlinear function between the annual basal area increment,as the dependent variable,and the basal area of the individual trees and competition as explanatory variables.Reference area from the largest trees,was circular plot with area of 0.1 ha.GCUM was estimated for trees of DBH>5 cm.Furthermore,we investigated the dependencies of diameter growth of different species on stand density at different levels of competition,and diameter development of individual trees through time.The results indicate that competition caused by larger neighborhood trees has a negative effect on growth.In addition,the maximum diameter increment is affected by competition level.Therefore,the maximum diameter increment of species occurs when the trees are about 35–40 cm in dense-forest(40 to 0 m^2 per ha)and when the trees are about 60 to 70 cm in very dense forest(60 to 0 m^2 per ha)which is more likely to Caspian natural forests with high level density due to uneven-aged composition of stands.