Objective: Citrus (Citrus reticulata) is one of the most important horticultural plant in Iran and weed management throuth ecological methods such as COVER CROP is a proper option in orchard management practices.Methods: The experiment was designed as a split plot on the base of complete randomized block design with four replications in Mazandaran Province, Sari, Voushka county from 2010 to 2012. The main plots were methods of COVER CROP management (desiccated with glyphosate at 0.85 kg ai ha-1, mowed and incorporated with soil with rotivator that were done at the flowering stage), and the subplots were COVER CROP species [sainfoin (Onobrychis viciifolia), winter barely (Hordeum vulgare), triticale (×Triticosecale), sainfoin+barely and sainfoin+triticale] and one control treatment which was without COVER CROP.Results: An important reduction of seedling emergence and total weed dry weight were observed in the plots with COVER CROP dessicated compared with the plots mowed or incorporated with soil. The optimum COVER CROP species for weed control was sainfoin+barely mixes because it had the highest biomass and lowered the amount of light reaching the soil surface and reduced soil temperature fluctuations, resulting in a reduction in weed seedling emergence. In addition weed suppression by it has been attributed in part to allelopathy. In both years there were no differences among treatments in tree yield but to maximize and sustain the output of an orchard, weeds in the tree row have to be controlled efficiently.

Objective: Importance of management of gardens weeds is an issue that unfortunately has less been investigated by weeds researchers of country. One of the most important restrictive agents of cultivated surface and producing CROPs of Citrus orchards are weeds.Methods: To achieve this purpose, a research was performed in plot of Valencia orange trees of citrus fruits of Dezful in 2013. This project was done in the form of randomized complete block with 16 treatments in 3 repetitions. The treatments were mechanical control, Weedmaster herbicide, glyphosate herbicide, vigna unguiculata, vigna radiate, panicum miliaceum L., sorghum bicolor (L) moench, vigna unguiculata+ Weedmaster, vigna radiate+ Weedmaster, panicum miliaceum L.+ Weedmaster, sorghum bicolor (L) moench+ Weedmaster, vigna unguiculata+ glyphosate, vigna radiate+ glyphosate, panicum miliaceum L.+ glyphosate, sorghum bicolor (L) moench+ glyphosate and wetness (uncontrolled).Results: Results showed that sorghum bicolor (L) moench and it’s combining with glyphosate and Weedmaster have the highest height, leaf area, and dry weight, and panicum miliaceum L. and its combining with glyphosate and Weedmaster herbicides have the highest density of COVERing CROPs. Weeds had the least leaf area in treatments of sorghum bicolor (L) moench, sorghum bicolor (L) moench+ Weedmaster and panicum miliaceum L., panicum miliaceum L.+ Weedmaster, and the least productive dry weight of weeds was in treatments of sorghum bicolor (L) moench, sorghum bicolor (L) moench+ Weedmaster and panicum miliaceum L., panicum miliaceum L.+ Weedmaster, and panicum miliaceum L.+ glyphosate. Also, the highest Index CCW belonged to treatments of sorghum bicolor (L) moench+ Weedmaster.

The recent decades emphasis on reducing pesticide use especially herbicide has led to increased interest in alternative weed control methods. The purpose of this study was to evaluate the hilling time and simultaneous interseeding of two COVER CROPs as living mulch to control weeds in potato and to determine the impact of these actions on potato yield. A randomized complete block design as split plot with three replications was used with hilling time (two levels containing 3 and 5 weeks after potato planting) and COVER CROPs (four levels containing barley, persian clover, no-COVER and chemical control) as main and subplot treatments, respectively. The barley COVER CROP in the first hilling time was needed to control using sethoxydim (0.21 Kg ai ha-1).Weed and COVER CROP numbers were recorded three weeks after hilling time and their biomass was measured at harvest time. Generally the hilling time had no effect on weed and COVER CROP numbers but was effective on their biomass so that the average weed biomass in second hilling time was less than its first but the COVER CROP biomass in second hilling time was more than its first because of controlling barley in first hilling time. Barley COVER CROP was superior to Persian clover in weed control and because of slow growth of Persian clover, its weed biomass was as no-COVER CROP treatment. However the potato yields were highest with the chemical control but considering to hilling time and COVER CROP interaction on potato yield, the controlled barley in the first hilling time was to able to provide yields comparable to chemical control. Thus the results suggest that early interseeding of barley as COVER CROP supplemented with a postemergence narrow leaves herbicide may both control weed adequately with less herbicide and provide yields comparable with conventional potato production systems.

In order to study of COVER CROPs effects on weed suppression in sugar beet, an experiment was performed in Iranian Research Institute of Plant Protection (Karaj Station), in 2007. The experiment was arranged as completely Randomized Blocks Design with four replications and seven treatments. The treatments were different COVER CROPs (including: Wheat, barley, triticale and rye) that planted between rows. Chemical weed control, weedy and weed free plots were also used as controls. COVER CROPs were removed by herbicide application (paraquat at 400 g ai ha-1). Phenmedipham+desmedipham+ethofumesat (Betanal Progress A.M, EC 27.4%) was also used in the four-leaf stage of sugar beet. Results indicated that COVER CROP treatments suppressed major weeds (Amaranthus retroflexus L. and Chenopodium album L.) and were similar to recommended chemical control (application of herbicide). In addition, total of weed biomass was decreased in barley, rye and control treatments. The minimum biomass of total weeds belonged to the barley+herbicide treatment. Because of synergism effects, barley+herbicide had maximum of the root and sugar yield (29.83 and 4.47 T ha-1, respectively), that was significant with other treatments. In overall, barely COVER CROP had the most effects on sugar concent. Therefore, sowing winter COVER CROPs between rows for seedbed prepared in autumn (barley, rye, wheat and tritical, respectively) will suppress the dominant weeds and increase the quality and yield of sugar beet.

This experiment was conducted during 2015-2016 in Karaj, Iran to investigate the effect of COVER CROPs on weed control and the use of herbicide on establishment of COVER CROPs as a split-plot arrangement in a randomized complete block design with three replications. Main factors were Festuca ovina, Festuca rubra, Agropyron desertorum, Bromus tomentellus and control (no COVER CROPs, weedy) and sub factor was Bromoxynil + MCPA (Bromicide M. A EC. 40) herbicide in four levels: 0, 300, 450 and 600 gha-1. Based on the findings, B. tomentellus and F. ovina species had the highest COVER CROP dry mater (8 and 5 kg/ m2 respectively). B. tomentellus and F. ovina species had the highest reduction in weed densities (86% and 67%, respectively) and dry weights (81% and 71%respectively) compared to the control. The interaction between COVER CROPs and herbicide on total dry weight of weeds was significant. The most common weeds of the experiment were Alyssum desertorum, Descurainia Sophia and Polygonum aviculare. The mean dry weight reduction of dominant weeds by COVER CROPs compared to control for D. sophia, A. desertorum and P. aviculare were 83%, 71% and 89%, respectively. The highest dry weight loss of dominant weeds was belonged to B. tomentellus and F. ovina treatments. Based on the Shannon Wiener index, the highest reductions of diversity compared to the control (1. 5) were observed for B. tomentellus (0. 6) and F. ovina (0. 73).

In order to investigate the effects of mulch types and different COVER CROPs on relative frequency, density and biomass of weeds and agronomic characteristics and flower and stigma yield of saffron (Crocus sativus L.), an experiment was conducted based on a randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad, during two growing season 2009-2010 and 2010-2011. Treatments were three CROP residues such as sunflower, barley and garlic and six COVER CROP species included barley, matter pea, rye, Persian clover, vetch and arugula and control. Studied characteristics were population, density and biomass of weeds and flower number, fresh weight of flower, stigma yield, leaf emergence rate and flowering rate. Results showed that the effect of treatments was significant (p£0.01) on dry weight and density of weeds. The lowest weed density of narrow-leaf and broad-leaf species were observed in vetch with 0.7 and 0.8 species.m-2 and highest was for control with 11.3 and 16.2 species.m-2, respectively. Also, treatments had significant effects (p£0.01) on leaf emergence rate, flowering rate, flower number, fresh weight of flower and stigma yield of saffron. The maximum flower number and stigma yield were achieved in vetch with 244550.0 flowers.ha-1 and 1010.1 g m-2 and the minimum were for control with 66241.7 flowers ha-1 and 187.5 g m-2, respectively. Applying different CROP residues and COVER CROPs decreased density and dry weight of weeds decreased due to allelopathy trait of them. COVER CROPs increased growth and yield of saffron due to enhancement in nutrient and nitrogen availability as nitrogen fixation and improvement in soil characteristics.

The objective of this study was to evaluate SIMDualKc CROP model and then simulating different scenarios of surface residue COVER. This model estimates evapotranspiration with dual CROP coefficient approach. Therefore, that enables investigation of various mulch effects on evapotranspiration amount. Five management scenarios (organic mulch with densities of 0.2, 0.3, 0.4, 0.5 and 0.6) were simulated with SIMDualKc CROP model during the 2001 and 2002 growing seasons. SIMDualKc model calibration and validation was performed with the results of 2 years data obtained from wheat field experiments located in Aboreihan University College of Tehran University. Then, climate, soil, CROP and irrigation management data were inserted into model. The model estimated soil available water with model efficiency (EF) of 0.902 and calculating the following evaluation criteria: RMSE=1.34 mm, absolute error=0.955 mm and mean relative error=4.67 %.with lack of required data for calibration, using FAO-56 standard CROP and soil evaporative parameters resulted in reasonable accuracy.Various scenarios of CROP residue mulch simulation results showed that with increase of organic mulch density, the ratio of evaporation to evapotranspiration (E/ET) decreased and transpiration rate increased. While ratio of E/ET was 18% w/o CROP residue mulch, by applying organic mulch with density of 0.6 Kg/m2 decreased to 8%.

Introduction: Conservation agriculture is an appropriate strategy for maintaining and improving agricultural resources which increases CROP production and stability and also provides environmental protection. This attitude contributes to the conservation of natural resources (soil, water, and air) and is one of the most effective ways to overcome the drought crisis, water management and compensation of soil organic matter in arid and semi-arid regions. The practice of zero-tillage decreases the mineralization of organic matter and contributes to the sequestration of organic carbon in the soil. Higher amounts of organic matter in the soil improve soil structure and root growth, water infiltration and retention, and cation exchange capacity. In addition, zero-tillage reduces soil compaction and CROP production costs. COVER CROPs are cultivated to protect the soil from erosion and elements loss by leaching or runoff and also improve the soil moisture and temperature. Given that South Khorasan farmers still use traditional methods of cultivation of wheat, and COVER CROPs have no place in their farming systems, the aim of this study was to investigate the effect of COVER CROPs types and tillage systems on yield and yield components of wheat in Birjand region. Materials and Methods: A split plot field experiment was conducted based on randomized complete block design with three replications at the Research Farm of the University of Birjand over the growing season of 2014-2015. The main factor was the type of tillage (no-till, reduced tillage and conventional tillage) and COVER CROP type (chickling pea (Lathyrus sativus), rocket salad (Eruca sativa), triticale (X Triticosecale witmack), barley (Hordeum vulgaris) and control (no COVER CROP)) was considered as sub plots. COVER CROPs were planted on July 2014. Before planting wheat, COVER CROPs were dried through spraying paraquat herbicide using a backpack sprayer at a rate of 3 L ha-1. Then the three tillage treatments were applied, seedbed preparation was carried out and wheat Anfarm-4 (Bam) was planted. At the end of the growing season, yield and yield components of wheat were measured. Results and Discussion: The results indicated that the maximum grain yield, biological yield, and spike. m-2 of wheat were observed with the no-till and reduced tillage treatments. The wheat spike weight significantly increased in the treatment of no-tillage compared with conventional tillage treatment. It seems that increased CROP yield under no-till and reduced till systems might be owing to the enhancement of the soil nutrient status, reduced weed populations, improved physical health of the soil improved soil water status and increased efficiency of nutrient usage in these systems comparing with the conventional tillage systems. The main effect of COVER CROP type showed that incorporating chickling pea and rocket salad resulted in the greatest grain yield, thousand-kernal weight, spike weight, and biological yield of wheat compared to the control (no COVER CROP) and also chickling pea, rocket salad and barley caused the greatest grain. Spike-1 of wheat compared to the control (no COVER CROP). Although the use of total COVER CROPs improved yield and yield components in wheat. Chickling pea superiority in many traits was evident in comparison with other COVER CROPs. This superiority could be due to the fact that this plant belongs to the legume family and legumes release higher amounts of nitrogen during decomposition compared to grass species. Grasses produce large amounts of carbon and are slowly decomposed. Although rocket salad does not belong to the legume family, due to having deep roots, it is able to absorb nutrients from the deep soil layers and provide the main plant with these nutrients after its decay. Conclusions: The results of this study revealed that employment of conservation tillage systems remarkably affected the yield and yield components of wheat, and the greatest positive influence on CROP yield and yield components were observed where chickling pea and rocket salad were sown before wheat cultivation. Thus, COVER CROPs and conservation tillage systems can be used as a promising solution for the development of sustainable agriculture and protecting the health of ecosystems.

The aim of this study, was to evaluate the effect of winter COVER CROP residues on speed of seed potato emergence and percentage of organic carbon, soil specific weight and soil temperature. An experiment was carried out at the Research Farm of Agriculture Faculty, Bu- Ali Sina University, in 2008-2009. The experiment was a randomized complete block design with three replications. Winter COVER CROPs consisted of rye, barley and oilseed rape, each one with common plant density (rye and barley at 190 kg.ha-1 and oilseed rape at 9 kg.ha-1) and triple plant densities (rye and barley 570 kg.ha-1 and oilseed rape, 27 kg.ha-1) and control (without COVER CROP). The results showed that rye and barley with triple plant densities produced higher biomass (1503.5 and 1392.2 g/m2, respectively) than other treatments. Soil physicochemical properties were affected significantly by using COVER CROPs. Rye, barley, and oilseed rape with triple rate and rye with common rape of plant densities produced, the highest organic carbon. Green manure of rye and barley with triple and rye with common rate plant densities, reduced soil specific weights by 17.3, 18 and 18 percent as compared with the control treatment (without COVER CROP planting). Rye and barley with triple plant densities increased average soil temperature by 12 and 11 percent respectively in comparison with control treatment. These treatments increased speed of seed potato emergence by 20 and 12 percent respectively as compared with that of control treatment, respectively. Other treatments showed no significant difference as compared to control. COVER CROP residues increased plants speed of seed potato emergence through improving soil conditions.