In order to assess AND compare the potential FORAGE production of CRIMSONCLOVER with other CLOVER species in different planting dates, an experiment was carried out in split plot arranged in a rANDomized complete block design with 12 treatments in four replications in Karaj during 2003-2005. In this study pkanting dates were considerd as main plot in four levels (d1: 23 Aug., d2: 6 Sep., d3: 23 Sep. AND d4: 7 Oct.) AND CLOVER cultivars as subplot in three levels (v1: CRIMSON CLOVER, v2: Berseem CLOVER AND v3: Persian CLOVER). The results of combined analysis of the experiment demonstrated that effects of year, planting date, year × planting date, species, year × species, planting date × species AND year × planting date × species (except dry matter YIELD) were significantly different for fresh AND dry matter YIELD. Mean comparison of planting dates AND CLOVERspecies showed that planting date d1 with 70.20 tha-1 fresh YIELD, 13.23 tha-1 dry matter YIELD, AND Persian CLOVER with 83.40 tha-1 fresh YIELDs (the same group with Berseem CLOVER), 15.23 tha-1 dry matter YIELDs were the best treatments. Meanwhile, mean comparison of the interaction of planting date × species showed that d3v3 with 90.21 AND 18.82 tha-1 fresh AND dry matters was the best treatment.

To assess agronomic AND economical aspects of mixed cropping of alfalfa AND annual FORAGE crops a filed experiment was carried out using split plot arrangement in rANDomized complete block design with three replications, in research field of Seed AND Plant Improvement Institute, Karaj, Iran in 2007 AND 2008 growing seasons. Experimental treatments included mixed ratio of alfalfa seed with other FORAGE crops (Pesian CLOVER, CRIMSON CLOVER AND FORAGE rape). These ratios were 100:0, 75:25, 50:50 AND 0:100 (alfalfa: FORAGE crop). For agronomic traits, fresh AND dry FORAGE YIELD, analysis of variance AND mean comparison were preformed. For economical assessment partial budgeting AND breakeven analysis were used. Results showed that there were significant differences among mixed cropping treatments for fresh AND dry FORAGE YIELD. Substitution of 75% Alfalfa + 25% CRIMSON CLOVER by other mixed cropping treatment was not profitable. Application of 75% Alfalfa + 25% CRIMSON CLOVER had 14.94 million Iranian rials per hectare net profil which was greater than the other treatments. Breakeven point for selected treatment (75% Alfalfa + 25% CRIMSON CLOVER) in comparison with sole crop of alfalfa (Second priority treatment) AND 75% Alfalfa + 25% FORAGE rape (Third priority treatment) were estimated 22.8 AND 24.8 million Iranian Rials, respectively. Breakeven points of gross income of selected (75% Alfalfa + 25% CRIMSON CLOVER) in comparison to sole crop of Alfalfa AND 75% Alfalfa + 25% FORAGE rape were 34.6 AND 32.7 million Iranian Rials, respectively.

To assess required growing degree days (GDD) for phenological stages of four CLOVER species in different planting dates a field experiment was conducted in 2010-11 AND 2011-12 cropping seasons in Seed AND Plant Improvement Institute in Karaj, Iran. Three planting dates (14 September, 28 September AND 13 October) AND six CLOVER varieties were assigned to main plots AND sub-plots, respectively, as split plot arrangement in rANDomized complete blocks design with four replications. Results showed that delaying planting date decreased the required growing degree days for FORAGE production in CLOVER species by 8.2% AND 14.7% in second AND third planting dates, respectively. Average growing degree days showed that for three cutting of FORAGE in Karaj region about 2437 GDDs are required. Result also revealed that the greatest GDDs (612.7) was required from emergence to vegetative growth stage AND the least GDDs (82.1) belonged to from emergence to the appearance of first simple leaf stage. Comparison of CLOVER species showed that red CLOVER with 2994.9 GDDs AND CRIMSON CLOVER with 1107.7 GDDs had the greatest AND least thermal requirements for FORAGE production, respectively.

This experiment was carried out to compare the potential for FORAGE production is 12 CLOVER cultivars in Karaj in three cropping seasons. The experimental design was RCBD with three replications. The results showed  that the effects of years, cultivars, cuttings AND the interaction of cutting * cultivars were significant for dry matter at 1% probability level. The comparison among different cuttings showed that the highest dry matter were obtained from the first cutting in 1999 AND 2001  (2.14 AND 2.85 t/ha) respectively, AND from the second cutting in 2000 (2.68 t/ha ). Generally the first cutting had higher dry matter than other cuttings. Mean comparison for dry matter production, over season, of persian CLOVER cultivars showed that the cultivar Aleshtar with  8.48 t/ha in  1999 AND the cultivar Doochin-e-kordestan with 9.31 t/ha in 2001, AND the cultivar Aleshtar with 8.53 t/ha had the highest dry matter among all cultivers. Significant difference was also observed in morphological characters among CLOVER cultivars at 1% probability level. Overall, results showed that the Berseem CLOVER for the plant height, the persian CLOVER for the internode length AND sub-branches number, AND the Red CLOVER for the leaf/stem ratio were superior. Regarding potential for FORAGE production, Aleshtar, Simipilyosum AND Tolidy-e-karaj cultivars could be recomended for Karaj region.

To assess the FORAGE YIELD potential of some red CLOVER cultivars, an experiment (RCBD) was carried out with six treatments AND four replications in Karaj for three years (2003–2005). The results showed that the effects of year, cultivars AND year cultivars were significant. Redqueen cultivar with 78.32 th-1 fresh YIELD AND 15.25 th-1 dry matter YIELD producted the highest YIELD. FORAGE YIELD of red CLOVER cultivars showed a decrease pattern from the first to the third year. The higest FORAGE YIELD was produced in the first year AND the lowest in the third year. Plant height AND regrowth rate had different reactions in different cuttings. Kuluobara cultivars with 60.02 cm plant height AND 98.86 gm-2 regrowth rate were the best cultivars. All red CLOVER cultivars were susceptible or highly susceptible to Powderly midew except Kuluobara that was moderately resistant. Finally, based on the results AND findings of the present study, as the FORAGE YIELD of two cultivar Redqueen AND Kuluobara was not significantly different, these two cultivars can be recommended for cultivation in Karaj region.

In order to assess AND compare the quantitative FORAGE YIELD of berseem CLOVER (Trifolium alexANDrinum), six berseem CLOVER cultivars (Tolidi-e-Karaj, Selected line, Mesri, Sacromont, Letto AND Zemestangozar, a cold tolerant cultivar) were used. A field experiment was carried out at SPII experimental station in Karaj in 1998-1999 growing seasons. The design of the experiment was rANDomized complete block (RCBD) with four replications AND six treatments. The results of the experiment showed that there were not significant differences among cultivars in dry matter YIELD. The results of combined analysis of variance showed significant differences between years AND cultivars based on dry matter YIELD at the 1% level. Among the cultivars, Tolidi-e-Karaj AND Letto with 7.16 AND 7.15 tha-1 dry matter YIELD, respectively, showed superiority (7% - 8%). Based on the comparison of means AND other morphological characters, Tolidi-e-Karaj cultivar could be recommended as suitable cultivar for Karaj environmental conditions.

Study AND comparison of potential FORAGE YIELD AND morphological traits of imported Berseem cultivars with current CLOVER cultivars, will increase diversity among CLOVER cultivars AND increase FORAGE production in the country. This experiment was conducted in a rANDomized complete block design with thirteen cultivars AND four replications in Karaj. The two-year combined analysis of variance showed that the effects of year AND cultivars were significant for the fresh AND dry matter FORAGE YIELD AND morphological traits at 1% probability level. This implies to genetic variation among cultivars AND differential effect of year on FORAGE production AND morphological characteristics of Berseem CLOVER cultivars. Mean comparisons showed that Polycross cultivar with 70.25 AND 16.65 tha-1 AND Isoleh-e-Mesri cultivar with 48.84 AND 10.70 tha-1 had the highest AND lowest fresh AND dry matter YIELD, respectively. The effects of cultivar AND year on some morphological characteristics such as plant height was significant AND there was a positive AND significant correlation between these traits AND FORAGE YIELD. The imported cultivars Wiener, Elite 2 AND Selected line, AND the local cultivars Tolidi-e-Dezful, Polycross Karaj AND Sacromont MazANDaran with 68-69 tha-1 fresh AND 16-16.5 tha-1 dry matter YIELD were the best cultivars, AND compared to the control cultivar (Tolidi-e-Karaj) showed 7% AND 10% superiority for the fresh AND dry matter FORAGE YIELD, respectively. There fore, these cultivars can be recommended for cultivation in Karaj.

Scince 1990 research on CLOVER has been commenced in Karaj AND other field stations of Seed AND Plant Improvement Institute, Iran. One of the achievements of this initiative is selection, improvement AND release of Alborz 1 CRIMSON CLOVER cultivar. New CRIMSON CLOVER cultivar, Alborz 1 was primarily selected from CLOVER germplasm received from Food AND Agriculture Organization (FAO), The United Nations, in Seed AND Plant Improvement Institute, Karaj, Iran. Agronomic AND YIELD trials were carried out in Karaj, Dezfoul, Arak, MazANDaran AND Esfahan. Demonstration plots AND research-extension verifications were performed in Karaj, Golpayegan AND Shahr-e-Kord. The important agronomic characteristics of Alborz 1 cultivar are: earliness, high fresh FORAGE YIELD in early spring season, suitability for being grown as second AND third crop in cropping systems as well as tolerant to diseases AND pests. Alborz 1 is also tolerant to deficit irrigation AND cold, therefore, it is also suitable to be grown in cold AND foothills areas. This cultivar is a reliable substitute for Berseem CLOVER in paddy cropping systems. Alborz 1 cultivar had very good performance in agronomy AND YIELD trails with 30-35 t ha-1 fresh FORAGE AND 5-5.5 t ha-1 dry FORAGE YIELDs of 16% protein content, 60% digestibility AND 70-80% platability.

To assess AND compare the preliminary YIELD of selected lines of persian CLOVER, an alphalatic design with two replications was carried out, the experiment had five blocks AND in each block 30 persian CLOVER lines were planted (sum of 150 lines). The results showed significant difference in 1% level probability for dry matter, protein AND digestiable protein YIELD. The comparison of means showed that the highest dry matter YIELD, protein AND digestiable protein YIELD beloned to line 37 (Eqlid-e-fars) with 14.82, 3.04 t/ha AND 2740.65 kg/ha, respectively. The superior lines beloned to seven populations of persian CLOVER (Eqlid-e-fars, Baladeh-e-Kazeroon, Mahali Zabol, Charmahale-e-bakhtiyari, Dochin-ekordestan, Famoor-e-kazeroon AND Hafftehchin-e-ShazAND). Mean comparison of quantitive AND qualitive FORAGE YIELD of superior lines compared with total mean showed that were higher 50.66%, 52% AND 51.33% from dry matter, protein YIELD AND digestiable protein YIELD respectively.

A field study was conducted to determine if earthworm activity AND mycorrhiza seperetely AND in combination, would affect the growth rate of berseem CLOVER (Trifolium alexANDrinum L.). The experiment conducted with four replicates under a rANDomized block design at the Seed AND Plant Improvement Institute, Karaj in May 2006. FORAGE YIELD of all harvesting except first cutting affected by Earthworm activity AND mycorrhiza. Increasing berseem FORAGE YIELD by earthworm activity caused through of enhancement of mycorrhoza infection rate. Phonological stages of berseem CLOVER weren’t influenced by both mycorrhiza AND earthworm activity.