SEED AND PLANT PRODUCTION JOURNAL
Year:2013 | Volume:29-2 | Issue:2|Papers Count:8

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.

To evaluate advantages of mixed cropping of annual forage legume crops grass pea (Lathyrus sativus L.), field pea (Pisum avestum L.), hairy vetch (Vicia villosa L.) and Hungarian vetch (Vicia panonica L.) with barley (Hordeum vulgare L.) in two seeding ratios 3:1 and 1:1, a field experiment was conducted at Khodabandeh dryland agriculture research station in 2009-2011 growing seasons. The field experiment was arranged in randomized complete block design with 13 treatments and four replications. Combined analysis of variance revealed that effect of treatments were significant (P<0.01) on dry matter yield (DMY), crude protein yield (CPY) and land equivalent ratio (LER). The highest DMY (6.46 t ha-1) and CPY (0.54 t ha-1) were obtained from the sole barley and mixed cropping ratio of 75% field pea+25% barely. Higher relative crowding coefficient (KBarley=2.96-4.85) index for barley compenent in mixed cropping treatments indicated that barley was dominant species. Among the mixed cropping treatments the mixture ratio of 75% field pea+25% barely with CPY of 0.54 t ha-1, LER of 1.11, system productivity index of 2.92, relative crowding coefficient indexof 1.55 and monetary advantage index of +72.7 was determined as the most suitable mixed cropping ratio for rainfed conditions of Zanjan Province in Iran.

This study was carried out to determine the suitable sowing time and seeding rate and their effects on seed yield and some agronomic traits of kabuli chickpea lines (Sel93TH24460 and ILC482) using split-plot factorial arrangements in randomized complete block design with four replications in two cropping seasons (2008-10) in Saral experimental station of Kurdistan Province in Iran. Main plots included two levels of sowing time (early October and early November) and sub-plots consisted of the factorial arrangements of seeding rate (25, 35 and 45 plants m-2) and chickpea genotypes. In the first year entezary planting of Sel93TH24460 with 45 plant m-2 (100 kg seed ha-1) and in the second year autumn sowing of same line with 25 plants m-2 (60 kg seed per ha-1) produced the highest seed yield. Combined analysis of variance revealed that autumn sowing of Sel93TH24460 combined with 45 plant m-2 gained the highest seed yield over teo years with no significant difference with 35 plant m2 (80 kg seed ha-1). In general, Sel93TH24460 was significantly superior to ILC482, and autumn sowing in cropping season with adequate snow and rainfall was better than entezary planting system. It is concluded that 45 plant m-2 with adequate moisture supply and appropriate rainfall distribution will produce higher seed yield. Based on the results of this research, autumn sowing of Sel93TH24460 with 35 plant m-2 (seed rate of 80 kg ha-1) could be recommended as the suitable package for autumn sowing of chickpea in rainfed conditions of Kurdistan Province in Iran.

This study was carried out to evaluate phenology, yield and yield components of canola cv. Hyloa 401. The experiment was conducted in randomized complete blocks design with four replications and five sowing dates from 22 October to 30 November with 10 days intervals in 2006-07 and 2007-08 cropping seasons in Khuzistan Agricultural and Natural Resources Research Center, Ahwaz, Iran. Results showed that sowing date had significant effect on all traits, but interaction effect of year x sowing date had no significant effect on sowing to emergence duration, seed per-1 pod and thousands seed weight. The shortest sowing to emergence duration, the longest sowing to flowering and maturity duration the tallest plant height, the highest pod no. plant-1, seed no. pod-1, thousands seed weight, seed and oil yields were produced in 22 October sowing date. Based on regression equations, each day delay in sowing date caused about 1% reduction in seed and oil yields. Therefore, the delay in sowing date reduced vegetative and reproductive stage duration and caused instability in seed yield. In conclusion, 22 October to 31 October could be considered as optimum sowing date, however, 31 October to 10 November with 20% reduction in seed and oil yield production could also be recommended as the alternative sowing date in Khuzistan Province conditions.

To evaluate soybean cultivars in different planting arrangements and densities, three field experiments were conducted in 2006 and 2007 growing seasons in Gorgon agricultural research station. Three soybean cultivars; Sepideh, Sahar and Katoul were planted in different planting arrangements and densities on one and twin rows on beds with 50, 75 and 85 cm row spacings. Three separate experiments were carried-out as split-plot arrangements in randomized complete blocks design with three replications, for each soybean cultivar. Combined analysis of variance revealed significant differences between two growing seasons. All soybean cultivars had less seed yield in 2007 growing season. Sepideh performed significantly different in different row spacings and produced the highest seed yield (2459 kg ha-1) in twin rows with 75 cm row spacing and 500000 plant ha-1. Sahar, however, produced the highest seed yield (2560 kg ha-1) in one rows with 50 cm row spacing. It also had the highest seed yield with 300000 plant ha-1. Katoul produced the highest seed yield (2992 kg ha-1) in twin rows with 75 row spacing. It can be concluded that soybean cultivars responded differently to different planting arrangements and plant densities. Therefore, to obtain the seed yield potential, each cultivar must be planted in its suitable planting arrangement and density.

To assess fruit yield and quality of tomato varieties in one and many hand-harvesting a field experiment was carried out using factorial arrangement in randomized complete blocks design with four replications in 2010 and 2011 cropping seasons in Agricultural and Natural Resources Research Center of Khorasan Razavi Province, Mashhad, Iran. Three determinate tomato hybrid varieties with simultanous rippening and suitable for processing; Hypeel 108, Hypeel 303 and Hypeel 347 along with PetoPride 2 as check cultivar, and number of harvesting; one and many times hand-harvesting were the experimental factors. Combined analysis of variance revealed that tomato varieties significantly differed in fruit weight plant-1, total fruit yield and brix index. Mean comparison showed that Hypeel 347 was superior to PetoPride 2 by 26.9%, 26.9% and 11.9%, respectively. Number of hand-harvesting times had also significant effect on all traits except pH and brix index. Mean times of hand-harvesting had higher number of fruits plant-1, fruit weight plant-1 and total fruit weight and was superior to one time hand-harvesting by 14.1%, 13.1% and 131%, respectively. However, the required number of labor was greater in several times of hand-harvesting.

To study chlorophyll fluorescence attributes and physiological traits of some clover species in low temperature conditions a field experiment was carried out in 2011-2012 cropping cycle in Seed and Plant Improvement Institute in Karaj, Iran. Ten clover genotypes and three sampling times were arranged as split-plot in randomized complete blocks with three replications. Results showed that clover genotypes were significantly different in chlorophyll fluorescence attributes and physiological traits. Fv/Fm ratio (0.597-0.755) showed that low temperature stress affected clover genotypes. The highest Fv/Fm ratio belonged to Persian clover and the lowest was estimated for Red clover which were indentified as most tolerant and susceptible genotypes, respectively. Chlorophyll content index (CCI) had the highest significant correlation with chlorophyll fluorescence attributes in dark conditions. Considering the results of this research, Fv/Fm, electrolyte leakage (EL) and CCI were identified as suitable criteria in selection for cold tolerance of clover genotypes.

One of the most important factors in successful grafting of woody plants is inhibition of oxidation of phenolic substances which results in formation of suitable callus between rootstock and scion. For this reason, the effect of antioxidant (PVP), auxin (IBA) and cytokinin (BA) in four different times (early January, February, March and early May) on walnut minigrafting was investigated. Results showed that the most suitable time for minigrafting is February with 83.24% grafting success. Grafting success and scion growth in antioxidant concentrations was significantly different from control. Among antioxidant and hormone treatments the combination of 50 mg l-1 IBA and 80 mg l-1 BA with 83.94% grafting success and minimum grafting duration (21 days) was the superior treatment. Antioxidant treatments also required the minimum grafting duration. In conclusion, 50 mg l-1 and 80 mg l-1 of BA in February is recommended for improving walnut minigrafting process.