Showing 5 results for Seed Yield.
M. R. Khajehpour, A. R. Bagherian Naeni,
Volume 5, Issue 4 (1-2002)
Abstract
It is believed that various types of field bean, including pinto, white and red, differ in adaptability to high temperatures and may, thus, differ in response to delay in planting. In order to evaluate this response, an experiment was conducted during 1996 at the Agricultural Research Station, Isfahan University of Technology, using a randomized complete block design with split-plot layout. Main plots consisted of four planting dates (April 28, May 13 and 28 and June 13) and sub-plots included four genotypes of common bean (red bean, c.v. Naz pinto beans, experimental lines 11816 and 16157 and a white bean, experimental line 11805).
Number of branches per plant, number of pods per branch and per unit area, number of seeds per pod of main stem and branch, number of seeds per main stem, per branch and per unit area, 100-seed weight and seed yield significantly reduced, while harvest index significantly increased by delay in planting and consequent increases in temperature and reduction in time for growth. The lower harvest index obtained with early planting was the result of the lower efficiency of the produced vegetative growth due to the coincidence of seed filling period with high temperatures. Pinto bean line 11816 ranked the highest for number of branches per plant and harvest index among the genotypes evaluated and produced the highest seed yield (3030 kg ha-1). Although red bean Naz ranked the highest for number of pods and seed per main stem and per unit area, it had the lowest harvest index and 100-seed weight and, consequently, produced the least seed yield (2254 kg ha-1). The results obtained indicate that delay in planting adversely affects bean seed yield. Pinto bean line 11816 may have higher yield potential among the genotypes studied at all planting dates under conditions similar to the present experiment. No specific relationship was observed between apparent seed characteristics and plant tolerance to heat.
M. Jamshid Moghaddam, S. S. Pourdad,
Volume 10, Issue 2 (7-2006)
Abstract
To evaluate seed germination and seedling growth of safflower in moisture stress, germination of 15 genotypes at four water potential levels (ψ: 0, -0.4, -0.8 and –1.2 Mpa) was tested by Polyethylene glycol (PEG6000). Maximum germination (Gmax), germination rate index (GRI), time length to reach 50% germination (T50), rootlet length (RL) and shootlet length (SL) were investigated. Effects of water potential levels and genotypes were significant for all the characteristics studied. Minimum water potential for germination was estimated between –1.17 and –1.59 Mpa in Goshkhani and LRV-51-51 genotypes, respectively. Different responses to moisture stress were found for rootlet length. In lower potential levels, seedlings had longer, weaker and thiner rootlets in comparison to the zero water potential (control). An increase in stress to –1.2 Mpa led to a severe reduction in rootlet elongation. All stress levels decreased GRI and SL, while potentials lower than –0.4 Mpa decreased Gmax. With a decrease in water potential from 0 to –0.8 Mpa, the T50stage was delayed three-fold compared to the control. Exotic genotypes had longer T50 stage than Iranian genotypes. The highest GRI was related to three Iranian genotypes LRV-51-51, Varamin 295, and Isfahan local, and the lowest was related to CW-74 exotic genotype. Some of genotypes were evaluated for seed yield, oil yield and seed oil percentage under rainfed condition in 2004-05. The highest oil yield average belonged to two exotic genotypes PI- 537598 and Lesaf (326.4 and 313.9 Kg/ha, respectively) and the least was related to Zarqhan 279 Iranian genotype (133.2 Kg/ha). Negative and significant correlation was observed between seed oil percentage and GRI in the 0, -0.8 Mpa potential levels. According to the results, the existing genetic variation for germination parameters can be used for genetic improvement of seed early vigor in safflower.
M. R. Pordel, B. Hatami, M. Mobli, R. Ebadi,
Volume 10, Issue 4 (1-2007)
Abstract
Canola (Brassica napus) is one of the important oil seed crops cultivated in many parts of Iran. One of the main problems of seed production of canola is pollination and fertilization of flowers. Insects are the major pollinators. In order to study the fauna of insect pollinators of 3 cultivars of canola including Talaye, Okapi and S.L.M. and the difference between the attractiveness of these cultivars to insects during the flowering period, insects were collected by sweeping net and identified. Their abundance was determined at different periods of time during a day. Results showed that insect pollinators belonged to five orders and 18 families. The most abundant pollinators were Hymenopterous insects specialy honey bees (Apis mellifera) which were about 50%. Irrespective of Apis mellifera, the most abundant insects captured belonged to Diptera. Three Dipterous insects, Bibio hortulanus, Metasyrphus corollae and Platypalpus sp. were collected and identified. During the flowering period (March to mid April) in Isfahan, honey bees were more abundant in the warmer hours of the day, mostly noon and afternoon, but were less active in the early hours of the day, morning, because of cold weather and low nectar production. Honey bees were more active than other pollinators on Talaye at 9 a.m. and on Okapi at mid-day, noon, and during afternoon. Results also showed that insect pollinators could increase seed yield by 53%.
M. M. Majidi, A.f. Mirlohi, M.r. Sabzalian,
Volume 11, Issue 41 (10-2007)
Abstract
Fescues (Festuca spp) are widely distributed in the temperate regions and are used for turf, forage and soil conservation. Though seed traits are important measures of the effects of endophytic fungi on their host, little information is available in this respect for Festuca. In this study, endophyte-infected (E+) and endophyte-free (E-) clones of the six fescue genotypes were used to investigate the effects of endophyte on seed production. The relationships between seed traits plus direct and indirect effects of components on seed yield were also studied. Endophyte infection resulted in 38.1% to 249% more seed yields in some genotypes, though some were not affected by this symbiotic relationship. Correlations between traits and also results of stepwise regression were influenced by the presence of the symbiotic fungi. Path analysis showed that endophytic fungi changed direct and indirect effects of components on seed yield. In endophyte containing clones, panicle fertility had the most direct effects and number of panicle per plant and seed per panicle the most indirect effects on seed yield. In E- clones, panicle fertility had the highest indirect effects and other components had direct effects on seed yield. The results suggested that breeding strategies for increasing seed yield in fescue should consider the presence or absence of endophyte in germplasm.
H. Pourhadian , M.r. Khajehpour,
Volume 11, Issue 42 (1-2008)
Abstract
Planting patterns through growth indices affect yield formation. To evaluate these effects on safflower, Koseh local variety of Isfahan, a field experiment was conducted in summer, 2004 at the Agricultural Research Station, Isfahan University of Technology. The experiment was performed using a randomized complete block design with a split plot layout and four replications. Main plots consisted of three row distances (20 and 30 cm flat and 45 cm on bed), and sub-plots included two planting densities (40 and 50 plant m-2). The experiment was planted on June 25. The results showed that p lant canopy closed sooner, leaf area duration (LAD) increased and plant dry matter weight, leaf area index (LAI) and crop growth rate (CGR) were higher up to the middle of seed development as row distance decreased. In addition, the highest relative growth rate (RGR) and net assimilation rate (NAR) were obtained in 20 cm row distance. The highest (3039 kg ha-1) and lowest (1930 kg ha-1) seed yields were obtained with 20 and 40 cm row distances, respectively. Plant density did not affect the rate of canopy closure, CGR, RGR, NAR and seed yield. But, maximum plant dry weight, higher LAI and lower LAD values were obtained with 50 plants m-2. The results obtained in this experiment indicate that 20 cm row distance with 50 plants m-2 might be appropriate for summer planting of safflower, a local variety of Isfahan, under similar conditions.
