JOURNAL OF CROP ECOPHYSIOLOGY (AGRICULTURE SCIENCE)
Year:2014 | Volume:8 | Issue:2 (30)|Papers Count:9

To study the thermal requirements of grain corn hybrids, at different planting dates, a field experiment was carried out in the Agricultural Research Center of Isfahan, Iran in 2007 - 2008. It was conducted in split plot arrangement based on randomized complete block design with three replications. Planting dates (June, 5- June, 20 and July, 5) were assigned to main plots and hybrids (BC404، KSC320، OSSK552، KSC500، OSSK713 and KSC704) to sub plots. Results indicated that there was no significant difference for growing degree-days (GDD) requirements from planting to germination among hybrids and planting dates. However, KSC704 hybrid in the first planting date needed the highest GDD during its different growth stages. KSC 500 hybrid with 6.31 (t/ha) and OSSK 713 hybrid with 6.48 (t/ha) produced the highest grain yields. The highest number of grains per ear row belonged to KSC320 Hybrid (18.83). KSC704, OSSK713, OSSK 552, and BC404 possessed the highest kernels per ear row, 44.63, 44.59 and 44.74 kernels respectively. The highest thousand kernel weight (288.12 g) was also observed in BC 404 hybrids. The highest protein content was related to the third planting date. However, its percentages in all hybrids, except KSC 320 hybrid, were similar. KSC 500 hybrid had the highest phosphorous content (243 mg/100g). The highest plant disease incidences were observed in KSC 320 and KSC 404 hybrids. KSC 704 hybrid, in the mean time, showed the highest ear contamination percentage. The conclusion is that OSSK713 hybrid and the second planting date produced the highest seed yield in Isfahan, Iran.

Application of microelements is one of the ways to increase quantative and qualitative characters of wheat. To evaluate the effect of zinc foliar application on yield and yield components of four wheat cultivars a factorial experiment with two factors was conducted in randomized complete blocks design with three replications in 2011-2012 year. The first factor consisted of four wheat cultivars (Falat, Bahar, Pishtaz and Tous) and the second factor composed of three levels of zinc chelate foliar applications (control, at shooting stage and at shooting + flowering stages). Zinc concentration in each application was decided to be 4 kilogram per hectare. Results showed that yield and yield components of cultivars were significantly different with each others. The highest and lowest yields were belonged to Bahar and Tous respectively. The highest yield of Bahar, as compared to the other cultivars, was due to its higher biological yield. Zinc foliar applications at shooting and shooting + flowering stages also increased biological and seed yields. Seed yield increase mainly affected by higher 1000 seed weight. In general, it seems that zinc application, due to its role in the physiology of wheat, a sensitive plant to zinc deficiency, may increase its seed yield.

To evaluate quantitative and qualitative characteristics and stability of marketable tuber yield of 13 promising potato clones, along with three commercial cultivars (Agria, Marfona and Lady Rosetta) as checks, an experiment was based on a randomized complete block design with four replications was carried out at the Agricultural and Natural Resources Research Station of Ardabil during 2011 and 2012. During the growing period and after harvest, attributes like number of main stem per plant, plant height, tuber number and weight per plant, total and marketable tuber yield, dry matter percentage, baking type, hollow heart, tuber inner ring and discoloration of raw tuber flesh after 24 hours were measured. Combined ANONA for quantitative traits showed that there were significant differences among promising clones as to total and marketable tuber yield, tuber number and weight per plant, plant height, mean tuber weight, number of main stem per plant and dry matter percentage and their interactions with year in total and marketable tuber yield and tuber number and weight per plant. The clones 396151-7, 397008-5, 397015-8, 397008-2 and 994001-4 were found to have higher total and marketable tuber yield, tuber number and weight per plant and mean tuber weight. These clones produced high and mid-uniform tuber, yellow skin color, yellow and white flesh color, oval round and round tuber shape, mid and shallow eyes, with no hollow heart, tuber inner crack and tuber inner ring, mid-late maturity and mid and high dry matter percentage as compared with control and other clones. In this experiment, GGE Bi-plot and AMMI models were found to be proper methods for selection of 397008-2, 397008-5 and 994001-4 as being high marketable and stable yielding clones.

To evaluate the response of agronomic characteristics of maize and cowpea to mycorrhiza and mesorrhizobial bacteria in intercropping, this study was carried out at the Research Field of Industrial Shahrood University in 2010 using a randomized complete block design with three replications. Treatments were: Z: maize monocropping, B: bean monocropping, I: intercropping of maize and bean, ZM: maize monocropping + mycorrhizae, BM: bean monocropping + mycorrhizae, BB: bean monocropping + mesorhizobuim bacteria, BMB: bean monocropping + mycorrhizae + mesorhizobium bacteria, IM: intercropping + mycorrhizae, IB: intercropping +mesorhizobium bacteria and IMB: intercropping + mycorrhizal +mesorhizobium bacteria. The results showed that treatment effects on seed yield per plant, leaf chlorophyll content, dry weight of cowpea pods, dry weight of maize ear, number of seeds per ear row, total biological yield in intercropping and partial land equivalent ratio of both cowpea and maize were significant (p<0.01). The highest seed yields per plant for cowpea and maize were 10 and 108 grams in monocropping of cowpea+ mesorhizobuim and monocropping of maize+mycorrhiza treatments respectively. Highest partial LER of maize and cowpea were respectively 1.7 and 1.47 in the intercropping and intercropping+ mycorrhiza fungi and mesorrhizobium bacteria treatments. The results showed that land equivalent ratio was more than one for maize and cowpea. This indicates a positive relations between members of mixed cropping against monocrpping and superiority of intercropping of maize and cowpea as compared to their monocroppings.

To study the effects of nitrogen and zinc fertilizer on the morphological traits and essential oil yield of St. John’s wort (Hypericum perforatum) a greenhouse experiment in a factorial randomized complete block design with three replications was conducted at University of Tabriz, Iran in 2012. Treatments consisted of three levels of zinc sulphate with a concentration of zinc fertilizer (zero, 3 and 6 parts per thousand) and four levels of nitrogen fertilizer (zero, 50, 100, 150 kg/ha). One half of the fertilizers were applied 20 days after planting of plants and the rest 40 days after transplanting. Traits evaluated were plant height, inflorescence number, leaf area, plant fresh and dry weights and plant essential oil content. The results showed that the traits under study were affected by rate of fertilizer applications. Highest plant height, number of inflorescences, leaf area and essential oil yield were obtained by using 150 kg/ha of nitrogen and applying zinc with 0.006 concentration. Highest fresh and dry weights of above ground parts were also produced by using 150 kg/ha of nitrogen fertilizer along with zinc fertilizer 0.003.

To investigate the effects  of rates of methanol foliar applications under water deficit stress on some of traits related to seed yield of sunflower (Helianthus annuus L.), a split plot experiment was conducted during growing seasons of 2011-2012. Treatments were four levels of water deficit stresses a1: severe stress (irrigation at 25% FC), a2: mild stress (irrigation at 50% FC), a3: fair stress (irrigation at 75% FC) and a4: normal irrigation (irrigation at 100% FC) and six levels of foliar methanol applications [b1:0, b2:7, b3:14, b4:21, b5:28 and b6:35 (v/v)]. The analysis of variance showed significant effect of interaction between water deficit stress  and methanol rates of foliar applications on seed yield per plant, dry weight per plant, number of seeds per head (p<0.01) and percentage of seed per fruit (p<0.05). The highest (96.69 g/plant) and the lowest (67.78 g/plant)  seed yields were related to the 21% [v/v] foliar application of methanol under normal irrigation and control (without methanol application) in severe stress  respectively (seed yield increase of about 42%). 21% (v/v) foliar application of methanol under normal irrigation also resulted in highest ( 53.34 g) and 0% (v/v) foliar application of methanol under severe stress in the lowest (31.42 g) oil yield per plant (69% increase). Also, 21% (v/v) foliar application of methanol under normal irrigation resulted in highest (465.4 g) and in severe stress had the lowest (191.5 g) dry weight per plant (a 2.4 fold increase in dry seed weight). Besides, the highest seed number per head was related to 21% (v/v) methanol foliar application under normal irrigation. Using 21% (v/v) methanol foliar application under normal irrigation increased seed number per head by 2.3 times in comparison with that of control under severe drought stress. The results also proved that 14% (v/v) foliar application of methanol under normal irrigation did increase seed (achene) yield by 32% and reduced percentage of ovary wall to seed by 2.1 fold.

German chamomile (Matricaria chamomilla L.) is one of the most important medicinal plants that its essential oils used in different medicinal industries. In this study which was carried out in 2013 growing season at the Faculty of Agricultural Sciences of the University of Mohaghegh Ardabili, the in vitro response of leaf and hypocotyl explants of German Chamomile in B5 medium supplemented with different levels of plant growth regulators including 2,4-D, naphthalene acetic acid (NAA), kinetin and 6-benzylaminopurine (BAP) were investigated in a factorial experiment based on completely randomized design (CRD). In addition, cell suspension cultures were established and characterized. Hypocotyl and leaf explants exhibited cell proliferation and produced callus within 1-2 weeks. The highest fresh weight of the callus (264.1 mg) was produced by leaf explants in the medium supplemented with 0.5 mg/l 2,4-D and 1 mg/l BAP. However, the leaf explants cultured on medium containing 1.5 mg/l 2,4-D showed the lowest cell proliferation and callus yield (40.42 mg). The highest percentage of root induction from leaf explants (58.73%) was observed on the medium containing 4 mg/l 2,4-D and 1 mg/l Kin, and from hypocotyl explants (48.61%) was observed on medium supplemented with 1.5 mg/l NAA. The 42.22% of calli derived from hypocotyl explants on B5 medium supplemented with 4 mg/l NAA and 3 mg/l BAP, were friable. Cell suspension cultures of German chamomile were established by transferring of hypocotyl-derived friable calli into the MS medium supplemented with 1.5 mg/l 2,4-D and 1 mg/l kinetin. The growth curve of cell proliferations started 4 days after culture and continued to grow until day 13th, where the cells entered stationary phase.

For recognizing exotic high performance genotypes, three new hybrid cotton genotypes (tbl180, Teskhi-9 and Cri108) were compared with control (Sahel) in a RCBD with four replicates at Khodafarin in 2012 and 2013. Genotypes were planted in six rows in 80×20 cm arrangement. Attributes like yield, homogeneity, boll number, plant weight and plant height were measured. Results showed that year×genotypes interaction for lint yield in both first and second cuts and total, and homogeneity were significant. Differences between two cuts were not significant in all genotypes. The results also revealed that Teskhi-9 having lowes TOL and highest STI values was recognized to be the most adaptable genotype as compared with other two genotypes.

This study was carried out to determine the requirements of cardinal temperatures and biological hours for germination of lentil by using different linear and nonlinear regression models. To do this, a split plot experiment based on randomized completely design with four replications was conducted in germinator. Experimental treatments were three lentil cultivars (Gacgsaran, Kimia and Bilehsovar) under seven fixed temperature regimes (5, 10, 15, 20, 25, 30 and 35oC). Beta, Dent-like and Segmented models were applied to evaluate the relationship between germination rate and temperature. Root mean square deviation (RMSD), coefficient of determination (R2), coefficients of variation (CV) and linear regression coefficients (a, b) were used to detect the perfect model. Results of fitting the models indicated that the response of lentil germination to temperature is best described by a segmented function. Cardinal temperatures estimated by this model were 0.89 to 1.23oC for base temperature, 23.41 to 26.94oC for optimum temperature and 35.15 to 45oC for ceiling temperature. Significant difference in base temperature among cultivars was not observed, but cultivars had significant difference in optimum and ceiling temperatures. Biological hour's requirement for germination ranged between 25.43 to 31.37 hours. The quantitative information provided by this research can be used in prediction of germination of lentil cultivars.