SEED AND PLANT PRODUCTION JOURNAL
Year:2011 | Volume:27-2 | Issue:2|Papers Count:8

Response of some bread wheat (Triticum aestivum L.) lines and cultivars to vernalization was studied in cereal physiology laboratory and glass house, Seed and Plant Improvement Institute, Karaj, Iran, in 2006-2007. Twenty nine bread wheat lines and cultivars and 9 levels of vernalization duration including, 0, 8, 15, 22, 29, 36, 43, 50 and 57 days at 3±0.5oC were evaluated using randomized complete block design with three replications. Imbibed seeds were planted in pots and exposed to different vernalization treatments. Results showed that bread wheat lines and cultivars responded differently to vernalization treatments and varied from true spring (Kavir) to facultative (Sharyar, Sisson, C-18-14 and C-80-6) and true winter (Gascogne, MV17, Bezostaya and C-80-4). However, the majority of genotypes showed facultative response. The minimum duration of vernalization requirement, based on days to heading, was two weeks for Sharyar, three weeks for Gascogne, C-80-4, C-80-6 and four weeks for Sisson, MV17 and C-81-14, in 3±0.5oC.

To evaluate the effects of tillage systems and rice residue management on yield components, grain and oil yields of rapeseed (Brassica napus L.) as second crop in paddy fields, a factorial experiment was conducted using randomized complete block design with three replications at Rice Research Institute of Iran (RRII), in 2003-2004 and 2004-2005 cropping seasons. The experimental factors were tillage systems at three levels, no tillage, minimum tillage (one pass rotivator in depth of 10-15 cm) and conventional or complete tillage (moldboard plow in depth of 30 cm and rotivator) and rice residue management at two levels (R0: without residue and R1: with residue). Plant density, silique number per plant, grain number per silique, 1000-grain weight, biological yield, harvest index, oil percent, grain and oil yields and C:N ratio were measured. Results showed that there was a significant difference between tillage systems for grain and oil yields, biological yield, harvest index, plant density and silique number per plant. In addition, the effect of rice residue management and interaction of tillage system × residue management was not significant on any of the characteristics, except plant density. No tillage system with residue had the lowest grain and oil yields. Minimum tillage system (2033 kg/ha) and conventional tillage (2255 kg/ha) showed no significant difference for grain yield, however, they were significantly different from no tillage system (1455 kg/ha). Results also showed that despite the higher grain yield in conventional tillage system, minimum tillage system with and without residue had relative advantages due to reducing the costs of tillage operations.

To determine the effects of different levels of irrigation and streptomyces bacterium on grain yield and its components of maize cv. KSC260 a field experiment was carried out. The experiment was carried out as stripe split plot arrangments in randomized complete block design with three replications in 2009 and 2010 growing seasons in Seed and Plant Improvement Institute Karaj, Iran. Experimental factors included: three levels of irrigation (A), 70, 100 and 100 mm evaporation from standard evaporation pan (class A) as optimum, mild stress and severe stress, respectively, and four bacterium treatments (B), control (no chemical fertilizer and no bacterium), fertilizer, bacterium + fertilizer and bacterium. Results showed that irrigation levels significantly (P<0.01) affected leaf dry weight, leaf area index, leaf chlorophyl index, plant height, ear length, ear diameter, biological yield, kernel no. row-1 1000 kernel weight and grain yield. Irrigation levels also significantly (P<0.05) affected days to silking, anthesis to silking interval, ear height, stem diameter and ear no. plant-1. Bacterium treatments also had significant (P<0.01) effect on days to anthesis, days to silking, leaf number, leaf dry weight, leaf area index, leaf chlorophyll index, stem diameter and ear diameter. It also had significant (P < 0.05) effect on days to tasseling, ear number, row no. ear-1, 1000 kernel weight. The highest and lowest grain yields were obtained from optimum irrigation (5649 kgha-1) and severe stress (3574.5 kgha-1) conditions. It was concluded that the highest performance of cv. KSC260 was in optimum irrigation with application of Streptomyces bacterium and nitrogen and phosphorous.

Economic assessment of mixed cropping of alfalfa with irrigated annual cereals, barley, oat and triticale was conducted. A field experiment with 13 treatments was carried out-using randomized complete block design with three replications. For economic analysis, partial budgeting technique was used. Results showed that mixing 20 kgha-1 of alfalfa seed with 150 kgha-1 of oat seed was the most profitable treatment. Net profit of this selected mixed cropping was estimated of 4285.2 million Iranian Rials (IRR) that was greater than net profit of other treatments. Breakeven point of cost for selected treatment (20 kgha-1 of alfalfa seed with 150 kgha-1 of oat seed) as compared to the second and third treatments of priority indicated that even the mean costs of selected treatment (20 kgha-1 of alfalfa seed and 150 kgha-1 of oat seed) increased by 2.8% of second (20 kgha-1 alfalfa seed and 200 kgha-1 of triticale seed) and 5.1% of third (20 kgha-1 of alfalfa seed and 200 kgha-1 of oat seed) treatments, still it was the selected treatment. Breakeven point for gross income for the selected treatment (20 kgha-1 of alfalfa seed and 150 kgha-1 of oat seed) was 23959.2 IRR and 23492.7 IRR as compared with the second (20 kgha-1 of alfalfa seed and 200 kgha-1 of triticale seed) and third (20 kgha-1 of alfalfa seed and 200 kgha-1 of oat seed), respectively.

Nine bread wheat and one durum wheat genotypes were evaluated under non-stress, mild and severe terminal drought stresses conditions at Darab Agricultural Research Station in three cropping seasons (1998-2001). Split plot arrangements in randomized complete block design with there replications was used. Main plots included: three moisture regimes (1. non stress, 2. mild drought stress: 25% reduction of water requirement from 50% anthesis of local check cultivar (Chamran) and 3. severe drought stress: 50% reduction of water requirement from 50% anthesis of local check cultivar (Chamran). Ten wheat genotypes were randomized in sub-plots. Results indicated that mild and severe drought stresses significantly (P<0.05) decreased grain yield for all genotypes. Main reason for grain yield reduction in mild drought stress (21.8%) and severe drought stress (40.7%) was reduction in grain number per spike and thousand grain weight, respectively. Genotype no. 6 produced the highest grain yield (5352 kg ha-1) in non-stress conditions. The highest grain yield in mild drought stress (4178 kg ha-1) and severe drought stress (3505 kg ha-1) conditions was obtained from genotype no. 9. Stress tolerance index (STI), geometric mean productivity (GMP) and mean productivity (MP) showed the highest correlation with the grain yield in non-stress, mild and severe drought stresses conditions. Therefore, these indices are suggested for selection for drought tolerant genotypes. According to these indices, genotypes no. 6 and 9 were the most tolerant genotypes under mild and severe drought stresses, respectively. Correlation analysis showed that biological yield and harvest index had significant and positive correlations with grain yield in all three moisture regimes. Therefore, genotypes no. 6 and no. 9 are suggested to be used in wheat breeding programs for improving terminal drought tolerance.

To study the effect of biofertilizer phosphate on grain yield and its componants of maize cv. KSC704 under deficit water stress conditions, a field experiment was carried out in Ilam Agricultural Research Field Station, Ilam, in 2008 and 2009 growing seasons. Split factorial arranagements in randomized complete block design with three replications was used. Main plots were assigned to three irrigation levels, irrigation after 70= I1, 100= I2 and 130= I3 mm cumulative evaporation from class A evaporation pan. Sub-plots consisted of factorial arrangements of two levels of biofertilizer phosphate, B0= no biofertilizer phosphate and B1= with biofertilizer phosphate and three levels of chemical phospours fertilizer, P1=0, P2=45 and P3=90 kgha-1. Results showed that biofertilizer phosphate significantly increased grain yield in the water deficit conditions (I2 and I3). The highest grain yiled (9090 kgha-1), yield components and HI was obtained from integrated application of biofertilizer and 45 kgha-1 chemical fertilizer in optimum irrigation regime. However, in mild water deficit stress conditions, the highest grain yield (8098 kgha-1) was also obtained by application of the same fertilizer treatment. 1000 KW was also heavier for this fertilizer treatment in I1 with 356.6 g, and it was 335 g in I2. It can be concluded that biofertilizer phosphate could improve tolerance of maize plant to water deficit stress and reduce the usage of chemical fertilizer.

To evaluate effect of nitrogen and zinc fertilizers on leaf zinc and chlorophyll contents, grain yield and chemical composition of two maize hybrids, KSC704 and KSC540, a field experiment was carried out at the experimental farm of Shiraz University, Bajgah, Shiraz, in 2007. Factorial arrangements in randomized complete block design with three replications were used. Three levels of nitrogen, as Urea, including, 120, 260 and 400 kgha-1, and three levels of zinc, as Zinc sulphate, including, 0, 15 and 30 kgha-1, in factorial arrangments were assigned to main plots, and two maize hybrids, KSC704 and KSC540 were raindomized in sub-plots. Results showed that the highest grain yield was obtained from combination of 260 kgha-1 Urea and 30 kgha-1 Zinc sulphate. Nitrogen had significant (P<0.05) on leaf chlorophyll content measured by SPAD. The highest SPAD value belonged to combination of 260 kgha-1 Urea and 15 kgha-1 Zinc sulphate. Interaction of nitrogen × zinc was significant (P<0.05) on leaf and grain zinc contents. Increasing zinc increased nitrogen absorption. It was concluded that application of appropriate combination of nitrogen and zinc would improve the grain quality and yield of maize under similar conditions.

Indian Ber (Ziziphus mauritiana) has growing type as grape and is inclined to horizental and down ward growth. If it is not trained appropriately, it would grow into very bushy with thiny shoots. Hence, such trees have short lives, and are liable to pests and diseases with low yield. Fruit harvesting is also difficult in bushy trees. Therefore, proper pruning and training of young trees is essential for having strong trees. The effects of grafting height, scion number and timing of rootstock cutting back on the rate of graft joining in three Indian Ber cultivars was studied using factorial arrangements in randomized complete block design with three replications. Experimental factors included: grafting height at two levels (20 and 30 cm), number of scions at two levels (2 and 3 scions with 180o and 120o angle, respectively), timing of rootstock cutting back at two levels (immedately and 30 days after grafting) and Indian Ber cultivars at three levels (IX, XI and XX). Results showed that rootstock cutting back immedately after grafting had significant effect on the rate of graft joining due to elimination of apical dominance. Number of scion had no significant effect on the rate of graft joining and length of scion. Grafting height significantly affected the length of scion as grafting at 30 cm height increased the length of scion in comparison with 20 cm.