SEED AND PLANT PRODUCTION JOURNAL
Year:2011 | Volume:26-2 | Issue:4|Papers Count:15

Changes in some of defense compounds such as peroxidase enzyme activity and amount of total phenol in treated Golden Delecious apple fruits with an antagonist isolate of Pseudomonas fluorescens (isolate F7) and Penicillium expansum, the cause of blue mould was studied. Extraction and measurement of peroxidase enzyme activity and total phenol was performed in 3, 6, 9 and 12 days after inoculation of the fungus. Results showed that in simultaneously inoculated apple fruits with the bacterium and pathogen, peroxidase enzyme activity and total phenol increased significantly as compared to the control. Maximum peroxidase enzyme activity and total phenol were recorded nine days after inoculation of fungus. Results suggested that increase in peroxidase enzyme activity and total phenol can be attributed to induction of the defense compounds in apple fruits by P. fluorescens isolate.

To evaluate the competitive effects of lambsquarters (Chenopodium album L.) on phenology and grain yield of maize (Zea mays), cv. hybrid 604, an experiment was carried out at Kakaj, Tabriz, Iran in 2008 growing season. Factorial experiment was established in randomized complete block design with three replications. Treatments included; combination of five lambsquarters densities (1, 4, 8, 12 and 16 plants m-1 of row) and four relative times of weed emergence (emerged with maize; 10, 20 and 30 days after maize emergence) and a weed free control plot. Results revealed that 30 days delay in weed emergence, phyllochron in maize decreased by 1.5 days. Days to tassel emergence increased from 61 days in weed free plot to 66 and 67 days in 12 and 16 weeds per meter of row, respectively. Weed competition caused a significant loss in maize yield. Time of weed emergence was more effective on grain yield loss than weed density. Grain yield loss in maize at different weed emergence times were 64%, 38%, 15%, 8%; and at different weed densities were zero, 23%, 35%, 46%, 53%, respectively. Two parameters model of Cousens et al., (1987) was of higher precision and efficiency in estimating of grain yield of maize.

To evaluate and compare yield, yield components and morphologic characteristics in winter rapeseed varieties (Brassica napus L.) adapted to cold dry regions of Iran and to determine high yielding rapeseed varieties, a field experiments was carried out in 2006-2007 and 2007-2008 cropping seasons in experimental field of Agricultural and Natural Resources Research Center of Markazi Province, Arak, Iran. Fifteen winter rapeseed varieties were evaluated using randomized complete block design with three replications. Results showed that Licord, Modena and Okapi varities had greater seed yield as compared to others. A second experiment was carried out in 2008-2009 cropping season in the same site to assess the effect of organic and chemical nitrogen sources on seed yield, fatty acids composition and micro nutrient contents in high yielding rapeseed (Brassica napus L.) varieties. The experiment was arranged as factorial in randomized complete block design with three replications. Three rapeseed varieties (V1 = Okapi, V2 = Modena and V3 = Licord) and three sources of nitrogen based on 150 kgN/ha (N1 = Azocompost, N2 = 50% Azocompost + 50% Urea and N3 = Urea) comprised the experimental factors. Results showed that Licord had the highest seed yield, glucosinolate, stearic and  linolenic acids, Iron (Fe), Zinc (Zn), Copper (Cu) and Manganese (Mn) contents. Integrated nutrition management showed superior to other treatments for seed yield, micro nutrients content such as Cu and Mn. Results also showed that with seed yield increase, the quality of canola oil declined. Azocompost enhanced the quality of canola oil, but integrated nutrition management and Licord combination increased seed yield.

To study the effect of sowing date and plant density on some agronomic characteristics, seed yield and its components of soybean genotypes, a field experiment was conducted in Moghan Agricultural Research Center in 2007 and 2008 cropping seasons. The experimental design was split split plot arrangment in randomized complete block design, with three replications. The main plots included sowing dates; 15 June, 01 July, 16 Jul and 01 August, and sub-plots comprised of three soybean genotypes; Hamilton × Essex, L17 and Williams. Three plant densities 30, 40 and 50 plant/m2  were randomized in sub-sub plots. Combined analysis of variance for two years data showed that seed yield was affected by sowing dates. The highest and lowest grain yield were obtained from 15 June (3593 Kg/ha) and 01 August (2609 Kg/ha) sowing dates, respectively. There were significant differences among genotypes for agronomic characteristics and seed yield. By increasing plant density, plant height and number of seed per m2 increased, but number of pod per plant decreased. Density of 50 plants per m2 had the highest seed yield. Hamilton × Essex produced the highest grain yield (3784 kg/ha) in 15 June with 50 plants per m2.

To determine effects of vermicompost cow dung + sawdust (80% to 20% volume) with peat in peat + perlit (1: 2 ratio) growth media on ornamental plant (Dieffenbachia amonea) an experiment was carried out. Initially sawdust was introduced to worm and then vermicompost was produced, rooted stocks planted in peat+ perlit (1: 2 ratio) and beds with 25, 75, 50, 100% vermicompost of cow dung + sawdust was substituted with peat (peat+ perlit). Nitrogen, phosphorus, potassium, calcium, magnesium in plant leaves and growth media, plant height, stem diameter, shoot and leaf fresh and dry weight, root fresh and dry weight of plant were measured. Results showed that the increase in vermicompost cow dung + sawdust substituted with peat significantly (P £ 0.05) increased nitrogen, phosphorus, potassium, calcium and magnesium in Dieffenbachia plant leaves and growth media. 50% vermicompost of cow dung + sawdust had the highest plant height(10.23 cm). 25% vermicompost of cow dung + sawdust had the greatest stem diameter (23.46 mm), shoot and leaf fresh (56.81 g) and dry (5.83 g) weight, root fresh (64.07 g) and dry (6.21 g) weight. By increasing vermicompost of cow dung + sawdust, water holding capacity in media increased as the %100 vermicompost of cow dung + sawdust had the highest water holding capacity (73.6%).

Response of grape cv. Siah-e-Samarghandi to pruning severity (light pruning; 40 + 20 and severe pruning; 20 + 20) and the length of cane (3, 6 and nodes) was evaluated in Bavanat region, Fars, Iran, in 2004-2007 growing seasons. Factorial arrangement in randomized complete block design with three replications was employed for evaluation of concerned treatments. Results showed that effect of pruning severity was significant on yield and %TSS (P£0.05), and cluster weight, cluster/vine and bud fruitfullness (P£0.01). Effect of cane length was also significant (P£0.01) on yield, cluster/vine and bud fruitfullness. Pruning severity × cane length interaction was significant (P£0.01) on yield, cluster/vine, cluster weight, %TSS and bud fruitfullness. Light pruning with three buds for cv. Siah-e-Samarghandi is recommended.

To determine the effect of type of polyethylene bags and position of sulfur pads on decay control, fruit quality and sulfite residue in grape cv. Rasha during cold storage in 2007 and 2008. Three different levels of SO2 generating pads (one on top, half on top and half on bottom of the packaged grapes and without sulfur pad) that composed of 1g kg-¹ sodium metabisulfite combined with two types of polyethylene bags (perforated and imperforated) during cold storage (135 days) on some traits such as: berry weight loss (%), bleaching, fungal rot (%), rachis desiccation, shriving, taste and sulfite residue was measured. Results showed that SO2 generating pads treatment during the storage significantly decreased berry weight loss, rachis and berry shriving, decay rate and fungal rots. Whereas, off flavors, bleaching and sulfite residue in grapes were increased. Imperforated bags treatments significantly decreased berry weight loss, rachis and berry shriving. The highest sulfite residue, 17.5 and 15.6 ppm, were observed in one and two sulfur pads treatments with perforated bags, respectively. Whereas in imperforated bags, sulfide residue was 9.3 ppm at both sulfur pad treatments. To increase the shelf life, decrease bleaching and off flavor of grape cv. Rashe in cold storage, one SO2 generating pad on top of packaged grapes with perforated polyethylene bags or half pad with imperforated bags is recommended.