THE SCIENTIFIC JOURNAL OF AGRICULTURE (SJA)
Year:2001 | Volume:24 | Issue:1|Papers Count:7

Soybean plant uses nitrogen from symbiosis systems. Some field experiments indicated that application of amount of N reduce N deficiency in soybean plant. Effect of N probably influences plant density and planting pattern which effect on grain yield. The experiment was conducted as a split plot design in 4 replications for 2 years 1998 and 1999 in Dezful Agricultural Research Station. Main plots were 3 level of N fertilizer as urea (N0 =without N application, N1 = 50 kg/ha and N2 =100 kg/ha). Nitrogen fertilizer was applicated in V3-V4 vegetative growth stage. Subplots were allocated to 2 plant density (D1= 25 and D2= 35 plant/m2) and planting pattern (P1= 50 cm and P2 =70 cm) in factorial. Combined analysis indicated that N starter fertilizer increased total dry matter and grain yield. High radiation interception in canopy was due to increased leaf area which influence biological matter and grain yield. Among yield components, seed number per m2 showed highest sensitivity to N fertilizer. Number of pod per m2 increased with high plant density. It seems to be high plant density with application of N fertilizer increase grain yield. The amount of solar radiation interception by crop canopy was increased with 50 cm interval between rows planting. Effects of N fertilizer, high density with pattern of 50 cm was more efficient on growth and yield. Grain quality (protein) was relatively improved by (3. 23%) those treatments.

About 50 to 80 percent of poultry diets, is consisted of energetic food stuffs like wheat, barley and corn. Since hulless barley is consisted of high rate of energy and protein, it can be replaced instead of corn to supply some part of the required poultry diets. In order to succeed in doing this replacement, hulless barley feeding value and estimating of metabolisable energy level are needed. By using the biological Sibbald method (1976), the metabolisable energy of hulless barley and corn was estimated. For this experiment, adult roosters from meat breed (Arian) were used. They were divided in 11 groups and each group contained 6 roosters. Each group was forced to feed, 30 gr hulless barley or 30 gr corn. One group was kept in fasting state. This experiment was done in 25 0C and in a completely randomized unpaired design. The results of this experiment indicated that AME, TME, TMEn of hulless barley and corn were 3.68, 4.21, 3.32 and 3.74, 4.31, 3.56 Kcal/g respectively. There was no significant difference between the metabolisable energy content of hulless barley and corn (P<0.01). Therefore, hulless barley can be recommended in poultry diets instead of corn, because of its feeding value and cost.

The most important viruses of potato are potato viruses Y and X. The Purpose of the present study was to purify PVY and PVX isolated from potato fields of Khuzestan province and to prepare an antiserum against each of them in order to develop a sensitive serological test for diagnosis of these viruses. Potato Y and X viruses were isolated from potato fields in Khuzestan and propagated in Nicotiana tabacum cv. Samsum under greenhose conditions. Both viruses were purified by a modification of the method of McDonald et al., 1976. Rabbits were used to raise polyclonal antisera against each of the purified viruses. The produced antisera had a titer of 128 for PVY and 256 for PVX in microprecipitin test. Enzyme linked immunosorbent assay (ELISA) and dot immuno-binding assay (DIBA) systems were developed for both viruses, were quite suitable for detecting viruses in infected plants. No reaction was obtained between the antisera and healthy potato sap.

In order to evaluate the split of nitrogen appilcation rate on grain yield and yield components, a field experiment was conducted (in two years from 1995-1997) at Ramin Agricultural Research and Education School. The design of the experiment was a factorial in randomized complete block design with four replications. Experimental factors were two wheat cultivars (Atila and Kauz) and split rate of N application in which was arranged to five levels N1(%50, %50, 0, 0), N2(%25, %50, %25, 0), N3 (0, %50, %50, 0) , N4(0, %25, %50, %25) and N5(%25, %25, %25, %25) at four growth stages, (planting time, early stem elongation, and ear emergence and anthesis) respectively. Results indicated that kauz cultivar produced more spikes per m2 (502.42) than Atila cultivar (448.53). However, there was no significant difference within different split rates of N on spike number per m2 which was probably related to rate of tiller production. The obtained results of this experiment showed that cultivar affected spike number per m2, grain number in spike and thousands grain weight in first year of experiment, whereas grain number in spike only was different in second year. There were significant main and interactive effects of cultivar and N spliting on grain yield, biological yield and harvest index. Maximum yield was obtained with N5 treatment (568.4 g/m2) and minimum yield was obtained by N5 treatment (542.33 g/m2). Considering of 26.7 kg/ m2 difference between treatments which would be beneficial to farmers. N spliting did not significantly affect yield, but split rate of N application in two growth stages (%50 at planting time and %50 at stem elongation) could be desirable for farmers.

To deliver water from a large diameter irrigation pipeline to a smaller diameter plastic gated pipe so called "Hydroflume", a pipe turnout was designed, built and installed in the farms of the Sugar Cane Development and By-products Company, Ahwaz, Iran. In this paper the hydraulic performance of these pipe turnouts along a low pressure irrigation pipeline and their sensitivity against variation of hydraulic gradient, which caused by opening and closing other turnouts, was calculated by a computer model which developed by the author. Calculations by this computer model show that the discharge of all turnouts are varied by opening or closing any of the turnouts along the pipeline, but these variations are not equal for all operating turnouts. The turnouts which located at the end of pipeline are the most sensitive to the hydraulic gradient variation which may be about 5 percent. The procedure for sensitivity calculation and results are presented in this paper.

During 1998-99 growing season the present study was conducted to isolate and identify Fusarium species from root and crown of wheat and barley in Khuzestan province. So, infected plants were collected from different locations including: Andimeshk, Ahwaz, Izeh, Hamidieh, Khoramshahr, Dezful, Susangerd, Shadegan, Shavour, Shush, Shushtar, Abd-el-Khan, Mahshahr, Mollasani, Hafttape, and Hoveizeh. Fungal isolation was made by plating surface sterilized segments of rotted root and crown of plants on PDA and Nash & Snyder media. One hundred and three isolates of Fusarium were isolated. Among fungal isolates, 12 species were identified as follows: F. semitectum, F. solani, F. proliferatum, F. subglutinans, F. oxysporum, F. moniliforme, F. equisei, F. longipes, F. lateritium, F. sambucinum, F. diversisporum and F. anthophilum. Among species, F.semitectum was the most frequent (23.3%) and isolated from both plants in the most areas, and F. anthophilum was the least frequent (0.97%) and isolated from wheat only in Shadegan. It seems that, this is the first repot of occurrence of F. longipes and F.diversisporum on roots-and crowns of wheat and barley and F. anthophilum on the wheat crown in the world. Also, occurrence of F. lateritium, F. solani and F. subglutinans on the barley is new for Iran.