The effect of varying levels of leaf defoliation on the nodulation and nitrogen fuation of a Virginia and a spanish-type peanut (Arachis hypogaea L.) cultivar was investigated in the greenhouse. Five leaf defoliation treatments -(a) control (no leaflet removal), (b) 25%, (c) 50%, (d) 7596, and (e) 100% -were carried out every 3 to 5 days throughout the growing period.All nitrogen fixation measurements were af€ected by the defoliation (leaflet removal) treatments. Increased leaf defoliation reduced nodule formation and N2 fixation. The reduction in plant dry weight, nodule number, nodule dry weight, and nitrogenase activity was most severe for the 100% defoliation treatment. Correlation coefficients (r) of N2 fixation measurements and leaf areas and weights were highly significant.The defoliation effect was similar in both experiments and cultivars; however, the Virginia type achieved higher values for all N2 fuation measurements.Key Words: Arachis hypogaea, nodulation, defoliation, leaf area.Nitrogen fixation influences the yield and quality of leguminous plants. Compatible bacteria and hosts can initiate nodulations, but adequate energy supplies are required for nodule growth and sustained nodule hnction. Carbohydrates are translocated from their source to nodules to support respiration and growth and to supply energy for N2 fixation.Schubert and Ryle (9) stated that N2 fixation in legume nodules is an energy-intensive process and may utilize between 10 and 30% of the total net photosynthate produced by the host plant. Shulyndin (10) Hardy and Havelka (6) stated that factors that decrease the amount of photosynthate available to the nodule decrease N, fmation. Decreased light intensity, decreased photosynthate due to partial defoliation, high planting density and lodging, increased demand of competitive sinks during late seed development, and cessation of translocation to nodules by girdling all reduced N2 fixation. Factors that increase the amount of photosynthate available to the nodule increased N fixation; for example, increased light intensity, increased source size by graft- ing additional foliage and low plant density, decreased demand of competitive sinks through pod removal, and increased photosynthesis by CO, enrichment of the foliar canopy.Because the leaf is the basic photosynthetic organ and is the major source of photosynthetic assimilates to the nodules, studies have been conducted to investigate the effect of defoliation on nitrogen fixation in some legumes. The effect of severe defoliation was reported by Brun (2) in soybean. He found that partial defoliation of soybean plants after flowering reduced N, fixation from 125 to 100 kg Nha.Information is lacking on the effects of leaf defoliation on N, fixation in peanut (Arachis hypogaea L.). This study was designed to determine the effect of leafdefoliation on nodulation and nitrogen fixation. Materials and MethodsTwo peanut cultivars, NC 7 (Virginia type, ssp. hypogaea var. hypogaea) and Argentine (Spanish type, ssp. fstigiata var. vulga...

The urinary free amino acid pattern in a morning urine sample of Sudanese children suffering from Kwashiorkor and marasmus were determined before and during the course of treatment up to the 2nd week. The urinary amino acid/total urinary N (3.62) was found to be almost constant for Kwashiorkor patients, while the mean for marasmic patients was found to be 27. The concentration of leucine, valine, phenylalanine, methylhistidine, lysine, hydroxylysine and beta-amino-isobutyric acid was elevated in marasmic children, while the concentration of most of these amino acids was at a lower level in Kwashiorkor patients. The significance of these differences was discussed in relation to the biochemical detection of these deficiencies in field nutrition surveys.

S U M M A R YA field study was conducted on vertisols to determine the effect of three watering regimes and two plant densities on growth and yield of groundnuts. Total water requirements ranged from 486 to 597 mm depending on treatments. Three quarters of the water depletion was from the upper 20-30 cm. Plants in the sparse population were more sensitive to water stress so that the watering interval could be lengthened in the dense population without seriously reducing yield.

Field survey was conducted during the summer season of 2011-2012 to determine the weed flora and weed dominance at the irrigated sites of White Nile State. The State was divided into six irrigated sites from which a total of thirty-five fields were selected and ten quadrates (1m 2 ) from each field were taken randomly. In each quadrate individual weed species were recorded. Field frequency, uniformity and mean field density were also determined for each weed. Fifty five weed species belonging to twenty-four families (three monocotyledonous and twenty-one dicotyledonous) were recorded. The AI which used as weed survey method is to evaluate the weed management strategies and the change of weed species in weed communities through years.

This study conducted during the season 2017 at ED-Duem Locality which is laid at Northern White Nile State of Sudan, the main objectives of this study was measurement, listing of all acacia raddiana tree sites their assessed the physical characteristics of the height, diameter at breast height and were account the abundance, dominance, and survival % of natural regeneration of acacia raddiana tree as the main species. The researcher used the systematic circular sampling plots methodology which established with total number of 130 sample plots. The sample plots were circular in shape with a radius of 17.84 m (0.1 ha in area.). In these sample plots all trees with diameter at breast height (dbh) equal to or greater than seven centimeters were measured for tree species, and the regeneration survey in each sample plot (10) quadrats (subplots) of 1mx1m (1m²), the regeneration survey in each sample plot (10) quadrats (subplots) of 1mx1m (1m²) were calculated. The results showed no signifi cant different for acacia raddiana tree in eight sites, and the survival rate of Acacia raddiana regeneration are (20.4-23.9%).