Two field trials were conducted during 1986 and 1987 seasons to study the response of three soybean varieties (Crowford, Elgen and Keller) to foliar spray with four nutrient compounds (Foliar X, Iral agromy, Fetrilon combi and X 250). For all tested soybean varieties, plant height, number and area of leaves/ plant, the dry weight of different plant parts as number of pods per plant and the final seed yield, were significantly increased by foliar spraying with all nutrient compounds, compared with the control.

Forty-nine varieties of sweet potato were analysed for their nutrient content, energy content and antinutrient composition.

A nutrient solution-sand culture study was conducted in a greenhouse to evaluate the response of 35 soft red winter wheat varieties to S. Wheat seedlings were grown for 35 days in sand that was leached every other day with complete nutrient solution containing 0, 1 or 5 mg S04-S L-1. Herbage yield of 5-week-old wheat plants was increased an average of fourfold as the level of S in solution was increased from 0 to 5 mg L-1. The concentration of S in the herbage was increased an average of three-fold as the concentration of S was increased from 0 to 5 mg L-1. Differences were observed among varieties for both dry matter and the concentration of S in plant tissue. However, differences among varieties were not consistent at all three levels of S in solution. Sulfur concentration in wheat herbage explained only 24% of the variability in wheat herbage yield. The study did allow for a general grouping of varieties giving the highest, lowest and intermediate yields. Concentrations of Mg, Cu, P, Fe, Mn and Zn were also affected by the level of S04-S.

Three rhizobia strains from groundnut (GN), chickpea (CP) and soybean (SB) were maintained in peat media. Eight treatments constituted of 2 cowpea varieties and 3 rhizobial strains (GN, CP and SB) with a control (non-inoculated). Control plants were supplied with 18 ppm N-containing nutrient solution, whereas inoculated plants were supplied with nutrient solution (without N) every day. Nodulation study conducted at 30 days after emergence (DAE) identified that up to 10.0 and 4.8 times increased nodulation against the control (-IN) occurred by var. SSD625 and IT82E60 respectively. Nodulation by CP and SB treatments did not differ significantly from the control. Nodule dry weight showed increasing tendency by all inoculum and both varieties. GN inoculation had significantly highest nodule dry weight (464 and 456% increase by SSD625 and IT82E60 respectively) as compared to the control. Nitrogenase activity of nodule bacteria measured by Gas Chromatograph showed that the highest activity was performed by GN inoculum in both varieties. The activity increment rate was highest at 30 DAE for GN inoculum. By GN and CP inoculum treatment the nitrogenase activity decreased after 60 DAE, but SB inoculation showed and increasing tendency at this stage.

Differences among rice varieties caused by aluminum toxicity especially on root length were clearly observed in seedling aged 14 days after sowing in solution containing 25-50 ppm Al3+. Seedlings of 100 rice varieties were evaluated by their aluminum tolerance in nutrient solution of 0 and 30 ppm Al3+. Relative root length was then used as criterion of aluminum tolerance. Aluminum tolerance of 100 varieties was not related to acid sulfate soil tolerance in cases of absolute growth and yield, relative growth, relative yield and yield components. Aluminum tolerance of photoperiod-sensitive varieties was related to acid sulfate soil tolerance in cases of relative root length and relative tillering. Twenty two varieties were tolerant to acid sulfate soil. Where 5, 12, 5 of those were classified as tolerant, intermediate and susceptible to aluminum, respectively. Aluminum tolerance of selected acid sulfate soil tolerant varieties which were subjected to replicated yield trial in acid sulfate soil Rangsit series was not significantly related to yield and yield components. Because of less amount of aluminum in the acid sulfate soil, aluminum was therefore not a major rice growth inhibiting factor in these soils. Result of the relationship between aluminum tolerance in solution culture and acid sulfate soil tolerance of tested 100 rice varieties was not significant.

The behaviour of the two barley varieties Aramir and Diva to increasing salinity in root sphere was studied in short-term experiments under controlled conditions. Treatments consisted in three concentration levels of 25, 50 and 100 meg/1 kcal and NaCl resp. and two ratios of K to Na 9:1 and 1:9 at each level. The germination of the two varieties varied with salt concentration and it was lower for Aramir than for Diva at all treatments. Salt concentrations in the nutrient solution higher than 25 meq/1 with the ratio 1:9 of K to Na reduced growth and dry matter yield of both varieties. Changes in the appearance of plants were observed as chlorosis and toxicity symptoms as necrosis of the tip of the leaves. The resistance of both varieties to increase of salinity as KCl was higher than NaCl. In general Aramir was more resistant to the increase in NaCl while Diva could obviously better tolerate increasing KCl concentration. Considering the response of both varieties in terms of maximum biomass production to the different levels of salt concentration expressed as EC evidently the two varieties have a degree of salt resistance as to tolerate a medium to strong salinity referring to the practiced growth conditions

Proportionate mass distribution of dry matter in shoot and root and phosphorus concentration and content of five varieties of each C. capsularis and C. olitorius jute at different development stage were measured. The variety JRC-321 showed the highest percentage of dry matter accumulation (72%), concentration (1.13%) and content (80.9%) of phosphorus in shoot and root at 105 days of growth. In the pattern of P absorption (shoot+root), the major share i.e. 54-81 percent of P was found during the growth period of 75-105 days in casularis varieties and 48-68 percent in olitorius varieties of jute. The pattern of DM accumulation and P absorption during the growth period leave a scope to think about the management decision relative to timing of P application to avaid any occurence of P nutrient deficiency likely, will require a fertilizer application in advance of the critical period.

In order to obtain basic information for breeding varieties of forage rape which is suitable at the southern part of Korea, seventeen introduced varieties were grown from Sep. 1986 to May 1987 at Mokpo Branch Station, Crop Experiment Station, and yield components and nutrient quality of plants were observed. Forage rape cv. Verox showed higher dry matter yield than any other variety used in the experiment. It showed relatively high content of crude protein and in vitro dry matter digestibility (IVDMD) and low content of NDF, ADF, cellulose and lignin. Therefore, it was concluded that Velox was the most suitable variety with high yield and high nutrient quality at the southern part of Korea. The heritabilities of all the observed characters but hemicellulose were estimated to be large. Total dry matter yield showed highly significant positive correlations with plant length, stem diameter, number of main stem leaves, fresh yield, stem dry matter yield, leaf dry matter yield, in vitro dry matter digestibility (IVDMD) and digestible dry matter yield (DDMY). These characters mentioned above showed negative correlations with content of NDF, ADF, cellulose and lignin. According to the result of path coefficient analysis, characters highly correlated with total dry matter yield showed large direct effects on total dry matter yield

Quality and mineral content of fruit from internal tree canopies were compared with those from external canopy positions in 4 citrus varities: 'Kinnow' mandarin; 'Redblush' grapefruit; 'Valencia' orange; and 'Lisbon' lemon. Fruit weight, total juice per fruit, peel fresh and dry weight, and rind thickness of fruit from internal canopies of all 4 varieties were significantly higher compared with external fruit. Mandarin, grapefruit, and orange fruit from external canopies had higher soluble solids and specific gravity. Fruit from internal canopies of all varieties had generally higher peel concentrations (% dry weight) of N, P and R due to a dilution effect, while the opposite condition existed in mandarin when these elements were expressed on a percent fresh weight basis. Peel Mg and S from external fruit were higher in all varieties, expressed as percentage of either dry weight or fresh weight. Nitrogen content of mandarin and orange juice and Ca content of grapefruit and lemon juice from external fruit were significantly higher compared to those from internal canopy fruit. Elimination of fruit quality and mineral variations as a result of canopy positions in recommended by the means of cultural practices.