Evaluation of nutrient accumulation trends in fruit during fruit development and nutrient status in the leaves are important components defining nutrient requirements. Such nutrient demand should be met by nutrient supply in order to develop optimal rate and timing of fertilizer application. In a 3-year study the citrus (orange) varieties, 'Valencia', 'Parson Brown', 'Hamlin', and 'Sunburst' were fertilized with either 168, 224, or 280 kg N ha-1 yr-1 as a broadcast application of N:P:K dry soluble granular fertilizer. These rates did not significantly affect the fruit nutrient status, juice quality, or nutrients concentrations in the spring flush. The concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in the fruit decreased with their enlargement during June through November. However, micronutrient concentrations in the fruits increased from June through August or September and then decreased. Fruit dry weight was greatest in 'Valencia' followed by 'Hamlin', 'Parson Brown', and 'Sunburst' varieties. Soluble solids concentration (SSC) were higher in 'Valencia' and 'Sunburst' fruit than in the other two varieties. Other juice quality parameters were not significantly different among the varieties. This study indicated non-significant influence of fertilizer rates on concentrations of various mineral elements in 6-month-old spring flush with most of those concentrations within the optimal ranges.

An experiment was conducted at the Bangladesh Agricultural University, Mymensingh, in the rabi season (November to April) to study the effect of variety and planting arrangement on nutrition and nutrient uptake in maize. Four maize varieties-Barnali, Khoibhutta, Mohor and Shuvra were planted in two plating arrangements one plant per hill 25 cm apart (P1) and two plant per hill 50 cm apart (P2) in a constant row spacing of 75 cm. A split-plot design was used with three replications by placing variety in the main plot and planting arrangement in the sub plot. Results showed that both variety and planting arrangement had significant influence on nutrition and nutrient uptake in maize. Shuvra gave the highest grain yield (6.20 t ha-1) followed by Mohor (5.84 t ha- 1) and Barnali (5.59 t ha-1). Stalk yield was the highest (7.21 t ha-1) from Mohor. One plant per hill (P1) produced more grain and stalk yield (5.72 t ha-1 and 6.45 t ha-1, respectively) than P2 (5.41 ta/ha and 5.98 t ha-1 respectively). Nutrient content in grain differed significantly among the varieties but similar in both the planting arrangements (P1 and P2). In general, higher nutrient uptake by a variety appeared to correspond to its high grain yield. Planting arrangement also had influence on nutrient uptake. One plant per hill 25 cm apart caused more uptake than 2 plants per hill 50 cm apart. This study showed that the varieties Shurva and Mohor and one plant per hill 25 cm apart had higher nutrient uptake efficiency that resultant higher grain and stalk yield.

Root length and root-shoot ratio of two modern and two local varieties of rice increased significantly with decreasing strength of nutrient solution. Plant height and root length in rice is inversely related to increasing nutrient deficiency. The cation exchange capacity (CEC) of roots was significantly higher in sand: soil substratum with nutrient solution compared to liquid nutrient culture, indicating the importance of substratum for increasing exchange sites of ions. Root growth and CEC of roots are important physiological traits for selection of low nutrient requiring cultivars.

The selection of particular nutrient medium and optimal conditions of environment for growing shoot tips of walnut seedlings cvs. Sampion and Mire enabled successful micropropagation until the regeneration to a whole plant. The formation of the leaf rosettes of both walnut varieties was successful with all studied nutrient media while the propagation of shoots and rooting depended both on nutrient medium and walnut variety.

The effect of different growing media: peat and mixtures of peat and granulated, water repellent rockwool, 3:1 and 1:1, on growth of cyclamen (2 varieties) and poinsettia (3 varieties) was evaluated during two consecutive autumns. Poinsettia were grown as pinched or non-pinched plants. All plants were grown on ebb-and-flow benches and fertigated in each irrigation with nutrient solution based on complete fertilizers Peters 15:11:29 for cyclamen and Peters 15:5:25 for poinsettia. EC of nutrient solution for cyclamen was 1.2 and for poinsettia 1.8 mS/cm. Growth parameters of cyclamen were evaluated at full flowering and of poinsettia when the bracts were fully colored

Leaf chlorophyll content is closely related to leaf nitrogen (N) content, so it is reasonable to assume that ammonium-N (NH4-N): nitrate-N (NO3-N) ratio in the nutrient solution used to grow tomatoes (Lycopersicon esculentum Mill.) hydroponically may affect leaf greenness, and consequently chlorophyll meter (SPAD) readings. It has also been shown that increasing nutrient solution strength (NSS) increases tomato productivity, but there are no reports regarding how NSS affects SPAD readings under greenhouse conditions. Genotype may also influence SPAD readings, and standardization for cultivar and sampling time may be needed. The objective of this study was to characterize SPAD readings for five tomato cultivars and SPAD reading response to a combination of two NSS (1X and 4X Steiner solution strength daily applied 18 days after transplanting at 7 p.m.) and two concentration of NH4-N in solution (0 and 25%) in order to evaluate the potential of SPAD readings as a tomato yield predictor in greenhouse production systems. The SPAD readings were not uniform across tomato varieties tested, being consistently higher for 'Max' and lower for the other varieties. Initially, SPAD readings for tomato varieties used in this study were low at the vegetative stage, and increased up to 40 DAT, but subsequently decreased at 49 DAT, or the fruit set of the first and second clusters. After this time, SPAD readings showed no variation. Chlorophyll meter readings for 'Max' were higher in the top plant layers, but decreased in the top plant layer of the other tomato varieties. The SPAD readings were higher for plants supplied with 25% NH4-N than those without NH4-N in solution, but the use of a nighttime nutrient solution did not affect SPAD readings. None of the possible interactions among tomato variety, NH4-N:NO3-N ratio, and NSS were consistently significant.

An experiment was set up to determine the most important effect of the graperootstock-scion interaction in vineyard on the experimental plot of the University at the West edge of Lake Balaton. Three scion varieties were grafted on six rootstocks resulting in 18 combinations of graftings. All the development each of the graftings was examined and surveyed separately. Based on leaf analysis results we can gain data about the interaction of rootstock and scion varieties concerning mineral nutrition of the grafts, its differences and characteristics. In the present study we give account of leaves originated from vines grown same soil type and nutrient condition. Statistically significant differences were found in the yield production and Ca concentration of scion leaf blades according to the rootstocks as well according to the scions also. After the first yield production year the differences in K and Ca contents of the leaves were greater by the scion varieties than the rootstocks. The highest Ca concentrations were determined at the scion leaves with combination of Georgikon 28 ((V. berlandieri x V. riparia T. K. 5BB) x V. vinifera) rootstock. The differences in Ca concentrations were higher according to the scion varieties. It shows not only the rootstocks or the scions influences the nutrient supply of the vines, but the combinations of these two components is very important from this point of view.

Iron (Fe) toxicity is a major nutrient disorder affecting the production of wetland rice in the humid zone of West Africa. Little attention has been given to determining the macro- and micronutrient composition of rice plants grown on wetland soils where Fe toxicity is present although results from such study could provide useful information about the involvement of other nutrients in the occurrence of Fe toxicity. A field experiment was conducted in the 1997 dry season (January-May) at an Fe toxic site in Korhogo, Ivory Coast, to determine the elemental composition of Fe tolerant (CK 4) and susceptible (Bouake 189) lowland rice varieties without and with application of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). For both Fe-tolerant and susceptible varieties, there were no differences in elemental composition of the whole plant rice tops, sampled at 30 and 60 days after transplanting rice seedlings, except for Fe. All the other nutrient element concentrations were adequate. Both Fe-tolerant and susceptible cultivars had a high Fe content, well above the critical limit (300 mg Fe kg(-1) plant dry wt). These results along with our observations on the elemental composition of rice plant samples collected from several wetland swamp soils with Fe toxicity in West Africa suggest that "real" iron toxicity is a single nutrient (Fe) toxicity and not a multiple nutrient deficiency stress.

Iron (Fe) toxicity is a major nutrient disorder affecting the production of wetland rice in the humid zone of West Africa. Little attention has been given to determining the macro‐ and micronutrient composition of rice plants grown on wetland soils where Fe toxicity is present although results from such study could provide useful information about the involvement of other nutrients in the occurrence of Fe toxicity. A field experiment was conducted in the 1997 dry season (January‐May) at an Fe toxic site in Korhogo, Ivory Coast, to determine the elemental composition of Fe tolerant (CK 4) and susceptible (Bouake 189) lowland rice varieties without and with application of nitrogen (N), phosphorus (P), potassium (K), and zinc (Zn). For both Fe‐tolerant and susceptible varieties, there were no differences in elemental composition of the whole plant rice tops, sampled at 30 and 60 days after transplanting rice seedlings, except for Fe. All the other nutrient element concentrations were adequate. Both Fe‐tolerant and susceptible cultivars had a high Fe content, well above the critical limit (300 mg Fe kg‐1 plant dry wt). These results along with our observations on the elemental composition of rice plant samples collected from several wetland swamp soils with Fe toxicity in West Africa suggest that “real”; iron toxicity is a single nutrient (Fe) toxicity and not a multiple nutrient deficiency stress.

Nutrient concentration in consumed dry matter is the most actual problem of animal nutrition in the Czech Republic. Seven sequential samplings of 8 grass varieties (2 hybrids of Lolium multiflorum x Festuca arundinacea, Lolium perenne, 2 varieties of Lolium perenne, Festuca pratensis, Festuca arundinacea, Dactylis glomerata, Bromus uniloides) in weekly intervals during the 1st cutting period and samplings during the 2nd cutting period were realized in 1999 on two localities. Milk production was calculated from the energetic value of forage (NEL) during the vegetation period and expressed by means of kg FCM produced by a dairy cow consuming 13 kg of dry matter and requiring 3.13 MJ NEL per kg. The decrease of nutrient and energy concentrations in forage is associated with a lower productive efficiency of roughage. It is necessary to harvest grasses from May 20 to May 25 (1st cutting); the 2nd cutting should be realized until 45 days after the 1st cutting.