Abstract
Minerals are constant constituents of animal tissue. They may be essential components for the maintenance of life processes, or they may perform some nonessential but favorable function. Man is omniverous and can live on a diet of animal, vegetable or mineral origin. The sources of minerals are therefore immaterial for man and the other omnivora; but the presence of all these elements in our food supply is essential. All essential elements are beneficial when present in the body in proper balance. Out of balance or in deficiency they lead to diseases and in excess they may be toxic. Various mineral elements are so interrelated in metabolism that their quantitative requirements are interdependent. A deficiency of a given nutrient may exist with respect to its specific function and also in the balance which should be maintained between it and certain other essentials. Conversely, pathological changes may result from relative as well as from absolute excesses of a given element.
During forcing, the witloof chicory taproot produces an etiolated bud, the chicon. The axis of this organ often is brown as a consequence of a disorder associated with a localized Ca deficiency. The effect of the main anions (NO3 -, Cl-, SO4 2) in the nutrient solution on Ca (45Ca) absorption and translocation in the chicon was investigated. Although the amount of Ca that accumulated in the chicon was not affected by nutrient solution composition, Ca (45Ca) mobility was modified. The amount of radioactivity in the chicon increased slightly when the main anion in the solution was sulfate and decreased markedly when the main anion was chloride, compared to nitrate. Calculations of the specific radioactivity of Ca reaching the chicon and in root tissue suggest that, when slowed down, Ca transport consists of a homogeneous flow in all root tissues, whereas, in other cases, Ca moves along a preferential pathway, such as the xylem vessels. Modifying the anionic composition of the nutrient solution to avoid a localized Ca deficiency is discussed.
Rooted cuttings of Nemaguard peach (Prunus persica (L.) Batsch.) were grown in 0.18, 0.36, 0.90, and 2.40 liter containers for 16 weeks to study the influence of root confinement on growth, gas exchange, water uptake, and leaf carbohydrate and nutrient content. Leaf area and stem length were reduced by root confinement beginning 6-7 weeks after transplanting, and differences among treatments increased through week 16. Final tree dry weights were reduced 51% over a 13-fold change in rooting volume, but dry weight partitioning was largely unaffected. Consistent reductions in CO2 assimilation and leaf conductance for confined trees did not occur until after week 11. Sorbitol and starch accumulated earlier in leaves of trees in smaller containers, but sorbitol was reduced and starch was unaffected by container volume at week 16. Despite similar soil fertility, leaf nutrient concentrations were reduced —two-fold by root confinement, except N (reduced 38%), yet characteristic deficiency symptoms were not observed. Initial mechanism(s) limiting growth were not gas exchange rates, levels of nonstructural carbohydrates, or drought stress, although nutrient deficiency cannot be ruled out as a factor limiting growth of trees with restricted rooting volume.
After 10 years, application of 112 kg N/ha, divided into four annual applications and applied through the drip irrigation system (fertigated), provided nut yield and quality as good as 224 kg·ha–1 all broadcast or 1/2 fertigated and 1/2 broadcast. Leaf N was well above the 2.50% deficiency threshold. Treatment rates were halved for six additional years with no detrimental effects on yield and quality from fertigation. All treatments still provided leaf N well above the deficiency threshold. After 16 years of N fertigation there appears to be no serious reduction of pH or flushing of other nutrients from the wetted zone of the emitter. Leaf and soil analysis indicate a loss of Ca and Mg in the area away from the emitter when N was broadcast. Soil pH and nutrients were lower in the wetted zone of the emitter than in the area not wet by the emitter, and soil pH, K, and Mg were reduced in the 15- to 30-cm layer with fertigation. Leaf nutrient concentrations reflected the cation concentrations in the nonwetted area. Broadcast N was from NH4NO3 and fertigated N was from URAN (16% N from NH4NO3 and 16% N from urea).
Most deciduous fruit crops in Italy are grown in the north and especially in the eastern part of the Po River Valley (mainly in the Emilia Romagna and Veneto regions) and in the Adige River Valley (South Tyrol and Trento provinces). Soils in the wide Po River Valley, where pear (Pyrus communis), peach and nectarine (Prunus persica), kiwifruit (Actinidia deliciosa), plum (Prunus domestica and P. insititia), apricot (Prunus armeniaca), cherry (Prunus avium), and apple (Malus domestica) are grown, are alluvial, generally fertile, fine textured, alkaline, often calcareous and well enriched with Ca. Apple plantings are concentrated in the Adige Valley and located on a variety of soil types, including sandy loam, loamy sand soils or sandy clay, sometimes calcareous. Integrated fruit production is gaining importance and represents more than 80% of apple production in South Tyrol and about 60% of peach and nectarine production in Emilia Romagna. Under these conditions, the main objectives of mineral nutrition are to reconcile production and environmental concerns (minimize nutrient leaching, soil pollution, volatile emissions). In particular, fertilization aims to improve external and internal fruit quality and storage ability, reduce production costs, maintain soil fertility, avoid nutrient deficiency and excess and control tree vigor. Nitrogen applications have strongly decreased in recent years and there is a need to improve the efficiency of N fertilizers while avoiding deficiencies. Research is focussing on application technology, timing of N uptake, internal cycling of N and methods for assessing the need for N application (e.g., using estimates of native soil N availability). Early diagnosis of bitter pit is recommended for guiding applications of Ca sprays. Iron deficiency and chlorosis is a major problem in pear, peach and kiwifruit grown in alkaline and calcareous soils and Fe chelates are usually applied annually to the soil or to the canopy. Current research is focused on agronomic means for controlling the problem and on developing rootstocks tolerant to Fe deficiency.
A decline in tissue nutrient concentration was observed in petunia and poinsettia during the first phase of root development ( Santos, 2009 ; Svenson and Davies, 1995 ). Nutrient applications during this phase have the potential to alleviate
Crop logging is a useful tool to keep track of the nutrient status of fruit trees. Crop logging can help extension personnel and farmers diagnose possible nutrient deficiency or toxicity problems and schedule fertilizer practices. A hypertext information system called “Tissue Analysis” was developed for crop logging of macadamia (Macadamia integrifolia Maiden and Betch) trees. The system runs on an Apple® Macintosh® computer using the software HyperCard® 2.0. It allows the user to keep track of the tissue analyses records of different farmers and their orchards and serves as a “front end” to link to the user's spreadsheet worksheets and charts of different nutrients. The user can create and maintain a list of farmers whereby a separate file is created for each farmer that then allows the user to create and maintain a list of the farmer's orchards. For each orchard, the user can name buttons according to different nutrients and set up linkages to spreadsheet worksheets and charts to view tissue analyses records. This information system can aid extension agents and farmers in monitoring the nutrient status of different orchards, diagnose possible nutritional problems, and schedule fertilizer applications.
Diagnosis and Recommendation Integrated System (DRIS) norms were derived for crisphead lettuce (Lactuca sativa L.) from field fertility experiments conducted over the past 20 years on mineral and organic soils in Florida. Preliminary testing indicates that DRIS diagnoses generally agree with diagnoses using the sufficiency range approach, with the advantage of predicting the degree of nutrient limitation. DRIS also appeared to correctly predict a response to K where sufficiency ranges currently used did not. Overall, DRIS appears to be a useful adjunct to the sufficiency range approach currently used to diagnose nutritional deficiencies in crisphead lettuce.
Abstract
‘Forever Yours’ roses (Rosa Hybrid Tea) were grown in recirculating nutrient solutions at 0.25, 2.5, 5.0 and 10.0 meq K/liter. Low K supply (0.25 and 2.5 meq/liter) reduced growth, flower production, and length of flowering stems. Leaf K concentration was reduced at the lowest K concentration in solution. Increasing K concentration in solution from 0.25 to 10.0 meq/liter had no antagonistic effect on the accumulation of Ca or Mg in the leaves. Plants which received 0.25 meq K/liter developed K deficiency symptoms after 5 weeks of growth in treatment solutions.
Abstract
Static solution culture systems are widely used in plant research and for teaching demonstrations of plant nutrient deficiency symptoms. Numerous systems have been described (1,2) including one (3) constructed of readily available materials. Reported here is another design for a static solution culture system built of readily available components. This system is characterized by a) low cost, b) simplicity, c) easy assembly, d) potential for variable spacing of culture vessels, e) identical aeration rate for each vessel without individual air flow valves, and f) aeration from the top of the culture vessel rather than the bottom, eliminating drainage through aeration lines should the air supply fail.