Guzmania lingulata (L.) Mez. ‘Cherry’ plants were grown in coconut husk chips. All plants were given 8 mm nitrogen (N), 2 mm phosphorus (P), 4 mm calcium (Ca), and 1 mm magnesium (Mg) at each irrigation with potassium (K) concentration at 0, 2, 4, or 6 mm. After 9 months, K concentration did not alter the number of new leaves, and shoot and root dry weights. Increasing K concentration did not affect the length but increased the width of the most recently fully expanded leaves (the sixth leaves). Plants under 0 K exhibited yellow spots and irregular chlorosis on old leaves being more severe at the middle of the blade and leaf tip. Numbers of leaves with yellow spots or chlorosis decreased with increasing K concentration. Chlorenchyma thickness was unaffected by K concentration, whereas water storage tissue and total leaf thickness increased with increasing K concentration. Leaf N concentration in the sixth or 10th leaf was unaffected by solution K concentration. However, plants at 0 mm K had higher N concentration in the 14th leaf than those in sixth and 10th leaves. Leaf P, Ca, and Mg concentrations decreased with increasing solution K concentration. K concentrations were higher in the sixth leaf than the 14th leaf in plants at 0, 2, or 4 mm K, whereas leaf K concentration was 15 g·kg−1 on dry weight basis in the sixth, 10th, or 14th leaves in plants treated with 6 mm K.
Chao-Yi Lin and Der-Ming Yeh
D.S. Achor and L.G. Albrigo
Permanent chlorosis of leaves on plants fertilized with urea containing high levels of the contaminant biuret has been observed in several crops including citrus. Little has been reported as to the cellular changes that result from such chlorosis. Branches from `Ruby Red' grapefruit (Citrus paradisi Macfadyn) and `Hamlin' orange [C. sinensis (L.) Osbeck] were sprayed with urea solutions containing 1.05% biuret. As visible symptoms developed, leaf tissue samples were prepared for transmission electron microscopy. For comparison purposes, leaves from similar trees showing chlorosis from age-related senescence and Zn deficiency were also sampled. The progressive development of chlorosis in biuret-affected leaves was characterized by: the loss of starch, thylakoidal and granal membranes in chloroplasts along with the enlargement and increase in number of plastoglobuli or lipid bodies. The lipid bodies were liberated alone or in association with membrane vesicles to the cytoplasm and vacuoles. The number and volume of the individual chloroplasts became smaller. Concurrent loss of cytoplasmic content and the enlargement of the vacuolar space were also observed in the biuret affected leaf tissue. Similar findings were observed in the cells of senescent leaves. In cells of leaves showing nutritional deficiency, losses in cytoplasmic content and vacuolar enlargement were observed but there was neither complete loss of thylakoidal or granal membranes nor the release of lipids from the plastids. It was concluded that 1) the cytological characteristics of the biuret-affected samples were more similar to age-related senescent samples than to chlorosis from Zn deficiency and 2) that complete loss of the lipid bodies from the chromoplasts to the cytoplasm and vacuole in the biuret-affected samples and in age-related senescence in citrus leaves was responsible for the permanent nature of the chlorosis.
Bare-root, vegetatively propagated plants (average 15-cm leaf spread) of a white-flowered Phalaenopsis Taisuco Kochdian clone were imported in late May and planted either in a mix consisting of three parts medium-grade douglas fir bark and one part each of perlite and coarse canadian sphagnum peat (by volume) or in chilean sphagnum moss. All plants were given 200 mg·L−1 each of nitrogen and phosphorus, 100 mg·L−1 calcium, and 50 mg·L−1 magnesium at each irrigation with 0, 50, 100, 200, 300, 400, or 500 mg·L−1 potassium (K). After 8 months, K concentration did not alter the number of new leaves on plants in either medium. Plants grown in moss produced four to five leaves, whereas those planted in the bark mix produced only two to three leaves. K concentration did not affect the length of the uppermost mature leaves when grown in the bark mix. However, in moss, plants had increasingly longer and wider top leaves as K concentration increased. The lower leaves on plants in the bark mix lacking or receiving 50 mg·L−1 K showed symptoms of yellowing, irregular purple spots, and necrosis after spiking and flowering, respectively. Yellowing and necrosis started from the leaf tip or margin and progressed basipetally. Symptoms became more severe during flower stem development and flowering. All of the plants lacking K were dead by the end of flowering. Leaf death originated from the lowest leaf and advanced to the upper leaves. K at 50 mg·L−1 greatly reduced and 100 mg·L−1 completely alleviated the symptoms of K deficiency at the time of flowering. However, by the end of flowering, plants receiving 50 or 100 mg·L−1 K had yellowing on one or two lower leaves. Plants grown in moss and lacking K showed limited signs of K deficiency. All plants in the bark mix bloomed, whereas none in sphagnum moss receiving 0 mg·L−1 K produced flowers. For both media, as K concentration increased, flower count and diameter increased. Flower stems on plants in either medium became longer and thicker with increasing K concentration. To obtain top-quality Phalaenopsis with the greatest leaf length, highest flower count, largest flowers, and longest inflorescences, it is recommended that 300 mg·L−1 K be applied under high N and high P conditions regardless of the medium.
Silver Tumwegamire, Regina Kapinga, Patrick R. Rubaihayo, Don R. LaBonte, Wolfgang J. Grüneberg, Gabriela Burgos, Thomas zum Felde, Rosemary Carpio, Elke Pawelzik, and Robert O.M. Mwanga
potential contributions of the accessions to alleviate vitamin A and mineral deficiencies in the EA region. Materials and Methods Ninety sweetpotato accessions were used in this study ( Table 1 ). All varieties were farmer varieties from EA, except the
James P. Gilreath, Carlene A. Chase, and Salvadore J. Locascio
Glyphosate at sublethal rates was applied prebloom, at-bloom, or postbloom relative to the first flower cluster to tomato (Lycopersicon esculentum Mill.) to determine the effect on foliar concentrations of N, P, K, Ca, and Mg. Glyphosate rates of 0, 1, 6, 10, 60, and 100 g·ha-1 were used to simulate the effects of spray drift. In three studies, plant vigor declined with increased glyphosate rates and younger plants were more sensitive than older plants. Plant height decreased as glyphosate rate increased, but the response differed with time of evaluation and with stage of development. In Expt. 1, N content decreased with increasing rate of glyphosate, regardless of stage of development, but response varied with time of evaluation with prebloom and at-bloom applications. In Expt. 2, prebloom glyphosate applications reduced N content, but applications at-bloom did not. P declined with prebloom and at-bloom glyphosate applications in Expt. 1, but only with prebloom applications in Expt. 2. In Expt. 3, P concentrations generally declined with glyphosate rates ≤10 g·ha-1, but were unchanged or increased with rates of 60 and 100 g·ha-1. Tissue K, Ca, and Mg concentrations were not consistently affected by glyphosate rate and sample times. Although significant changes in foliar concentrations of N, P, K, Ca, and Mg occurred, leaf mineral analysis was not considered to be a reliable method of quantifying sublethal effects of glyphosate in tomato. Mineral deficiency did not occur in response to glyphosate application. Chemical name used: N-(phosphonomethyl)glycine (glyphosate).
Allen V. Barker
covers mineral deficiencies and toxicities. Attention is given to iron deficiency in alkaline soils, phosphorus uptake in low-phosphorus soils, aluminum toxicity and tolerance in acid soils, and toxicity and tolerance to essential and nonessential
Giuseppe Cimò, Riccardo Lo Bianco, Pedro Gonzalez, Wije Bandaranayake, Edgardo Etxeberria, and James P. Syvertsen
( Etxeberria et al., 2009 ). At later stages, leaves become small and upright, common drought stress-like symptoms. Leaves can also develop a variety of chlorotic patterns that often resemble mineral deficiencies such as those of zinc, iron, and manganese
María José Jiménez-Moreno and Ricardo Fernández-Escobar
, Rutgers University, NJ Hartmann, H.T. Brown, J.G. 1953 The effect of certain mineral deficiencies on the growth, leaf appearance, and mineral content of young olive trees Hilgardia 22 3 119 130 Holford, I.C.R. 1997 Soil phosphorus: Its measurements and its
Laban K. Rutto, Myong-Sook Ansari, and Michael Brandt
to internal nutrient dilution if later stages of growth are characterized by mineral deficiency. Specific to stinging nettle, Dambroth and Seehuber (1988) report that high N fertilization could have a negative effect on the quality of stinging
Carlos Henrique Oliveira de David, Vespasiano Borges de Paiva Neto, Cid Naudi Silva Campos, Priscilla Maria da Silva Liber Lopes, Paulo Eduardo Teodoro, and Renato de Mello Prado
, mineral deficiency symptoms present particular inter- and intraspecies responses as a result of gene expression and environmental factors ( Hawkesford et al., 2012 ). The knowledge of the symptomatology caused by the deficiency of a specific nutrient is