Melon plants grafted on Cucurbita rootstock may suffer from nutritional deficiencies due to reduced absorption and translocation of minerals to the foliage. Melon (Cucumis melo L.) cv. 6023 was grafted onto two interspecific Cucurbita rootstocks (Cucurbita maxima × Cucurbita moschata) ‘TZ-148’ and ‘Gad’. Nongrafted melons were used as controls. Two fertilization field experiments were conducted in walk-in tunnels in the northern Arava valley of southern Israel. Two fertigation regimes were used: 1) standard and 2) enriched for magnesium (Mg; 150 mg·L−1), manganese (Mn; 7.5 mg·L−1), and zinc (Zn; 0.75 mg·L−1) to increase the concentrations of the lacking elements. The enriched fertigation significantly increased Mn, Zn, and Mg contents in the leaf tissue. Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), chloride (Cl), iron (Fe), and boron (B) were unaffected by the enriched fertilizer. There were no deficiency symptoms in grafted plants supplied with the enriched fertilizer.
Menahem Edelstein, Roni Cohen, Meital Elkabetz, Shimon Pivonia, Ami Maduel, Tom Sadeh-Yarok and M. Ben-Hur
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.
S.M. Southwick, W. Olson, J. Yeager and K.G. Weis
During the fruit growing season, April through August 1990, 1991, and 1992, four sprays of 20-22 liters/tree of KNO3 were applied to `French' prune trees (Prunus domestica L. syn. `Petite d'Agen). Spray applications of KNO3 were compared to single annual soil applications of KCl (1.4-2.3 kg/tree) and sprays of urea + KNO3 with respect to leaf K and N, fruit size, drying ratio, and dry yield. Potassium nitrate sprays were as effective, or better, than soil-applied K in maintaining adequate levels of leaf K throughout the season. Treatment effects were not carried over into the next year. Lowest leaf K was found in trees where no K had been applied. Those values were below the adequate level of 1.3% K and the untreated group developed K deficiency symptoms. Consistent effects on leaf K were not obtained when urea was applied and no negative effect on leaf K was demonstrated. Equivalent dry yields per tree were obtained by foliar and soil K applications. There was no best time for KNO3 sprays. Yield per tree was not enhanced when foliar K-N sprays were applied to trees that had levels of 1.3% K or more as of 15 Apr. 1992. Trees that were below optimum K in April tended toward improved dry yields after four K-N sprays. Trees that had no applied K were lowest yielding. Drying ratios and fruit size (number of fruit per kilogram) were not different among K treatments. Dry yields per tree were increased without a decrease in fruit size or an increase in drying ratio with either soil or foliar K application. These results suggest that foliar KNO3 sprays applied four times throughout the growing season can be used to correct incipient K deficiency in `French' prune and to obtain dry yields equivalent to those obtained with soil applications of KCl.
Brígida Resende Almeida, Suzan Kelly Vilela Bertolucci, Alexandre Alves de Carvalho, Heitor Luiz Heiderich Roza, Felipe Campos Figueiredo and José Eduardo Brasil Pereira Pinto
The effect of macronutrient omission on the growth and volatile chemical composition of Lippia gracilis was evaluated. The “minus one element” technique was employed by using a complete (Hoagland and Arnon, 1950) nutrient solution and solutions with macronutrient omission for N, P, K, Ca, Mg, and S. Macronutrient deficiency significantly influenced L. gracilis growth and volatile chemical composition. Leaf dry weight decreased in order of importance of the macronutrients as follows: Ca = K = N > P > Mg > S. The amount and composition of volatile compounds varied according to macronutrient omission. The major constituents were characterized by p-cymene (ranging from not detected to 43.41%), thymol (3.86% to 7.95%), carvacrol (44.09% to 76.69%), and caryophyllene (0.52% to 6.00%), the contents of which were dependent on the omitted macronutrient. Lack of Ca, Mg, and S increased the contents of cymene and decreased the thymol and carvacrol compared with control. Complete solution and N, P, and K omission retained the same thymol and carvacrol content. In summary, macronutrient availability effectively controlled plant growth and volatile chemical composition of L. gracilis.
M. Teresa Gómez-Casero, Francisca López-Granados, José M. Peña-Barragán, Montserrat Jurado-Expósito, Luis García-Torres and Ricardo Fernández-Escobar
the sufficiency threshold of 1.5%, except for SF treatments in 2004, for which the leaf N concentration was 1.64%. These olive trees were under nutritional deficiency, indicating that they would not reach an optimum level of productivity as previously
Timothy K. Broschat
landscapes, palms are rarely seen without at least one nutrient deficiency. Because landscape palms are grown almost exclusively for aesthetic purposes and their leaves are very large, nutritional deficiencies are conspicuous and unattractive. Also
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
fundamental to the use of this method of plant nutritional evaluation. Thus, the cultivation of plants in protected systems using culture medium is an essential tool for plant nutrition studies, especially those that induce nutritional deficiency ( Prado, 2008
Alfonso José Lag-Brotons, José Martín Soriano-Disla, Ignacio Gómez and José Navarro-Pedreño
growth reduction, no visual symptoms of nutritional deficiencies were observed. Table 4. Cardoon morphological parameters at the end of the experiment (mean values ± sd , n = 3). The mineral composition of cynara tissues and the effects of saline
C.A. Sanchez, G.H. Snyder and H.W. Burdine
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.
Renuka Rao and Yuncong Li
The review of effects of excessive soil water on performance of various vegetable crops and selected field crops indicates that in areas where temporary flooding hazards are expected during the growing season, crops can be selected on their relative ability to tolerate excessive moisture. Field crops are generally less sensitive than vegetable crops in terms of yield. In addition to the choice of crop species, planting dates could be shifted when possible by delaying dates of sowing or planting to avoid probable periods of flooding during the sensitive growth stages. In most instances, crops are more sensitive at their early developmental phase than at the later stages in terms of yield. Soil management practices like ridging and furrowing or making raised beds before planting is recommended. In addition, amelioration with foliar application of chemicals like nutrients, growth hormones and fungicides is also recommended to overcome nutritional deficiencies, hormonal imbalances and disease infections. Every effort of amelioration should be exerted at the earliest opportunity, since water damage to crops becomes more severe with longer flooding duration.