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Abstract
Kalanchoe blossfeldiana Poelln. ‘Feuerzauber’ plants were grown with sufficient and insufficient levels of N and Ca and differences in leaf concentrations of each nutrient between the sufficient and insufficient treatments (“differential”) were determined at various times between 5 and 14 weeks after planting and for a range of leaf positions. Largest N and Ca differentials generally occurred in the same leaves. In young plants, 5 to 7 weeks old, the largest differentials occurred in the young leaves immediately below the pinch. At 8 weeks the largest differentials were found in the young leaves on the lateral shoots. With increasing plant age the largest differentials were continually found in the younger leaves on lateral shoots. Throughout the 5 to 14 week period, leaves which had the largest consistent differentials were young developing leaves at least 2 cm wide and are deemed best suited for foliar analysis.
Abstract
Forcing azalea (Rhododendron sp. cvs. Redwing, Mission Bells and Gloria were subjected to sufficient and low levels of N, K, and Ca, and the difference in concentration of these nutrients was measured and termed “differential”. Immature, recently mature, and old leaves were sampled periodically from current shoots during development. Ca differential was not related to sample position. N differential was exhibited in a similar manner but was best expressed in older leaf tissue during late growth. The magnitude of the K differential was related to both sample position and sample date; the largest expression occurred in young leaf tissue during early growth and on older leaf tissue during late shoot development. The best single sample position for foliar analysis of these nutrients was the most recently mature leaves on current shoots.
Abstract
Symptoms for 7 nutrient deficiencies were established for elatior begonia ‘Schwabenland Red’ (Begonia X hiemalis Fotsch.). These are summarized in the form of a key as follows:
a. Chlorosis is a dominant symptom.
b. Chlorosis interveinal.
c. Interveinal chlorosis on older leaves followed by light tan necrotic spots within chlorotic areas which expand until leaf dies........................................................................................................................Mg
cc. Interveinal chlorosis on younger leaves.....................................................................................................Fe
bb. Chlorosis not interveinal.
c. Lower leaves uniformly yellow then purplish yellow and finally necrotic.................i.....................N
cc. Margins of canopy leaves yellow, then murky green-brown, and finally necrotic; all symptoms spread toward the leaf center......................................................................................................................Ca
aa. Chlorosis not a dominant symptom.
b. Necrosis begins along the margin of lower leaves and progresses inward....................................................K
bb. Plants stunted but normal green..........................................................................................................................P
bbb. Rust color, striations and cracks develop on young leaf petioles and peduncles perpendicular to their axes; internodes shortened and lateral shoots prolific; young leaves brittle crinkled around rust color spots which turn necrotic; chlorosis and necrosis spreading inward from the margin of young leaves...B
Abstract
Optimum N and K rates were established for ‘Schwabenland Red’ Rieger begonia for weekly fertilization and for application with each watering. Weekly application of 400 ppm N or more and 150 ppm or less resulted in undesirable plant size reduction regardless of K level; 200 ppm was marginal and 250 and 300 ppm N were best. Weekly applications of 60 to 200 ppm K were best and equal when applied with 250 ppm N while levels of 250 ppm K and greater caused smaller final plant size. The best rates of N for application with each watering were 100 and 150 ppm; 75 ppm and lower and 200 ppm and higher had deleterious effects. K levels from 50 to 125 ppm were best for application with every watering while levels of 150 ppm and greater were undesirable.
Abstract
Analysis of deficiency symptoms and foliar analyses of canopy leaves (youngest leaves 5 cm of wider) of Rieger elatior begonias (Begonia X hiemalis Fotsch cv. Schwabenland Red) indicated that the minimum critical levels for K, Mg, and B lie in the ranges of 0.93 to 0.95%, 0.22 to 0.25%, and 13.0 to 14.0 ppm, respectively.
Salinity guidelines for seed germination substrates call for low, difficult to attain levels. This study was conducted to determine the value of N, P, K, and S as preplant nutrients, with the anticipation that some could be eliminated to alleviate the high salinity problem in many substrates. Impatiens wallerana L. `Accent Rose' and Gomphrena globosa L. `Buddy' were tested in 288-cell plug trays containing a substrate of 3 sphagnum peat moss: 1 perlite (v/v) in two experiments. Seven preplant N, P, K, and S treatments, including none, all (each at 100 mg·L-1 of substrate), all minus one of each of the nutrients, and N at one additional rate of 50 mg·L-1, were tested. Postplant fertilization was applied to all treatments as 13 N-0.9P-10.8K at 50 mg·L-1 N beginning 1 week after sowing and was increased to 100 mg·L-1 N when the fourth true leaf appeared. The resultant seedlings were transplanted into 48-cell flats and grown into marketable stage for further evaluation. For maximum potential growth, N, P, K, and S were needed as preplant fertilizer. However, compact shoots, not maximum growth, are generally desired in commercial production. Thus, K and S can be omitted since their contribution to growth was only occasional and small. To further ensure a consistently desirable level of compactness, it was necessary to omit N or P or both in addition to K and S. Omission of N alone yielded the most desirable compact plant qualities, including suitable reduction in final seedling size. Omission of P alone yielded larger reductions in height and shoot dry weight of seedlings compared to N omission, and a delay of 2 to 4 days in flowering of bedding plants. Omission of the four nutrients, compared to -P, resulted in similar seedling growth reduction and bedding plant flower delay. Since N omission lowered the salt (electrical conductivity) level of substrate more than P omission and had no negative impact on subsequent bedding plant flowering compared to the other two treatments, N omission would be the more desirable of the three. However, N omission resulted in chlorotic seedlings, but these quickly turned green upon restoration of N. Omission of P or all four nutrients resulted in desirably deep green seedlings. Growth of gomphrena seedlings, a high-fertilizer requirement category of taxa, was suppressed when the preplant rate of N was 50 mg·L-1 compared to 100 mg·L-1, while growth of impatiens, a low-fertilizer requirement category of taxa, was essentially equivalent at these rates. Preplant additions of nutrients applied at 100 mg of nutrient element per liter of substrate lasted for the following numbers of days; NO3-N, 18-25 days; NH4-N, 12-20 days; K2O, 27 days; PO4-P, >35 days; and SO4-S, >35 days.
The effect of CO2 concentration (330 and 675 μL·L−1) and photosynthetic photon flux (PPF) (mean daily peaks of 550–1400 μmol·m−2·s−1) on total mineral contents in shoots was studied in chrysanthemum [Dendranthema ×grandiflorum (Ramat) Kitam ‘Fiesta’] during three times of the year. Growth (as measured by shoot dry weight) and shoot mineral contents (weight of nutrient per shoot) of hydroponically grown plants were analyzed after 5 weeks. There was a positive synergistic interaction of CO2 concentration and PPF on growth with the greatest growth at high PPF (1400 μmol·m−2·s−1) with high CO2 (675 μL·L−1). When growth was not used as a covariate in the statistical model, both CO2 concentration and PPF significantly affected the content of all eight nutrients. However, after growth was included as a covariate in the model, nutrients were classified into three categories based on whether CO2 concentration and PPF level were needed in addition to growth to predict shoot nutrient content. Neither CO2 concentration nor PPF level was needed for Mg, Fe, and Mn contents, whereas PPF level was needed for N, P, K, and Ca contents, and both CO2 concentration and PPF level were required for B content.