Using saturation extract procedures, fifteen extractants were evaluated for their ability to remove B, Fe, Mn, and Zn from a peat and vermiculite (50:50% by volume) medium amended with three levels of micronutrients. A modified saturated media extract test procedure was developed in which 30 ml of .005M DTPA was added per 100 cc of sample to be extracted. The use of this method enhanced resolution of micronutrient cation test levels in 3 media while producing only minor changes in macronutrient, pH, or soluble salt test results when compared to DI water extractions.

Chemical growth retardants (2-chloroethyl)trimethylammonium chloride (chlormequat), succinic acid-2,2-dimethylhydrazide (SADH, daminozide) and α-cyclopropyl-α-(ρ-methoxyphenyl)-5-pyrimidinemethanol (ancymidol) were tested on Reiger Elatior begonia ‘Schwabenland Red’ (Begonia × hiemalis Fotsch). Chlormequat applied as a spray of 0.30% active ingredient (a.i.) (1:40 dilution of commercial product) caused height retardation in high and low light periods, being most effective in the winter. A 0.30% drench was excessive under low light conditions whereas both 0.30 and 0.60% drenches were ineffective under high light conditions. No significant height retardation was found when SADH was applied as a spray at concentration up to 0.50% a.i. Ancymidol was effective as a drench at 0.125 mg per 15 cm pot under both high and low light conditions. Ancymidol sprays at concentrations up to 33 ppm were ineffective.

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.

The ionic Ca content of expressed apple juice conceivably could be used to estimate the total calcium content of fruit flesh. To evaluate this method, samples of 2 strains of ‘Delicious’ apple (Malus domestica Borkh.) were analyzed at 2- to 3-week intervals, from 4 weeks after full-bloom until full-maturity. Ionic Ca in the juice (juice Ca) was analyzed with a selective electrode, total Ca in the flesh (flesh Ca) with a plasma emission spectrophotometer. The correlation coefficient between calcium concentration in flesh vs. juice was very low during the early stages of fruit development, but increased to +0.758 (significant at P<0.0l) for samples collected 5, 3, and 0 weeks prior to fruit maturity. The correlation was generally significant at P<0.01 when all sampling dates were used (r = 0.734 for ‘Miller Spur’, +0.928 for ‘Starking’, and +0.831 for both strains). The calcium concentration in juice samples taken within 35 days of physiological fruit maturity paralleled the calcium concentration in the flesh on any given date, but was not a reliable predictor of flesh Ca concentration in fruit harvested 2 to 3 weeks thereafter.

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.