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Isolated leaf cuticles and intact plants of one‐year‐old potted ‘Red Haven’ trees grown in the greenhouse were used to study the permeability of leaf cuticles to boron (B). The isolated leaf cuticles were prepared enzymatically. Flux was determined using a transport cell. Permeability coefficient (P) was calculated and used as the parameter of cuticle permeability to B. For intact plant studies, enriched‐10B boric acid solution was evenly spread onto the abaxial or the adaxial side of a leaf. The trees were sacrificed three days after the treatment and selected plant parts were analyzed with ICP‐AES and ICP‐MS spectrometers. The 10B content was used as the parameter of B permeability in vivo. The permeability coefficient of peach leaf adaxial cuticle was in the order of 10‐7 cm/sec. There were no difference in the permeability coefficients among B concentration and surtactant treatments. The pH had variable effect on B absorption through the cuticle of the adaxial side of the leaf. For the in viv...

One‐year‐old potted ‘Red Haven’ peach (Prunus persica L. Batsch) trees grown in the greenhouse were used to study the mobility of boron (B). Enriched‐10B‐boric acid solution was evenly spread onto the abaxial side of a leaf. After harvesting at different time intervals, selected plant parts were analyzed by ICP‐AES and ICP‐MS spectrometry. The 10B content was used as the parameter of B mobility. The results showed that among the six B concentrations (0, 150, 300, 600, 900, and 1,200 ppm) studied, the 1,200 ppm treatment had the highest 10B content in every plant tissue. There was little difference between the middle and bottom treatments in the leaf position‐treated experiment. However, if leaf area was not considered, the terminal leaf was less efficient in taking up 10B than the other two positions in the same experiment. Plastic coverage on the treated leaf helped the uptake of the treated 10B‐boric acid. High relative humidity (100% RH) treated plants had higher 10B content than the low RH‐tr...

This study addresses the need to determine accurately mineral element concentrations in roots grown in soil so that valid measurements of element uptake and translocation can be made. Wheat (Triticum aestivum L., cv ‘Nugains') was planted in seven soils. Two seeds were planted in each soil and two seeds were planted in a Versapor bag that had been buried in the soil in the same 1.3‐L ceramic pot. The bag separated the roots from soil. The plants were harvested four weeks after planting. Tops and roots were analyzed separately for 12 elements. Estimates were made for the contribution of each element from soil particles contained in the sampled portion, by using the titanium (Ti) concentration in root sample as a measure of contamination by soil. Concentration corrections ranged from an increase of 14% for Na to a decrease of 131% for Al. Corrected estimates of Al and Fe concentrations in the sample portion were usually unreasonably high or low. In most cases, corrected concentration estimates appe...

Wheat, barley and oat plants, grown in the absence of added Ni (‐Ni), accumulated 15 to 20 fold higher levels of urea in their leaf tips than Ni supplied plants (+Ni). Oat plants (‐Ni) matured 15 days earlier than +Ni‐oat plants. When grown from low Ni seed, Ni‐deprived barley plants had significantly (30%) lower root and shoot weights than +Ni‐plants and displayed characteristic symptoms that could be eliminated by Ni supplementation. Tissue Fe‐levels were positively correlated with tissue Ni‐levels.

The two longer papers on “The Aims of Week‐Day Religious Education,” as well as the shorter statements which follow, have been prepared at the request of The Committee on Program and constitute an advance discussion of the first topic of the Conference, on March 31st and April 1st. The discussion at that meeting will proceed on the assumption that all have studied these papers.

(1942). Predicting College Success. The Journal of Higher Education: Vol. 13, No. 5, pp. 263-267.

Within the past few years numerous studies have been made regarding student-teacher relationships. However, a majority of these studies such as the one by Wickman (6) has been con cerned primarily with the attitude of the teacher toward the stu dent's behavior and actions rather than with the attitude of the student toward the various factors of the classroom and the ped agogical procedures of the teacher. Although there has been a number of studies (e. g., 1,2,3, 4, 5) that are oriented with res pect to the attitudes of students toward their teachers, there ap pears to be a need for a comprehensive investigation at the sec ondary school .level. It is the contention of the writers that rel atively greater attention should be given to the students' point of view regarding the factors that make secondary school exper ience both enjoyable and beneficial than has been customary in thefepast.