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- Author or Editor: R. M. Davis Jr. x
The term “vein tract” is better than “suture” to denote the longitudinal indentations or unnetted strips which sometimes characterize the outward appearance of fruits of Cucumis melo L., reticulatus Naud. The term “suture” has a botanical ring in comparison to “grooves” or “stripes,” and I confess to having used it as much as anybody. Unfortunately, “suture” is here applied incorrectly; thus it is misleading to one who may be considering physiological explanations for unexplained variations in this surface feature.
Concentrations of soluble solids (SSC) in fruits of Cucumis melo L., cv. PMR 45, were positively correlated with 2 physical measures of soil samples from producing fields: a) the degree of cracking which occurred during dehydration, and b) the rapidity with which water or a CaSC>4 solution percolated the soils. Very low SSC was associated with sandy, non-cracking soils, which in addition permitted only low rates of percolation. Low SSC also was found to be associated with soils having subsurface hardpans or dense subsoil strata, and also with the distance to lower bounds of plant containers and experimentally placed barriers which obstructed downward root growth. SSC, under adverse conditions, varied further as a function of fruit numbers per plant.
Retention and early growth of ovaries of tomato cultivar Earlipak No. 7 (L. esculentum, Mill.) and a related breeding line were recorded for several weeks at 4 locations. Percent fruit-set, defined as the percentage of flowers of which ovaries were retained and reached a diameter of at least ¼ inch in 2 weeks, was not a reliable index of either ovary retention or early ovary growth. Important information concerning the fruiting of tomato may be lost, when data are collected on the basis of the defined fruit set rather than observed ovary retention and ovary growth specifically.
A study was conducted to observe changes in mineral element concentrations within different sections of leafy stem cuttings of Hibiscus acetosella ‘Panama Red’ (PP20121) during a 21-day propagation period under standard industry propagation conditions. Concentrations of 13 mineral elements were analyzed in leaves, lower stems (below substrate), upper stems (above substrate), and roots at 3-day intervals. Before root emergence (day 0–6), P, K, Zn, Ca, and Mg concentrations decreased in the shoots (including upper stems and leaves), whereas Zn, Ca, and B concentrations decreased in the lower stems. Sulfur increase occurred in lower stems before root emergence. After rooting (day 9–21), N, P, Zn, Fe, Cu, and Ni concentrations decreased in the roots; K, S, B, and Mg concentrations increased. In the lower stems, N, P, K, S, and Zn concentrations decreased, whereas B increased. Potassium concentration decreased in the leaves; P, K, S, and Zn decreased in the upper stems. Calcium and Mg increased in leaves. This study indicates specific nutrients are important in adventitious rooting, and that it is important to analyze rooting as a function of fine-scale temporal measurements and fine-scale sectional measurements.
A table is presented from which the percentage distribution of a crop into various maturity classes can be estimated for an optimizing or non-optimizing harvest day. Two or three characteristics of the crop must be known or guessed for predictive or speculative purposes. The use of the table throws light on the type of information which must be at hand in order to work intelligently toward a once-over harvest in those perishable crops which at present are not well adapted for it.
For the tomato cultivar ‘Earlipak No. 7’, measurements were made on several components which contribute to variations in harvest patterns. Components which were observed at 4 locations were: per cent of ovaries retained; the per cent of these which grew and matured; the sizes of ovaries at selected periods of time; the variance in this component; the elapsed time between flower and maturity, and between interim stages; the variances in these components. Sizes and seed numbers of matured fruits were observed. Correlation coefficients among the variates are presented. It appears that measurements upon each of the components and at least one more (flower production rates) are essential to a fundamental understanding of variations in the harvest pattern on a genetic or environmental basis. The apparent influence of seed number on growth rates and mature weight is brought into question.