MINERAL CONTENT OF MELON FRUIT (CUCUMIS MELO L.)
Melons are highly demanding, thermophilous plants, which is why they are unpopular among fruit growers. Melon cultivation requires special treatment methods for the improvement of microclimatic conditions. Seven Polish melon cultivars are presently grown on the domestic market. They are well adapted to the local climate. The growth rate, vigor, fruit shape, fruit size, rind color and flesh thickness of those cultivars vary. The objective of this study was to determine the mineral content of edible parts of four field-grown melon cultivars in the Warmia region (NE Poland). This study discusses the mineral content of melon fruit subject to the investigated cultivar and cultivation method. In Poland, melon production is difficult and unreliable. The main problem is the selection of an appropriate cultivar and cultivation method. The analyzed material consisted of four Polish melon cultivars: Malaga F1, Melba, Oliwin, Seledyn F1, grown in a field experiment without protective cover, under polyethylene (PE) sheet cover, under non-woven polypropylene (PP) cover, with soil mulching, as well as with soil mulching under PE sheet cover or nonwoven PP cover. The highest concentrations of total N, K, Ca and Cu were determined in melon fruit of cv. Oliwin. Significant variations in total nitrogen and phosphorus levels in the edible parts of melon plants were noted subject to the applied cultivation method. Cucumis melo L. grown in the control treatment without protective cover was marked by significantly higher levels of total nitrogen and phosphorus in the fruit, compared with fruit grown with the use of other cultivation methods. The results of this study indicate that the fruit of melon plants cv. Seledyn grown in mulched soil under non-woven PP cover was characterized by the most favorable Ca:Mg and Ca:P ratios in comparison with fruit from the remaining treatments.
The effect of transplanting date and covering on the growth and development of melon (Cucumis melo L.)
The effect of different transplanting dates (May 15, May 25, and June 4) and date of polypropylene fiber removal (4 and 8 weeks after transplanting, and control without covering) on the growth, development, and yield of melon ( Cucumis melo L.) were investigated. The experiment was carried out during 2008–2010 in eastern Poland (51°53'23.64" N, 22°27'47.96" E). Plants planted on May 15 were longer by 22% and 56%, weighed more by 39% and 76%, and their leaf area index (LAI) was higher by 24% and 117% compared to plants planted on May 24 and June 4, respectively. However, delayed planting reduced the period of growth and development by 7 and 17 days, respectively. When the covering application period was extended from 4 to 8 weeks, stem length increased by an average of 23% and LAI by 38%, but harvest was delayed by 6 days. The respective yields of melon fruits planted on May 15, May 25, and June 4 amounted to 5.09, 4.73, and 3.99 kg m −2 . The covering of plants planted at each date contributed to an increase in yield and in the share of marketable fruit yield in the total yield. However, the length of the cover application period did not affect yield levels.
Unidirectional hexagonal rare-earth disilicide nanowires on vicinal Si(100)-2×1
Rare-earth disilicide nanowires grown on vicinal Si(100) with a miscut of 2–2.5° toward the [110] azimuth at 600 °C were studied by scanning tunneling microscopy and compared with those grown on flat Si(001). In contrast to rare-earth disilicide nanowires grown on flat Si(100) surfaces, the nanowires grow unidirectionally along the [01̄1] direction of the vicinal Si(100) surface. Rare-earth disilicide nanowires form bundles composed of single nanowire units on both flat and vicinal surfaces. Yet, on the vicinal surface, the bundle width is comparable to the width of the terrace. The average nanowire length on the vicinal substrate is longer than that on the flat substrate. Scanning tunneling spectroscopy shows that the rare-earth disilicide nanowires have metallic properties.