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181.
F. Haworth T. J. Cleaver J. M. Bray 《The Journal of Horticultural Science and Biotechnology》2013,88(3):243-255
Red beet was grown in factorial manurial experiments at two sites: at Wellesbourne annually from 1954 to 1964 in a rotation of vegetable crops and at Efford in 1959 only.At Wellesbourne applications of FYM (20 tons per acre per crop), together with NPK fertilizers, consistently gave much higher yields than mineral fertilizers alone, but the relative effect of FYM did not increase as the experiment proceeded.In the presence of FYM, yields of red beet increased with increasing rates of application of Nitrochalk (up to 124 lb. N per acre), but applications of phosphate and potash fertilizers did not affect yields.In the absence of FYM, phosphate fertilizers did not increase yields significantly after 1959; there was an important interaction between the effects of the applications of Nitrochalk and SUlphate of potash. Each fertilizer applied alone produced small increases in yield, but when they were applied together at the highest rates used (186 lb. Nand 192 lb. K2O per acre) large increases in yield were obtained and there was some indication that an even higher rate of application would have given a further increase in yield. At Efford, nitrogenous fertilizers increased yields significantly.Applications of FYM increased the potassium and decreased the calcium and magnesium contents of red beet leaves and had only small effects on the nitrogen and phosphorus contents; in the roots, only the potassium content was altered (increased) by the FYM applications.In general, in the absenc~ of FYM only potash fertilizer applications had large, consistent and significant effects on the mineral composition of the leaves and roots. At both sites, applications of sulphate of potash increased the potassium content of the leaves and had a much smaller depressing effect on the calcium and magnesium contents of the leaves but not, in general, of the roots.The effects of the nitrogenous fertilizers on the total nitrogen content of the roots were relatively small, but could be important in relation to the processing quality of the beet.The marked differences between the responses of red beet and early potatoes to the manurial treatments are discussed in relation to the nutrient contents of the plants. 相似文献
182.
The goal of cancer surgery is to achieve a “clean” microscopic resection, with no residual tumour remaining in the wound. To achieve that goal, the surgeon typically incorporates a measured buffer of grossly normal tissue about the entire circumference of the tumour. Microscopic analysis of the resection boundaries is then performed to determine if all traces of the tumour have been completely removed. This analysis is thought to provide a surrogate indication as to the likelihood for that tumour to recur after surgery. However, it is recognised that tumour recurrence may not occur even when microscopic evidence of tumour has been identified at the resection margins, and recurrence can also occur when conventional histology has considered the tumour to have been completely removed. The explanations for this dichotomy are numerous and include technical and practical limitations of the processing methodology, and also several surgeon-related and tumour-related reasons. Ultimately, the inability to confidently determine when a tumour has been removed sufficiently to prevent recurrence can impact on the ability to provide owners with confident treatment advice. In this article, the authors describe the challenges with defining the true extent of the tumour margin from the perspective of the surgeon, the pathologist and the tumour. The authors also provide an analysis of why our current efforts to ensure that all traces of the local tumour have been successfully removed may provide an imperfect assessment of the risk of recurrence. 相似文献