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  • Author or Editor: Megan M. Kennelly x
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Moss is common on creeping bentgrass (Agrostis stolonifera L.) putting greens, and more control options are needed. Spot treatment of sodium bicarbonate (44.2 g·L−1) was compared with broadcast sprays of carfentrazone-ethyl (50.5 or 101 g a.i./ha), chlorothalonil (8.2 or 12.8 kg a.i./ha) and a tank mixture of chlorothalonil, mancozeb, and thiram (8.2, 9.8, and 11.5 kg a.i./ha) in 2006 in Lemont, IL. Sodium bicarbonate suppressed moss growth equally as the conventional products. These results led to further experiments in 2008 in which moss suppression was evaluated within standard and alternative putting green management regimes in Manhattan, KS, and Lemont, IL. The standard approach included spring and fall applications of carfentrazone-ethyl (101 g a.i./ha) for moss control, biweekly applications of urea (46N–0P–0K) at 15 kg N/ha, and applications of chlorothalonil (8.2 kg a.i./ha) on a 14-day interval. Conversely, the alternative approach included spring and fall spot treatments of sodium bicarbonate (44.2 g·L−1) for moss control, biweekly applications of a natural organic fertilizer (8N–1P–3K) to provide nitrogen at 15 kg N/ha, and applications of chlorothalonil (8.2 kg a.i./ha) only when dollar spot reached a predetermined threshold level. Standard and alternative regimes were compared at both 3.2- and 4.0-mm mowing heights; synthetic and organic fertilizers applied alone without pest control approaches were included as controls. In Kansas and Illinois, moss coverage using the alternative management regime was not significantly different from that on greens managed using the standard regime. In Kansas, moss severity at a 3.2 mm was 1.6-fold higher than at the 4.0-mm height. In Illinois, sodium bicarbonate suppressed moss equivalently to the carfentrazone-ethyl treatment, and in the fertilizer-only controls, mowing at 3.2 versus 4.0 mm led to more moss coverage. These studies demonstrate that moss can be effectively suppressed on greens using spot applications of sodium bicarbonate and reduced moss encroachment is possible with higher mowing heights.

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Two greenhouse studies were conducted to examine effects of nitrogen source on primary and secondary metabolism of pac choi (Brassica rapa L. subsp. chinensis cv. Mei Qing Choi) and diamondback moth (Plutella xylostella L.) consumption, development, survival, and body weight. Applications of a liquid organic source of nitrogen (fish hydrolysate fertilizer) were compared with a conventional fertilizer to determine whether nitrogen source directly impacts pac choi chemistry (elemental composition and phenolics) and biomass and indirectly affects diamondback moth fitness parameters. There was no significant effect of fertility treatment on pac choi chemistry or biomass with the exception of percent leaf phosphorus, which was significantly higher in the conventional fertility treatment, and p-coumarin, which was significantly higher in the organic fertility treatment. Diamondback moth also affected plant chemistry. Both calcium (Ca) and magnesium (Mg) were significantly higher in plants infested with larvae compared with uninfested plants. Fertilizer affected diamondback moth fitness with percent survival and cohort development significantly reduced on pac choi associated with the organic fertilizer. However, pac choi receiving the organic treatment was similar in regard to primary nutrients and secondary compounds compared with plants that received a conventional fertilizer.

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