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M.S. Stanghellini, J.R. Schultheis, and J.T. Ambrose

Very little is known about the rate at which pollen grains are mobilized within insect-pollinated crop systems, and this is especially true the for commercial production of field-grown cucumber (Cucumis sativus L.), monoecious muskmelon (Cucumis melo L.), and triploid watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. The rates of pollen depletion for these crops were therefore investigated on plots simulating commercial crop production using a mixed honey bee (Apis mellifera L.) and bumble bee (Bombus impatiens Cresson) pollinator complex. At anthesis, staminate cucumber, muskmelon, and watermelon flowers contained on average 10539, 11176, and 30739 pollen grains/flower, respectively. At the time flowers closed in the early afternoon (1300 to 1400 hr), only 61% of the total pollen produced had been removed from staminate cucumber flowers, 44% to 62% from muskmelon, and 81% from watermelon flowers. The results suggest that total pollen production in these crops may not necessarily reflect total pollen availability to floral visitors (bees). However, of the total amount of pollen actually removed per flower, >57% occurred during the 2 h following flower anthesis of cucumber and muskmelon, and >77% occurred during the 2 h following flower anthesis of watermelon. Thus, most of the accessible pollen was removed shortly after anthesis, which is when these crops are most receptive to pollination. Nonviable triploid and viable diploid watermelon pollen were removed at similar rates (P = 0.4604). While correlation analyses were not possible for the influence of variable bee abundance on pollen depletion rates, higher bee populations in one year appeared to increase the rate at which pollen grains were removed from staminate flowers.

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Sven Verlinden, Silvanda M. Silva, Robert C. Herner, and Randolph M. Beaudry

same time, track changes in soluble carbohydrate for that section. The difference in the rate of carbon flux through CO 2 emission and sugar depletion was calculated for each section and the data were again described using a single empirical equations

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Heather L. Papinchak, E. Jay Holcomb, Teodora Orendovici Best, and Dennis R. Decoteau

foliage plants in controlled chambers (that simulated indoor environments) for their ability to reduce concentrations of several air pollutants. Depletion rates of known concentrations of air pollutants within the enclosed chambers containing plants were

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Neil Mattson and Heiner Lieth

conducted as described previously. Determination of depletion curves. On the morning of day 20 after the start of each deprivation treatment, a nutrient depletion experiment was conducted to measure nutrient absorption rates as a plant draws down the

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Xiuju Bian, Emily Merewitz, and Bingru Huang

water depletion and ET rate. SWC was maintained at 25% under well-watered conditions throughout the entire study period (28 d) ( Fig. 1 ). The SWC declined to the lowest level of ≈5% by 21 d of drought and at this level at 28 d for TE-treated and

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Jeffery C. Kallestad, John G. Mexal, Theodore W. Sammis, and Richard Heerema

to a week from the time water is ordered. Therefore, growers must be able to predict several days in advance when their soil moisture will be at a management allowable depletion (MAD) level. New Mexico is one of the top three producers of improved

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Sea Yeat Choon and Phebe Ding

of inflorescence (g) − dry weight of inflorescence (g)]/fresh weight of inflorescence (g)} × 100%. Respiration and ethylene production rates. The concentrations of carbon dioxide (CO 2 ) and ethylene (C 2 H 4 ) produced by the inflorescences were

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Ran Chen, Weitao Jiang, Haiyan Wang, Fengbing Pan, Hai Fan, Xuesen Chen, Xiang Shen, Chengmiao Yin, and Zhiquan Mao

ozone-depleting effects ( Hoffmann et al., 2020 ). Since then, several chemical fumigants have appeared on the market to replace methyl bromide, such as benzamide, sodium methylamine, and 1,3-dichloropropene ( Yan et al., 2017 ). Metham sodium, a type of

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Diana Niñirola, Juan A. Fernández, Encarnación Conesa, Juan A. Martínez, and Catalina Egea-Gilabert

-filled channels that facilitate the internal diffusion of gases ( Evans, 2003 ). Another developmental adaptation to depleted oxygen is the presence of adventitious roots, which often contain extensive aerenchymatous tissue and are thus less affected by hypoxia

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Michael J. Costello

channels and accelerates the rate of organic matter decomposition, which collectively can lead to poor water penetration ( Gulick et al., 1994 ). Maintaining and managing floor vegetation through mowing is much less disruptive to the soil and therefore can