Flemish greenhouse growers predominantly use handheld spray guns and lances for their crop protection purposes despite the heavy workload and high risk for operator exposure associated with these techniques. These spray application techniques have also shown to be less effective than spray boom equipment under many conditions. Handheld spraying techniques are less expensive, however, and they are more flexible in practical use. Many growers also erroneously believe that high spray volumes and pressures are needed to assure good plant protection. The aim of this work was to evaluate the spray deposition, penetration, and uniformity between a manually pulled horizontal spray boom as compared with a spray gun under controlled laboratory conditions. In this study, we evaluated six spray application techniques, i.e., three spray boom and three spray gun techniques. In general, the deposition results were comparable between the spray boom and the spray gun applications. The spray boom applications, however, resulted in a more uniform spray distribution. At the plant level, the spray distribution was not uniform for any of the techniques used; the highest deposits were observed on the upper (or adaxial) side of the top leaves. Using spray guns at a higher spray pressure did not improve spray penetration in the canopy or deposition on the bottom (or abaxial) side of the leaves. Of the different nozzle types tested on the spray boom, the extended range flat fan XR 8003 gave the best results. Crop density clearly affected crop penetration and deposition on the bottom side of the leaves.
Dieter Foqué, Jan G. Pieters, and David Nuyttens
Danielle E. Hammond, Amy L. McFarland, Jayne M. Zajicek, and Tina M. Waliczek
The objective of this study was to investigate the relationship between parental attitudes toward nature and their child's outdoor recreation and how these attitudes related to their reports of their child's health problems. The sample for this study consisted of parents of 6- to 13-year-old children from the United States, who accessed the survey from an informational website for gardeners between Mar. and Aug. 2009. Surveys were collected until 142 completed questionnaires were received. The online survey included questions about parents' attitude toward nature, parents' attitudes toward their child's outdoor recreation, an inventory of potential children's health problems, the time children spent in various indoor and outdoor activities, and demographic questions. Descriptive statistics were used to tabulate mean scores on the parental attitude toward nature (PAN) scale and parental attitude toward their child's outdoor recreation (PACOR) scale, both of which indicated overall positive views. Pearson's product–moment correlations indicated statistically significant relationships between the PAN scale, the PACOR scale, and time children spent outdoors. Relationships between time spent indoors on video games or watching television and health problems in children were identified. Time spent outdoors in free play was inversely related to reports of health problems in children.
Holger Weichert, Stefanie Peschel, Moritz Knoche, and Dieter Neumann
Recent studies established that some ferric salts, including FeCl3, decrease water permeability of the sweet cherry (Prunus avium L.) fruit exocarp and fruit cracking, presumably by a pH-dependent precipitation reaction that blocks high-flux pathways across the fruit surface. The objectives of our study were the following: to establish the effect of receiver pH on penetration of 55FeCl3 through excised exocarp segments (ES) and isolated cuticular membranes (CM) and to localize any Fe precipitates in the epidermal system of mature sweet cherry fruit. Penetration was studied using an infinite dose diffusion system where 55Fe penetrated from donor solutions of ferric salts (10 mm, pH 2.2–2.6) or EDTA-Na-Fe(III) (10 mm, pH 5.0) across an interfacing ES or CM into aqueous receiver solutions of pH values ranging from 2.0 to 6.0. For receiver pH 2.0, 55Fe penetration of the ES from a 10 mm FeCl3 donor (pH 2.6) was linear with time, but for receiver pH ≥ 3.0, penetration was low and insignificant. Increasing the pH of the water receiver from 2.0 to 6.0 in the course of an experiment resulted in an immediate halt of penetration regardless of whether 55Fe penetration occurred from FeCl3 (pH 2.6), Fe(NO3)3 (pH 2.6), or Fe2(SO4)3 (pH 2.4) as donor solutions (all at 10 mm). Only from EDTA-Na-Fe(III) (pH 5.0) 55Fe penetration continued to occur albeit at a decreased rate (−30%). At receiver pH 2.0, the 55FeCl3 flux through stomatous ‘Sam’ ES averaged 10.4 ± 2.3 pmol·m−2·s−1 and was positively correlated to stomatal density. Conventional and analytical electron microscopy (energy dispersive X-ray analysis, electron spectroscopic imaging, and electron energy loss spectroscopy) identified ferric precipitates in periclinal and anticlinal cell walls of epidermal cells underlying the cuticle, but not within the cuticle. These data indicate that the lack of 55Fe penetration from donor solutions of ferric salts through the ES into a receiver solution at pH ≥ 3 and the previously reported decrease in water uptake and cracking as a response to immersing fruit in solutions of ferric salts are the result of a precipitation reaction at the cuticle/cell wall interface in the sweet cherry exocarp. Although spray application of ferric salts is prohibitive for ecotoxicological reasons, understanding their mechanism in decreasing water uptake and fruit cracking may be helpful in the search for alternate compounds that are effective and ecotoxicologically acceptable.
Pascal Braekman, Dieter Foqué, Marie-Christine Van Labeke, Jan G. Pieters, and David Nuyttens
As a result of the decreasing availability of authorized plant protection products, adequate pest control becomes more difficult in many ornamental crops and almost no information is available about the optimization of spray application techniques in ornamental crops. Yet, spray boom systems—instead of the still predominantly used spray guns—might improve crop protection management in greenhouses considerably. Application rate, nozzle type, and configuration will influence the spray deposition and, as such, its efficiency. In this study, spray deposition in ivy pot plants [Hedera algeriensis cv. Montgomery, Hibb.], grown on hanging shelves in greenhouses, was compared with a traditional spray gun with a disc-core nozzle and a manually pulled trolley equipped with two vertical spray booms. The sprayings with the spray gun were performed at an application rate of 8500 L·ha−1. For the vertical spray boom system, two different reduced application rates (2500 and 5000 L·ha−1) with five different combinations of nozzle type, size, and pressure for each application rate were investigated. This research underlined that, besides the application rate, also the spray application equipment used has an important effect on the spray depositions. Nozzle type, size, and pressure on the vertical spray boom system only had a minor effect on the spray deposition. Although the spray gun performed well on the easily accessible crop zone with the runners, its performance in the more dense main crop zone was inferior. With 240% more sprayed liquid (8500 L·ha−1) and chemicals, the realized depositions in this crop zone were not significantly different from the ones obtained with the vertical spray boom system applying only 2500 L·ha−1. Spraying at 5000 L·ha−1, the vertical spray boom system achieved a 82.9% higher overall spray deposition in the main crop canopy zone compared with the spray gun at an application rate of 8500 L·ha−1. For the sprays applied with the vertical spray boom system, doubling the application rate resulted in equally higher spray depositions, except for the inner canopy deposition for which higher application rates were more effective.
Holger Weichert, Carina von Jagemann, Stefanie Peschel, Moritz Knoche, Dieter Neumann, and Wilfried Erfurth
Water uptake through the exocarp of intact sweet cherry [Prunus avium (L.)] fruit was determined gravimetrically in an immersion assay (25 °C). Fruit with sealed pedicel/fruit juncture were incubated in water during the first interval (0 to 0.75 hour) and in 10 mm salt solutions of selected cations during the second (0.75 to 1.5 hours) and third interval (1.5 to 2.25 hours) of an experiment. Rates of water uptake (F) were calculated for first, second and third intervals (FI, FII and FIII, respectively) and salt effects indexed by the ratios FII/FI and FIII/FI. AgNO3 (FII/FI = 0.65), NaCl (0.70), BaCl2 (0.67), CdCl2 (0.69), CuCl2 (0.42), HgCl2 (0.58), and SrCl2 (0.69), and the salts of trivalent cations AlCl3 (0.50), EuCl3 (0.58), and FeCl3 (0.49), significantly decreased water uptake into mature `Sam' fruit as compared to the water control (0.87). KCl (0.82), NH4Cl (0.85), CaCl2 (0.75), MgCl2 (0.88), MnCl2 (0.81), and ZnCl2 (0.72) had no effect, LiCl (1.00) increased uptake. Similar data were obtained for FIII/FI. The effect of FeCl3 on water uptake was independent of the presence of CaCl2, AlCl3, or CuCl2, as sequential or simultaneous treatment with these salts reduced water uptake to the same extent as with FeCl3 alone. Increasing FeCl3 concentration up to 1 mm decreased uptake, higher concentrations had no further effect. FeCl3 and CaCl2 to a smaller extent decreased water uptake in developing `Regina' sweet cherry fruit (55 to 91 days after full bloom). FeCl3 had no significant effect on water uptake along the pedicel/fruit juncture, but markedly reduced uptake through the exocarp of all cultivars investigated (`Burlat', `Early Rivers', `Hedelfinger', `Knauffs', `Regina', `Sam', `Summit', and `Van'). Effects of CaCl2 on water uptake were limited to `Burlat', `Early Rivers', and `Hedelfinger'. CaCl2 and FeCl3 both decreased fruit cracking, but FeCl3 was more effective. The mode of action of mineral salts in decreasing water uptake and fruit cracking and their potential for field use are discussed.
Bhimanagouda S. Patil, G.K. Jayaprakasha, and Amit Vikram
, sweetpotato/yam, sugarcane, and soybean) contribute ≈75% of human food ( Prohens et al., 2003 ). It is now well established that diets rich in fruits and vegetables (FAV) may have protective effects against cardiovascular disease and certain forms of cancer
Dean A. Kopsell, Carl E. Sams, T. Casey Barickman, Dennis E. Deyton, and David E. Kopsell
fertilization strategies to help fortify both animal and human diets ( Finley, 2007 ; Hawkesford and Zhao, 2007 ; Reilly, 1998 ). Because the soil is the primary source of Se, levels of Se in plant foods and in the animals that consume them show considerable
Harbans L. Bhardwaj and Anwar A. Hamama
nutritionally healthful. The contents of Fe and Zn, two elements with worldwide deficiency in human diets, were unaffected by cultivars. Two cultivars developed at Kansas State University (‘KS 8200’ and ‘KS 8227’) had significantly higher S content (725 and 687
Roland Ebel, Esmaeil Fallahi, John L. Griffis Jr., Dilip Nandwani, Donielle Nolan, Ross H. Penhallegon, and Mary Rogers
declines while they concurrently change their nutrition habits, often culminating in a “western diet” (high intake of fats, added sugars, animal-source foods, and refined carbohydrates). A global trend toward obesity and diabetes is the result ( Popkin
M. Courtney, M. Mcharo, D. La Bonte, and W. Gruneberg
micronutrients iron, zinc, and vitamin A are essential to the human diet, large segments of the global population experience health consequences from inadequate intake ( Cichy et al., 2005 ; Long et al., 2004 ; Mason et al., 2001 ). Strategies to overcome these