Most managed turfgrass species require frequent inputs to maintain an acceptable level of quality. Among these inputs, nitrogen (N) fertilization is usually the most limiting in terms of growth and development. However, N fertilization is also linked to non-point source (NPS) pollution. White clover (WC) is known for its ability to provide N when mixed into stands of turfgrass, and does not pose a threat for NPS pollution. Two field studies were designed to investigate the effects of WC inclusion in stands of cool-season turfgrasses. In the first field study, three cultivation techniques were examined for establishment of WC into preexisting turfgrass stands at three different seasonal timings. Scalping during the summer was seen as providing the highest WC populations, although scalping treatments also caused the most initial damage to the turfgrass. In the second field study, mixed stands of turfgrass and WC were examined for response to several weeks of traffic simulations, with WC withstanding the traffic events. Additionally, a greenhouse study was implemented to examine the effects of several commercial broadleaf herbicides on two WC varieties. Only 2,4-D was shown to be safe for application to both WC varieties, although Microclover did show tolerance to quinclorac applications.

Aquaponics, the integrated production of fish and hydroponic crops in a recirculating system, is an intensive cultivation method in which metabolic fish wastes fertilize plants. This study compares the effects of two aquafeeds on Red amaranth (Amaranthus tricolor) productivity and on water quality under cultivation of Blue tilapia (Oreochromis aureus), with three aquaponic units (n=3) per treatment over a 60-day trial. The fishmeal-based control feed contains higher crude protein (40%) and phosphorus (1.12%) than the plant-based alternative feed (32% and 0.40%). The alternative feed resulted in a significantly higher amaranth crop yield (p

As water demand increases it will become more imperative for golf course superintendents, landscape managers, and other industry professionals to improve water use efficiency in the management of recreational turfgrass. Scheduling irrigation according to actual turfgrass evapotranspiration rates (ETT) is an integral component of efficient irrigation practices. Impracticality of field derived ETT for industry use, however, directs the need of weather station derived reference (predicted) evapotranspiration (ET0). To accurately predict (estimate) ETT of turf and other crops, scientifically derived landscape (crop) coefficients (Kc values) are used in conjunction with mathematical models that incorporate local meteorological data. Research is limited, however, in identifying Kc values and subsequent ET0 for turfgrass species selected and maintained under high intensity recreational practices congruent of golf courses and sports fields in the cool-humid northeast climate. Therefore, objectives of this study were to (i) observe and record ETT of three commonly selected recreational turfgrass species; 'Exacta' Perennial ryegrass (Lollium perenne L.), 'Touchdown' Kentucky bluegrass (Poa pratensis L.), and 'Memorial' Creeping bentgrass (Agrostis stolinifera L.) maintained as golf and sports turf, (ii) analyze the impact various management practices (nitrogen fertility and height of cut) have on ETT, (iii) develop accurate Kc values appropriate for use with the recommended FAO 56 Penman-Monteith mathematical model for accurate ET0 of recreational turf maintained in the cool-humid northeast. Four heights of cut (HOC) and two nitrogen fertility rates (N) were evaluated to determine their impact on turfgrass growth and subsequent water use and ETT of three recreational turfgrass species. Golf turf (creeping bentgrass) maintained at a lower height of cut than sports turf exhibited a smaller leaf area component and a significantly lower (20%) ETT. N applied as slow release (82%) throughout the growing season increased ETT by 5%, particularly with perennial ryegrass sports turf. Taller HOC also increased ETT by 10% due to increased leaf area indices and subsequent decreased resistance to ET. Predicted ET0 according to FAO 56 for all three years of the study (79 observations) captured 71% of ETT. Yearly and monthly calculations suggest less variable (cloudy) weather yielded more accurate ET0. Crop coefficient (Kc) values established in conjunction with FAO 56 ET0 ranged from 0.90 to 1.00 for shorter golf course turf (creeping bentgrass), and 1.15 to 1.25 for taller sports turf (Kentucky bluegrass and perennial ryegrass). Results indicate shorter grass exhibits a lower ETT than taller grass due to various factors, and in the case of industry application, FAO 56 ET0 can accurately estimate ETT of recreational turf in the cool-humid northeast when fitted with appropriate Kc values.

Abstract Plant Growth Regulator Sprays and Girdling: Potential Horticultural Techniques to Increase Fruit Retention and Yield of Longan (Dimocarpus longan Lour.) Trees in California Leila Graves June 2009 The longan is a subtropical fruit tree whose popularity is growing quickly among American consumers, and thus, could become a lucrative niche market for California growers. Trees planted as part of an initial variety trial conducted in commercial California orchards are beginning to bear fruit. However, fruit retention and yields are low due to excessive abscission during early fruit set. Horticultural techniques, such as plant growth regulator (PGR) sprays and girdling, often increase fruit retention and yield of fruit tree crops, though effects are typically dependent on treatment timing and PGR concentration. The objective of this study was to identify PGR and girdling techniques that result in increased longan fruit retention. The experiment was conducted in a commercial orchard using a randomized complete block design with whole-tree experimental units and five replications per treatment. Treatments included foliar applications of two synthetic auxins, 1-naphthaleneacetic acid (NAA) at 20, 60, or 100 ppm or 2,4-dichlorophenoxyacetic acid (2,4-D) at 5, 25, or 45 ppm, each applied during early or late fruit set. Girdling was also conducted at early or late fruit set, for a total of 15 treatments, including an untreated control. Factors examined at harvest included fruit number and mass per inflorescence and individual fruit mass and diameter. During the on-crop year, a significant increase in the number and mass of fruit per inflorescence was observed in response to 25 ppm 2,4-D applied at late fruit set, as compared to the control. Despite this increase in fruit number, 25 ppm 2,4-D applied at late fruit set did not result in decreased diameter and mass of individual fruit. Late fruit set applications of 25 ppm 2,4-D appear to mitigate the effects of alternate bearing in the off-crop year. Fruit abscission during early and/or late fruit set decreased in response to 5 ppm 2,4-D at early fruit set, 25 or 45 ppm 2,4-D at early or late fruit set, or 100 ppm NAA at early fruit set. Fruit loss occurred as a result of Santa Ana winds during both growing seasons. Neither leaf nor fruit nutrient concentrations of treated trees were significantly different from that of untreated controls. Results indicate that properly-timed PGR applications have the potential to be used commercially to increase yield and profit to longan growers in California.

Aflatoxin M1 (AFM1) is frequently found in milk and dairy products. It is a metabolite formed in cows from aflatoxin B1 (AFB1), contained in animal feeds. In cheese production AFM1 distributes between curds and whey. In this study, cows were fed 64 µg/AFB1/d for the high treatment, and 5 µg/AFB1/d for the low treatment, to obtain milk contaminated with AFM1 over the 0.5 µg/L and under 0.05 µg/L restrictions, respectively. Cheese was manufactured with milk contaminated with AFM1 at 0.8 and 0.03 ìg/kg by the higher and lower treatment, respectively. Two commercial cheeses were elaborated: a hard-aged cheese (cheddar cheese) and soft high moisture cheese (fresco cheese) to evaluate whether the cheese type had any impact on AFM1 analysis. AFM1 was extracted from cheese using immunoaffinity columns. Analyses were carried out by using high pressure liquid chromatography (HPLC) as the reference method and fluorometry as a method of validation. Analysis was by 2-way fixed factor analyses. AFM1 was detected in all samples by both methods of analysis. There were no detectable statistical differences between cheese types (P>0.05). AFM1 content was significantly different between the high and low concentration of AFB1 used to make the cheese type (P<0.01). Our regression model shows a linear relationship between fluorometry and HPLC methods; R2 = 0.9141 from cheddar cheese and R2 = 0.9141 from fresco cheese. There were no statistical differences between methods of analysis (P>0.05). Carryover of AFM1 in cheese detected by fluorometry in cheddar cheese was 163% and 80% for high and low treatments, respectively, and in fresco cheese was 119 and 133 for high and low treatments, respectively. These carryovers are below that reported in the literature. Results suggest that fluorometry is a simple and reliable AFM1 detection method for screening samples of complex matrices such as cheese.

Carrots (Daucus carota L. cv. Royal Chantenay) and sweet corn vi (Zea mays L. cv. Iochief) were grown rm the Utah State University's Greenville farm in 1969 and 1970. The soil was fumigated with Telone (a mixture of 1, 3-dichloropropene and other chlorinated hydrocarbons) at the rates of 10, 20, and 30 gal/acre and Nemagon (1, 2-dibromo-3-chloropropane) at the rates of 1, 2, and 3 gal/acre one week before planting. Samples of uniformly mature carrot roots were taken for the studies of total carotenes, β-carotene, total and reducing sugars, respiration, and ultrastructural changes; and those of sweet corn seeds for the studies of total carotenoids , starch, total sugar, and total nitrogen changes. Compared to the controls, carrots grown on fumigated soil had a significantly higher content of total carotenes, β-carotene, and total sugars, and a lower rate of respiration. The electron microscopic study indicated that the carrots from Telone (30 gal/acre) and Nemagon (3 gal/acre) fumigated soil had larger chromoplasts that contained more globuli and crystals than those of the controls. The soil fumigations with Telone and Nemagon also brought about the increase in total carotenoid content in sweet corn seeds.

The United States produces about 1.8 million tons of sugar annually. Approximately 75 per cent of this production is derived from sugar beets. The importance of the sugar beet crop in national and world economy is justification for research effort as a means to more economical production. It is desirable that sugar beet processing be carried out in the most efficient manner. More effective utilization of the sugar beet and its by-products will add stability to the sugar beet industry. For the past 170 years, since Achard found that sugar could be used for human consumption and that pulp might be fed to cattle, sugar processors have made limited use of the non-sugar constituents of the sugar beet. These materials have been disposed of almost exclusively as livestock ration supplements. The non-sugar constituents have been largely responsible for failure to extract all of the sugar from the beet (13). As a result they have been viewed with suspicion by most sugar beet processors. However, recent development suggest that the utilization of sugar beet by-products will constitute a more important phase of the sugar beet industry in the future. At this critical period in the sugar beet industry, it is difficult to overemphasize the need for a better understanding of the chemical constituents of the sugar beet and the effects of various physiological factors upon them. One of the non-sugar constituents of the sugar beet which has recently received attention is glutamic acid. This has been brought about primarily by the discovery that the salt, monosodium glutamate, has an enhancing effect upon the flavor and palatability of many foods. Using the sugar beet as almost the exclusive source of glutamic acid, a new industry (utilizing over 100 tons of beet molasses daily) has developed to manufacture and market this food seasoner (28). Preliminary investigations at the Utah Experiment Station (14) showed that of all the chemical constituents determined, glutamic acid was the most variable. This agreed with earlier work in this field (16, 42). Being highly variable this constituent is a chief contributor to difficulties in sugar processing. The purpose of this study was to determine the effect of some of the major agronomic factors, such as moisture, fertility, variety, and sampling date, upon the glutamic acid content of the sugar beet.

Arundo donax (Giant Reed) is quickly being developed as a rapidly-growing, robust, and highly productive bioenergy crop, with large scale cultivation of this species planned for the Columbia River basin of the Pacific Northwest (USA). Despite its potential as a next generation biomass crop, relatively few studies have examined the physiological performance of A. donax under agricultural conditions. Unlike traditional crops, A. donax is known to be a high-emitter of the volatile compound isoprene, which may significantly impact regional air quality, but it has not been widely cultivated in North America and little is known about how this species will perform in the Pacific Northwest. Over two field seasons, we measured isoprene fluxes from A. donax plants in both greenhouse conditions and in an agricultural field setting under a variety of conditions and fertilizer treatments. We also measured several other attributes of A. donax productivity and leaf physiology including chlorophyll content, photosynthesis rate, stomatal conductance, specific leaf mass, water use efficiency and gas exchange. We found that A. donax physiologically performs well under cultivation in the Columbia River basin, but that it also emits isoprene at significantly higher rates than previous reports indicate. We also found that both isoprene emission and leaf physiology were highly affected by agricultural management decisions, including nitrogen and irrigation management. Our findings indicate that crop management strategies can be developed that simultaneously seek to minimize isoprene emission while maximizing biomass production in this newly emerging bioenergy crop.

With new 2,4-Dichlorophenoxyacetic acid (2,4-D) tolerant crops, increases in off-target movement events are expected. New formulations may mitigate these events, but standard lab techniques are ineffective in identifying these 2,4-D formulations. Using Fourier-transform infrared spectroscopy and machine learning algorithms, research was conducted to classify 2,4-D formulations in treated herbicide-tolerant soybeans and cotton and observe the influence of leaf treatment status and collection timing on classification accuracy. Pooled Classification models using k-nearest neighbor classified 2,4-D formulations with over 65% accuracy in cotton and soybean. Tissue collected 14 DAT and 21 DAT for cotton and soybean respectively produced higher accuracies than the pooled model. Tissue directly treated with 2,4-D also performed better than the pooled model. Lastly, models using timing and treatment status as factors resulted in higher accuracies, with cotton 14 DAT New Growth and Treated models and 28 DAT and 21 DAT Treated soybean models achieving the best accuracies.

In Bolivia, tomato acreage is 6717 and has a yield of 12005 kg/ha and the total production is 80,636 TM. Departments that harvest tomato are Santa Cruz, Cochabamba and La Paz, Santa Cruz being the department that shows the highest rates of production with 40653 TM in comparison with La Paz which has a production of 3109 TM and Cochabamba of 2420 TM. The principle factors in affect are, the best climatic conditions in Santa Cruz, while Cochabamba and La Paz have differences in seasonal changes (National Institute of Statistics, 1998). The importance of the tomato harvest lies in consumption preference, for the nutritional properties, as they provide a rich source of Vitamins A and C, principally for its qualities of high productivity in terms of yield per area, being a factor of great importance in the economy of the farmer. The repeated production of tomato in the same area or locality tends to create problems phytopathologicals caused by fungi, bacteria and viruses, that at times become difficult to handle, thus becoming serious limiting factors that are able to seriously affect the yields, as such the investigation of sickness control is of extreme importance. The community of Carmen Pampa belonging to the municipality of Coroico, Nor Yungas, constituting a suitable area for the cultivation of tomato, but the attack of diseases caused by fungi, principally Phytophtora infestans, with an incidence of rate of 98%, which is increased by high temperature, humidity, precipitation and fog, all of which favor the spread of this fungus. For this reason farmers are forced to use chemical products that cause problems of resistance of the causal agent of the illnesses. The FAO (1992) estimates 3 million poisonings annually at a global level of farmers and families as a result of chemicals, which cause in turn a residual effect, environmental pollution and creates and additional cost in production. In the investigation of intoxication by agrochemicals in Bolivia, in a population of 870 persons studied mentioned that, 88% are unaware of the risks associated with the use and management of using them; the cases of poisonings are more frequent in tropical plains with 46%, the valleys with 26%, the inter-Andean valleys with 14% and the high plains with 12%, without mentioning those of suicide origin. For this reason, the object of the present investigation is to try to control the late blight disease (Phytophtora infestans) in the cultivation of the tomato (Lycopersicum sculentum), with biocides, to eliminate or diminish the use of agrochemical products.