One hundred and twenty lactating Holstein cows in mid-lactation were offered diets varying in protein level and degradability at two locations during hot and moderate weather. Treatments were: (1) High protein (19%), high degradability (65%); (2) High protein (19%), medium degradability (40%); (3) Medium protein (15.5%), high degradability (65%); (4) Medium protein (15.5%), medium degradability (40%). Diets were individually fed during hot weather at the University of Arizona Dairy Farm and contained 38.4% alfalfa hay, 12.4% cottonseed hulls, 9.8% whole cottonseed, and 39.4% concentrate (dry matter). Diets were group fed during moderate weather at the Brigham Young University Dairy Farm, Provo, Ut, and contained 31.3% corn silage, 14% alfalfa haylage, 9.4% whole cottonseed and 45.3% concentrate (dry matter). Average daily ambient temperatures were 35.1°C for hot and 26.8°C for moderate weather locations. Fat-corrected milk (3.5%, 2 x milkings) and milk persistency were lower for treatment 1 than other treatments. For the respective treatments during hot weather means were: 23.4, 26.6, 28.5, 28.4 kg/d; 83.2, 91.2, 90.9, 90.3%; and for moderate weather means were: (3 x milkings): 34.7, 31.8, 32.2, 32.4 kg/d; 97.0, 93.4, 92.1, 90.3%. Dry matter intakes during hot weather were 21.5, 21.9, 23.3, and 23.1 kg/d. Respiration rate and rectal temperature during hot weather were: 90.1, 87.9, 90.9, 94.7 counts/min; 39.0, 39.3, 39.3, 39.5°C and for moderate weather: 61.2, 58.2, 55.5, 67.4 counts/min; 38.8, 38.6, 38.7, 38.8°C. Serum T₃,T₄ and cortisol were generally unaffected by treatment, but were depressed during hot weather. Serum glucose was not significantly affected by treatments at either environmental locations. Animals consumed more water with highly degradable protein diets at each location along with consuming more water during thermal stress. These data show that 3.5% fat-corrected milk and milk persistency are significantly affected (P <.01; P <.025) by rations high in protein of high degradability during heat stress.

The sensitivity of Arizona-grown grapefruit to chilling temperatures varied throughout the harvest period studied. This sensitivity was high in October, decreased in November and December, then increased in February. In April and May there was another decrease in sensitivity to chilling temperatures. Coating fruit with vegetable oils or fats successfully delayed the development of chilling injury and reduced the degree of injury, however, vegetable oils applied as water emulsions were even more effective in preventing chilling injury to 'Redblush' grapefruit extending the period of marketability more than 100 days. Postharvest application of CaCl₂ and certain plant growth regulators significantly increased the resistance of 'Marsh' grapefruit to chilling injury, but less so than oil emulsions. Scanning electron microscope photomicrographs of 'Marsh' grapefruit peels showed that severe chilling injury was a depressed area of collapsed cell, just beneath the epidermis layer. As the severity of chilling injury increased, non-collapsed cells gradually increased in size. Cell walls were irregularly shaped; thin in some areas and thick in others. Oil glands in depressed areas were not ruptured during cold storage. Hence release of toxic materials through rupturing of oil glands is not a factor in chilling injury. Compared to non-injured tissue, injured tissue from the same fruits had significantly lower water and osmotic potentials, and low, near zero, turgor pressures. There was a significant negative correlation (r = -0.5; p < 0.05) between the water potentials of the peels and the percentage of 'Marsh' grapefruit with severe chilling injury during storage at 2.8C. Ion leakage tended to increase during cold storage, and when the fruit were transferred to room temperature. Internal conductivities declined sharply during cold storage and then increased very strongly during periods at room temperature.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

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The paper presents an investigation of the possibility of using dendrochronological methods in determining the degree of the adaptation of spruce stands to the given site conditions. The results of the investigation were statistically evaluated. The results obtained may be of use for the problem of the selection of trees species suitable for specific ecological conditions.

<p>U okviru disertacije ispitivan je uticaj sorte i mikroklimatskih uslova tokom dve proizvodne godine p&scaron;enice na sadržaj i strukturu albumina; izvr&scaron;ena je karakterizacija albumina pomoću Lab&ndash;on&ndash; a&ndash;Chip elektroforeze; određena je aktivnost proteolitičkih i amilolitičkih enzima, sadržaj slobodnih sulfhidrilnih i slobodnih amino grupa; ispitana su reolo&scaron;ka svojstva testa primenom uobičajenih metoda za procenu tehnolo&scaron;kog kvaliteta bra&scaron;na i izvedena je karakterizacija gotovog proizvoda-hleba. Jedan deo istraživanja se odnosio na period posležetvenog dozrevanja p&scaron;enice i stabilizacije bra&scaron;na.<br />Obe ispitivane godine odlikovao je toplotni stres s tim &scaron;to su u 2012. godini maksimalne<br />temperature prelazile 35 &deg;C i broj tropskih dana je bio izrazito veći u odnosu na 2011., &scaron;to je uslovilo promene u sastavu i kvalitetu proteina i skroba u zrnu p&scaron;enice. Sadržaj ukupnih albumina uzoraka p&scaron;eničnog bra&scaron;na iz 2012. bio je značajno manji u odnosu na 2011. proizvodnu godinu. Rezultati određivanja proteolitičke i amilolitičke aktivnosti uzoraka p&scaron;eničnog bra&scaron;na iz dve proizvodne godine su pokazali da su za 2012. proizvodnu godinu karakteristične znatno niže vrednosti ovih pokazatelja u odnosu na 2011. proizvodnu godinu i da je enzimska aktivnost pre svega sortna karakteristika.<br />Sadržaj slobodnih sulfhidrilnih grupa uzoraka p&scaron;eničnog bra&scaron;na iz 2012. proizvodne godine bio je značajno veći dok je sadržaj disulfidnih veza bio manji u odnosu na 2011. Sadržaj slobodnih amino grupa se razlikovao između uzoraka iz dve proizvodne godine, kako između različitih sorti, tako i u pogledu sva tri primenjena tretmana inkubacije glutena. Značajne razlike između vrednosti slobodnih amino grupa izmerenih nakon inkubacije gluten na 37 &deg;C, ukazuju na različitu proteolitičku aktivnost ispitivanih uzoraka p&scaron;eničnih sorti. U poređenju sa uzorcima iz 2011. proizvodne godine, uzorci iz 2012. su imali znatno niže vrednosti specifične zapremine hleba.<br />Dodatkom dvostruke količine sopstvenih albumina odabranom setu uzoraka dobijeni<br />su rezultati, koji ukazuju da su uzorci bra&scaron;na iz 2011. imali manjak amilolitičkih enzima, a uzorci iz 2012. manjak proteolitičkih enzima za postizanje optimalnog tehnolo&scaron;kog kvaliteta.</p> / <p>In this dissertation, the influence of variety and microclimatic conditions that prevailed during the two production years on the content and structure of wheat albumins were investigated; characterization of albumins was performed by Lab-on-a-Chip capillary electrophoresis; the proteolytic and &alpha;- amylolytic activity, as well as the content of free sulfhydryl and free amino groups were also determined; the rheological properties of dough were estimated using conventional methods for the assessment of flour technological quality and characterization of the final product- bread was performed. One part of the research covered the period of postharvest wheat and flour maturation. Heat stress was characteristic of both production years; however, in 2012, maximum temperatures exceeded 35 &deg;C and the number of days with maximum temperatures above 30 &deg;C was markedly higher than in the 2011 production year. These conditions have caused the changes in the composition and quality of protein and starch in wheat kernels. The albumin content of wheat flour samples from 2012 was significantly lower compared to 2011 production year.&nbsp;Results of proteolytic and amilolytic activities of wheat flour samples from two production years, showed that the values of these indicators were significantly lower for 2012 in relation to the 2011 production year, and that the enzyme activity is primarily varietal characteristic. The content of free sulfhydryl groups of wheat flour samples from the 2012 production year was significantly higher while the content of disulfide bonds was lower than in 2011. The content of free amino groups differed between samples from two production years. Differences in the amount of free amino content were evident between the varieties and between different treatments of gluten incubation. Significant differences between the values of the free amino groups measured after gluten incubation at 37 &deg;C, indicate a different proteolytic activity of tested wheat flour samples. In comparison with the samples from the 2011 production year, samples from 2012 had significantly lower values of specific bread volume. The addition of double amount of its own albumins to the selected samples indicated&nbsp;that the flour samples from 2011 had a deficit of amylolytic enzymes and samples from 2012 had a deficit of proteolytic enzymes for achieving optimal technological quality.</p>

M.Com. (Financial Management) / This paper investigates the use of weather derivatives in the maize production industry of South Africa. The history, users and mechanics of weather derivatives and maize production are presented in the study. This study examines, by using experiential design, the potential revenue for a control and a test group of farmers using monthly, actual maize production and weather observations for the period 2000 - 2010. This study suggests, with reference to the results, an option strategy that ultimately results in the hedging of maize output risk for the farms investigated. Limitations of the study are basis risk, liquidity, the difficulties in pricing of the weather derivative and finally the reticence of agricultural business to explore these hedging instruments in practise. In conclusion the study presents suggestions for further research into the wider application of weather derivatives into other industries, the exploration of the effects of weather on changes in crop yield and the effects of a hybrid maize crop and its possible resilience to weather changes. This study also demonstrates the weather effects on maize output and suggests a hedging solution to yield.

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No description available.

The CO2 concentration in the atmosphere is rising dramatically each year. Increases are certain to influence growth of C3 plants. This thesis focuses on the growth and development of rice (Oryza sativa L. cv. Jarrah).The major questions addressed in this thesis were whether elevated atmospheric CO2 concentrations would : 1/ increase grain yield where the soil was flooded or unflooded under conditions of varying phosphorus supply; 2/ change the timing of development; 3/ alter the partitioning of dry weight and nutrients between the roots and shoots; and, 4/ influence grain quality. The mechanisms underlying growth and developmental changes at elevated CO2 were also investigated. After experimentation, it is concluded that the grain yield of rice will increase as the atmospheric CO2 concentration rises even when phosphorus supplies are low. The largest response to rising atmospheric CO2 concentrations will occur under dryland conditions but increases of up to 60 per cent are likely in flooded rice. Importantly, there is likely to be a reduction in the life cycle of rice crops as the CO2 concentration rises. This would have the advantage that more crops could be sown in one season. The quality of the rice grain produced at high CO2 concentrations will also change, with milling quality appearance likely to improve. The cooked rice will be firmer. Experiments also showed that rice grown in flooded soil at different CO2 concentrations is an excellent system for investigating the control of plant growth and development, particularly the influence of hormones. / Doctor of Philosophy (PhD)