Ph.D. / This study investigates the relevancy of the current Agricultural Science curriculum for the Senior Secondary school phase. It also surveys whether the syllabus addresses the needs of the world of work in the agriculture community. The process of curriculum development for compiling the current syllabus within the context of a new South Africa is evaluated and proposals made in order to make it more democratic and to make participation an important principle at all levels of the development process ...

Bunt is a serious disease of wheat found in nearly all weat-growing countries of the world. In India the disease is more severe in the northern provinces than in the central and southern provinces as the temperature during planting time is favorable to the germination of the fungous growth in the northern part. In the central or southern parts, this is not the case. In the United States this disease causes heavy annual loss. The amount of smut in a field, or the percentage of smutted heads, is generally taken as an index of the reduction in yield or loss from the disease, i.e., with 10 percent of all heads smutted, the loss would be estimated at 10 percent. It seems probable, however, that the loss is not quite equal to the percentage indicated by the smutted heads, since smutted plants are generally weaker than adjacent healthy plants which consequently stool more heavily and tend to occupy the space. With higher percentage of smut, the less or reduction in yield is more nearly equal to the percentage of smutted heads.

Present-day plant breeding, on the foundation made many years ago, has achieved important scientific and economic results. By means of introductions and selections, superior strains such as Turkey and Kanred have been obtained. Through hybridization new combinations of characters result, combining desireable characters of different plant types in a single individual. In this program, wheat hybridization has occupied a worthy place. Each year a numbero f wheat crosses are made at the Utah Experiment Station, the main purpose of which is to develop superior strains of wheat. Such an economic program is aided and hastened by studies in genetic behavior. This paper reports such a genetic study of the inheritance of awns, spike density, and kernel color in a cross between Ridit and Utac wheat varieties.

Soil samples taken from a clearcut and adjacent uncut site of a Douglas Fir and Western Hemlock old growth forest in the Cascade Range of southern Washington showed greatly reduced adult and juvenile population densities of macro-phytophagous, microphytophagous, and predatory soil acari in the clearcut. These effects appeared to be due to high lethal summer litter temperatures and reduced pore spaces due to scarification. Also, the number of species of acari in the clearcut was lower than in the control after clearcutting.

In the late nineteenth century most dairy farmers went about their work in much same manner as had their predecessors centuries earlier. However, by 1940 most farmers practiced recognizably modern dairying techniques. Use of mechanical milking machines was widespread and growing, farmers compounded rations by combining feeds that blended precise proportions of proteins, carbohydrates, fats, and vitamins, and breeders, eager to maximize the influence of productive bloodlines, evaluated their animals with the use of scientific scorecards and employed intense breeding plans that relied on various forms of inbreeding in order to fix the desirable aspects of prized cattle. Yet the majority of these changes were instigated not by the dairy farmers who actually performed the tasks but by agricultural scientists working in the laboratories of the nation’s agricultural colleges and experiment stations. Agricultural science emerged in Germany in the 1840’s; Americans pursuing advanced degrees in Europe brought these ideas to the United States War and received an official imprimatur with the passage of the Hatch Act in 1892, which dedicated federal funds to the establishment and maintenance of agricultural experiment stations. The focus of this study is the work performed by these scientists in shaping the development of American dairy farms between 1890 and 1940. Researchers not only made scientific advances, such as the discovery of vitamins, that led to new methods of feeding and breeding dairy cattle but also invented and evaluated technological advances such as the Babcock Milkat test and mechanical milking machines that would revolutionize American dairying. This work contributes to our understanding of the emergence of the modern dairy farm by demonstrating that it was agricultural scientists, more so than farmers, who established the outlines of the modern dairy. They did so not only by adopting common techniques and methodologies that fostered communication and cooperation between and among researchers but by employing a number of rhetorical devices that broke down the barriers between laboratory and farm. While farmers enjoyed the benefits of scientific advances, they did so at the cost of their autonomy as scientists increasingly dictated what constituted modern dairying.

Drönarteknik inom skogsuppskattning blir allt vanligare. Klave har alltid varit det vanliga verktyget att använda för diametermätning i brösthöjd av träd. Ny teknik har gjort det möjligt att mäta brösthöjdsdiameter genom att filma träden med drönare. Från filmen skapas ett skalenligt tredimensionellt punktmoln där brösthöjdsdiameter kan utvinnas, processen kallas för videogrammetri. Denna studie undersöker precisionen hos diametermätning genom videogrammetri från drönare.

I skogsplantskolor har styrolit länge använts som täckmaterial på nysådda plantor. Styroliten skyddar fröet och gör så att torven behåller fukten bättre. Styrolit har en baksida, det är ett icke förnybart material tillverkat av olja och materialet följer med plantorna ut i skogen. Ersättare för styrolit finns men dess effekt på plantproduktionen är inte helt kartlagd. Syftet med denna studuie var att jämföra effekterna av styrolit och sågspån som täckmaterial och se vilken påverkan de har på grobarhet, tillväxt och vitalitet. Resultatet av studien visade att täckning med sågspån gav en bättre total grobarhet än täckning med styrolit. Studien visade också att höjdtillväxten hämmas av ett tjockare sågspånslager. Indikationer fanns på att grövre fraktioner av sågspån gav bättre tillväxt hos tall än täckning med finare fraktioner.

Potassium (K) deficiency of soybean [Glycine max (Merr.) L.] is common throughout the Mid-Southern region of the United States. Visual symptoms of K deficiency may be absent or subtle during early and mid-reproductive growth stages. Correcting K deficiency in-season is problematic due to limited research. Information regarding soybean yield response to in-season fertilizer K application time is limited to growth stages prior to the onset of R1. Research is also limited on new higher yielding soybean cultivars. The objective of this study was to evaluate influences of in-season K application timing during reproductive growth stages on soybean yield. Field experiments were established in 2019, 2020, and 2021 to evaluate the effect of soybean potassium rate and timing during reproductive growth stages. Four independent experiments were established to: (1) determine the effect of applying K fertilizer to sufficient soils at different times in-season on yield and plant K status on two different soil textures, (2) determine the effects of K timing, K rate, and dicamba rate on yield and plant stress, and (3) determine the effects of K timing and desiccation on yield and plant stress. Results indicate that potassium application rate and timing during soybean reproductive growth stages do not increase yield on soils with adequate K present. Soybean trifoliate leaf tissue K analysis and petiole sap K analysis had no response during reproductive growth stages when K fertilization occurred on soils with ample K. Potassium fertilization did not aid soybean recovery after dicamba injury.

The population on earth is continuing to increase and a higher food production is needed to maintain this population. However, the food production system is changing and one of the changes is the start implementation of urban food production systems. Even though these types of systems have benefits compared to conventional farms it is important to further investigate how these can be optimized to reduce the total environmental impact at the same time as a more resilient food production system is created. Two separate systems were observed, one a vertical farm cultivating lettuce and the second one an urban farm cultivating oyster mushrooms, to later investigate possible synergies if viewing the two systems as one. Four synergies were identified; “Carbon dioxide cycling”, utilizing “Organic waste”, utilizing “Spent mushroom substrate” and “Light transfer”. All synergies variation in potential environmental impact reduction with the largest overall potential in synergy three - utilizing spent mushroom substrate as growth medium in the vertical farm. / Befolkningen på jorden fortsätter att öka och en högre livsmedelsproduktion behövs för att upprätthålla denna befolkning. Livsmedels produktions systemet håller dock på att förändras och en av förändringarna är implementeringen av urbana livsmedels produktion system. Även om dessa typer av system har fördelar jämfört med konventionella gårdar är det viktigt att ytterligare undersöka hur dessa kan optimeras för att minska den totala miljöpåverkan samtidigt som ett mer motståndskraftigt livsmedels produktions system skapas. Två separata system observerades, första är en vertikal odling som odlade sallad och det andra var en urban odling som odlade svampen ostronskivlingar. Dessa två system undersöktes senare för att identifiera möjliga synergier om man ser de två systemen som ett. Fyra synergier identifierades; "Koldioxid cykling", användning av "Organiskt avfall", användningen av "Använt svamp substrat" och "Ljusöverföring". Alla synergier varierar i potential för att minska miljöpåverkan med den största totala potentialen i synergi tre - utnyttjande av förbrukat svamp substrat som odlingsmedium i den vertikala odlingen.

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