Reactions of in vitro pollen-pistil combinations were studied and related to compatibility differences in Buffalo alfalfa Medicago sativa L.) at Western Kentucky University, Bowling Green. Pollen-pistil combinations were made at random among a number of alfalfa plants in 1968 (Experiment I). Pollen tube elongation varied significantly when -4 pollen from the same plant was placed on agar media containing pistils from different plants. Three of four plants for which intra-plant combinations (pollen and pistils from same plants) were made 1,ad tube lengths significantly shorter than those measured for inter-plant combinations (pollen and pistils from different plants). Similar in vitro pollen-pistil combinations were made in 1969 (Experiment II) with another group of Buffalo alfalfa plants. When grouped according to pollen source, significant differences were found among tube lengths for different combinations within most groups. Intra-plant combinations for four plants gave varying tube lengths and were inconsistent in their rankings relative to inter-plan combinations within groups. Within a pollen source. mean pollen tube lengths were consistently longer on the control medium, with no pistils present, than on the medium containing pistils. Twenty-two crosses and selfs were made which were analogous to the pollen-pistil combinations in Experiment II. The self- or cross-compatibility was determined by three indexes: percentage of flowers producing pods, seeds per flower, and seeds per pod. Correlation coefficients were not significant for percentage viable pollen or mean pollen tube length versus each of the three indexes. However, the correlation coefficients were positive and relatively consistent for the two pollen characteristics versus the three compatibility indexes.

The effects of chemical additives on the fermentation pattern and subsequent feeding value of corn silage was investigated over a two year period. Corn plants harvested in August 1967 (Experiment I) were ensiled with no additive, 3.50 per cent area, or urea-mineral mix supplying an equal amount of urea. Those harvested in August 1968 (Experiment II) were ensiled with no additive, 0.50 per cent urea, or 0.75 per cent urea. The nutritive value of these silages was evaluated chemically and by lactation trials. :he addition of urea alone, or in combination with minerals elevated the initial pH and buffered against reduction of pH during fermentation. Urea-mineral combination exhibited a stronger buffering action than urea alone. Data obtained during the first 25 days of fermentation in Experiment II indicated that acetic acid essentially completed after 5 days. Lactic production was acid production continued throughout the 25-day period. The production of propionic, butyric, and lactic acids was significantly increased by increased amounts c: urea (P<.01). Acetic acid production was significantly increased (P<.01) by the addition of 0.75 per cent urea but was slightly, although not significantly, depressed by the addition of 0.50 per cent urea. In both experiments the treated silages tended to have less crude fiber, ether extract, and nitrogen-free-extract, but more ash and crude protein than the control silages. The crude protein content appeared to be elevated in an amount corresponding to the amount of urea added. The effects of fermentation on urea were studied in Experiment II. Approximately 72.7, 65.3, and 66.6 per cent of the initial nitrogen as urea in the control, 0.50 per cent urea, and 0.75 per cent urea silages, respectively, was converted to other forms. The increase in NH 3 -N accounted for 22.8, 44.4, and 24.8 per cent of this decrease in urea-N in the control, 0.50 per cent urea, and 0.75 per cent urea silages, respectively. In the lactation trials, 24 Holstein cows were arranged In a 3 x 3 Latin Square design. Experimental silages were fed ad libitum. The diets were isonitrogenous and isccaloric. No significant difference was noted in milk production, silage consumption, and body weight change between COWS fed the control and 0.50 per cent urea silages in both experiments. Cows fed the urea--ineral silage in Experiment I, produced significantly less milk, consumed significantly less silage, and gained significantly less body weight than did cows fed the control and 0.50 per cent urea silages (P<.01, P<.01, P<.05, respectively). In Experiment II, cows fed the control and 0.50 per cent urea silages consumed significantly more silage dry matter than cows fed the 0.75 per cent urea silage (P<.01). Cows fed the control silage gained significantly more weight than did those fed the 0.75 per cent urea silage (P<.05), whereas, cows fed 0.50 per cent urea silage were not different from either the control or 0.75 per cent urea group in this respect. No significant differences in FCM production were noted among treatment groups.

Research was undertaken in the summer of 1989 to determine the effect of phosphorus placement on the yield and quality of field grown tomatoes Lycopersicon esculentum. A subsequent study was undertaken in the winter of 1989 to determine the effect of phosphorus rate and placement on the early growth and phosphorus uptake of young tomatoes in the greenhouse. The purpose of this study was to attempt to find the most efficient placement and rate of supplemental phosphorus when growing tomatoes. It has been shown that placing phosphorus in a concentrated zone in contact with plant roots results in more growth and fruit yield. The current trial involved the application of phosphorus at different rates and use of different methods of application. The methods of application included broadcasting phosphorus, placing phosphorus in a concentrated band, and combinations of the two. It is of great interest to the tomato producer to know the most efficient rate and placement of fertilizer phosphorus. Availability of phosphorus is necessary for the proper development of the tomato and a good supply is needed for adequate yield and quality. If improved application methods are developed, perhaps higher yields and improved fruit quality can be realized. This could possibly result in higher production for the producer and more satisfaction for consumers. The results of the field study were not statistically significant. One reason for the lack of any yield response was the greatly reduced yields caused by hail damage and fungal disease. Surprisingly, the greenhouse study showed that significant growth increase resulted from phosphorus broadcast treatments. One explanation may be the small volume of soil used in this study. The plant roots were distributed throughout the entire soil volume in contrast to the situation with widely spaced field grown tomatoes. Thus, the broadcast treatments achieved more root-fertilizer contact in the greenhouse pot cultures.

The effects of cultivars and plant spacings on biological yield, seed yield, seeds per pod, average seed weight, and harvest index of beans (Phaseolus vulgaris L.) were studied in 1987 and 1988. Two cultivars, 'Blue Lake 27' and 'Kentucky Wonder 125' and four plant spacings -- 7, 14, 21, and 28 cm, constituted eight treatments that were arranged in a split-plot with four replications. Each experimental unit or hill consisted of five plants -- four in the corners and one in the center of a square. Spacings treatment were established by varying the distance between the center plant and the four corner plants. Corner plants provided competition; only the center plant was harvested for experimental data. The data were subjected to analysis of variance procedure for a split-plot design, assuming a fixed model. The cultivars had similar biological yield curves during the 1987 growing season and did not differ significantly for biological yield at the final harvest either year. Kentucky Wonder 125 produced significantly higher average seed weight and harvest index, but fewer seeds per pod, than did Blue Lake 274. In 1987, seed yield per plant was higher for Blue Lake 274 than for Kentucky Wonder 125; however, the cultivars did not differ significantly for seed yield per plant in 1988. Spacing treatment effects were not significant when expressed through seed yield per plant, seeds per pod, average seed weight, or harvest index. Spacings affected biological yield significantly in 1988, but not in 1987. The linear response of biological yield to spacing was positive and significant both years. The linear effect of spacings on pod yield was significant in 1988, but not in 1987. Drought conditions in 1987 and 1988 adversely affected bean growth and seed production. The experimental error, as evidenced by large coefficients of variation for treatment means, was unusually high. Consequently, some true cultivar and spacing effects may not have been detected.

With the introduction of herbicide resistant Palmer amaranth into Kentucky during the past 10 years there has been an increasing concern for effective control measures in grain production. Field trials were performed in 2016 and 2017 near Barlow and Paris, KY to determine efficacy of chemical control programs targeting herbicide resistant Palmer amaranth. Percent visual control, effects on plant density and plant height were measured in 2016 to determine treatment effectiveness. Treatments containing four different sites of herbicide activity achieved an average of 98% control. Treatments containing only 3, 2 or 1 site of activity only achieved 64%, 45% and 33% control, respectively. Within the long-chain fatty acid inhibitors herbicides in this study, pre-emergent applied pyroxasulfone provided greater control than S-metolachlor or acetochlor. Pyroxasulfone also provided greater control than the photosystem II herbicides atrazine and metribuzin. In 2017 PRE treatments consisting of three-way mixtures of flumioxazin + pyroxasulfone + chlorimuron or S-metolachlor + metribuzin + fomesafen followed by a POST herbicide treatment provided > 90% suppression of Palmer amaranth 4 weeks after trial initiation. Post-emergence treatments containing glyphosate + dicamba or glyphosate + 2,4-D following a soil-applied pre-emergent treatment achieved the most effective season-long control of Palmer amaranth.

Soybean yield differences are a combination of the genotype, environmental conditions, and management practices. Understanding how these factors interact through the analysis of the components involved in yield determination, provides a way to increase potential and actual yields in Kentucky. Two irrigated experiments were conducted to quantify differences in the mechanisms of yield determination across soybean maturity groups (MG) 2 to 5 (Chapter 1), and to quantify management options (seeding rate and choice of MG cultivar) that increase yield potential of double crop soybean systems (Chapter 2). Results showed that cultivars used different physiological strategies to achieve high yields, but these were not always consistent across the environments studied. High yields were often associated to a higher efficiency partitioning biomass to seeds that lead to a higher seed number in some cultivars, as well as associated to low seed growth rates (Chapter 1). The choice of MG cultivar had a greater impact on double-crop soybean yields than increasing seeding rates from 40 to 54 seed m-2. The higher seeding rate increased yields by 5% without an interaction with cultivar. Optimal MG choices for double-crop soybean in KY were dependent on the environment.

Large sums of money are spent annually for herbicides to control weeds in fall sown wheat. Many of these weeds are killed by such treatments while others survive and mature seed. Viability of seeds produced by weeds injured by systemic or growth regulator type herbicides has long been a matter of great interest, much speculation, and very little research. Data on this subject are needed in order to intelligently use chemicals for weed control.

Many problems of management of irrigated soils require a knowledge of the soil moisture status and its relationship to plant growth before they can be solved.

Two methods of crop improvement are open to the plant breeder. Pure-line selection, which might be mentioned first, deals with the natural variability in plant populations. Thru selection, isolation, and comparative yield tests superior individuals are located. Nothing, however, can be added which the plant does not already have. Here hybridization provides a new starting point. Increased variation, new combination of characters, and thus greater opportunities are provided for improvement. The present investigation has for its purpose a study of the latter phase of this subject. In certain parts of Utah the straw from dry-land wheat is used for feeding of cattle and horses. Turkey, the chief variety grown, is bearded in character. Some stockmen claim that the beards are not a disadvantage in feeding, but the majority of feeders favor straw free from this disagreeable feature. Heading and threshing outfits also make considerable complaint when handling Turkey. In fact, certain outfits have experienced difficulty in keeping men on Turkey jobs if any other work could be obtained. Yet, in spite of this fact, Turkey continues to be the predominating variety because of better quality which is reflected in the prices, and in addition higher-yielding power. So in contemplation of this situation it was deemed advisable to attempt crossing Turkey and others of the Crimean group with other winter wheats somewhat lower in quality and yielding power, yet having the desirable character of beardlessness. The bearded wheats, Turkey, Armavir, Beloglina, and Kharkov, were selected for the qualities of high yield, good milling, and drought resistance. Kofod and Gold Coin were chosen for the character of beardlessness. The aim in making the crosses was to determine the possibility of combining the desirable characters of these wheat types in single individual plants. While detailed genetic data were taken of the F1 and F2 plants, this work was only incidental to the main reason given for the crossing, except as it was of value in predicting and interpreting results.

Until the beginning of the present centry the general opinion was that Egypt and Mesopotamia were the earliest homes of cultivated plants. Recent translations of the old Chinese records, however, reveal the fact that many of our cultivated plants were grown by the ancient peoples of China prior to the time of the Egyptians. Dettweiler (11) (1914) writes: "Today it is admitted--except by a few--that the original home of the primitive European population, the Indo-Germans, is not Asia but northern Europe, that they developed their culture there in the late stone age, and that they then dispersed in their wanderings to the South and East as far as India." In some of the Swiss ruins of the ancient Lake Dwellers of the Neolithic age have been uncovered evidences of a highly advanced culture and several varieties of our cultivated plants 2000-4000 years B.C. Among them were found a short-eared, six-rowed barley, a two-rowed barley, small Lake Dwelling wheat, a true Binkel wheat, Egyptian or Indian wheat, Emmer, Einkorn, Meadow Millet, Club Millet, and Flax, although this is one of the present wild types. In another place the same varieties plus a few others and what appeared to be apple seeds were found. One thing seems evident, that is, some of our cultivated crops were grown by ancient peoples long before they made any record of it.