Alfalfa is the most important forage crop in the United States and a crop vital to the livestock industry. It is the ideal to which other hay crops are compared. In terms of total digestable nutrients and as an economical source of these nutrients, it is without equal. Other reagures in which alfalfa excels over other hay crops as a forage are: high yield, palatability, high protein and calcium content, and value as a source of vitamins A and D. Inaddition it has great falue in soil conservation practices for controlling erosion losses and nitrogen depletion. It also fits well in crop rotation plans. In Utah alfalfa is grown on more acres than any other crop except wheat. The objectives of this study are to: (1) determine the cost of producing alfalfa seed in the major producing areas of Utah for 1952; (2) determine the physical inputs necessary in alfalfa seed production; (3) determine the relative efficiencies of the various cultural methods; and (4) attempt to measure relative advantages or disadvantages of producing certified seed as compared to non-certified seed. There is a dearth of information on the economic aspects of alfalfa seed production in Utah and growers have requested the utah Experiment Stateion to compile cost and marketing information on the commodity. The opinion has been expressed that information of this type will aid the growers with their economic problems concerning alfalfa seed.

Application of fertilizers to soils to increase production yields has raised questions concerning the effect of fertilizer on chemical composition of plants. With the development of accurate, sensitive microbiological methods for the determination of amino acid in protein, speculations concerning amino acid content have been supplanted by acquisition of facts.

For many years seed growers have thought that definite relationships existed between seed production and the weather. When this subject is approached there is little unity of opinion, even among neighboring seed growers. This lack of unity would indicate that growers generally are aware of some cause which affects seed setting, but they are not certain that any particular condition of the weather is the chief contributing factor. Scientific writers1 on the subject are also confident that weather is probably one of the major factors influencing seed production.

Fine structural analyses of host tissue (alfalfa, Medicago sativa L.) response to infection by the stem nematode (Ditylenchus dipsaci Kühn) were conducted. Hypocotyl regions were taken on 1,3 and 7 days after inoculation. Electron micrographs of infected tissue indicated the types of damage were the same between Lahontan (tolerant line) and Ranger (susceptible line). Only the infection rate (in percent) and degree of damage were different between lines and among the different temperatures (15, 20 and 25 C). The higher the temperature, the more injury resulted. After 3 to 7 days of infection, the symptoms observed were swelling and broken endoplasmic reticulum (ER), distended and broken chloroplasts, loss of nuclear material and bulging and rupturing of nuclear envelopes. Heavily infected cell walls showed more osmiophilic substances on one side. Infected cytoplasm contained more ER (both rough and smoothER), ribosomes, vesicles and Golgi apparatus, suggesting increased metabolic activities. Lobing nuclei were observed in all treatments. Lipid content varied with temperature in one-day-old seedlings. At 15 and 25 C, electron dense substances were commonly found along the tonplast, intercellular spaces and on the cell wall. Also some enlarged ER were noted in the non-infected controls at these temperatures. From the fine structural studies of host tissue it is not possible at this time to determine the nature of resistance of alfalfa lines to nematode infection. More studies at both the biochemical and electron microscopical levels are needed. Further, studies on the activities of the nematodes at the various temperatures during the infection periods would be primarily important.

A few researches have been concerned with the structure and pollination of alfalfa flowers. Others have considered the biological problems concerned in the pollination and fecundation of the flowers. In none of these studies, however, has an attempt been made to follow carefully the alfalfa flowers through various stages of development. Nor has any effort been made to determine what effect the condition and duration of these stages may have upon the resulting seed crop The work that follows is a study of the changes through which the alfalfa flowers pass during the season while functioning as organs of seed production. Special effort has been made to study the condition and duration of the stages as they are related to the subsequent seed crop.

The plasmids pDN211 and pDNll, isolated from the gene bank of the Rhizobium japonicum strain I-110, have been reported to complement two different Nif+ Hup· (nitrogen fixation positive and hydrogen uptake negative) mutants. A 5.9-kb Hindiii DNA fragment of the cosmid pHU52, isolated from the gene bank of R. japonicum strain 122DES, has been reported to code for the two polypeptide subunits of uptake hydrogenase. To determine homology between the structural genes of uptake hydrogenase of the two strains, a Southern blot of the Hindiii restriction fragments of the plasmids pDN211 and pDN11 was hybridized to the 5.9-kb Hindiii fragment. A 6.0-kb HindIII DNA fragment of pDN11 was observed to be homologous to the hup DNA probe. Thus, the hup genes of the two Rhizobium strains are conserved. Colony hybridization with the 5.9-kb DNA as the probe was used to detect the homologous hup genes in alfalfa-, chickpea- and pigeonpea- Rhizobium species. These Rhizobium species were also successfully derepressed for uptake hydrogenase in free living conditions. It was found that 30% of the alfalfa-, 30% of the chickpea- and 21% of the pigeonpea- Rhizobium strains tested were Hup+ as determined by the methylene blue (MB) reduction assay. All but one strain of alfalfa- (Celpril Ind. 3623) and one strain of pigeonpea- Rhizobium (IC3282) that showed strong homology to the hup DNA probe also exhibited MB reduction activity. The Hup+ strains of alfalfa- and pigeonpea- Rhizobium produced significantly higher yields as compared to the Hup- strains, whereas those of the chickpea-Rhizobium strains produced significantly lower yields as compared to the Hup- strains. Two of the alfalfa-Rhizobium strains, USDA1024 and CmRm~, exhibited Hup activities greater than any reported previously for this bacterial species. The cosmid-borne hup genes of R. japonicum were successfully expressed in all strains tested but the enzyme activities were very low in alfalfa-Rhizobium compared to those in chickpea- and pigeonpea-Rhizobium species. The relative efficiency of N2-fixation was significantly increased by the transfer of hup genes into the chickpea- and pigeonpea- Rhizobium strains.

A 2 x 3 x 2 factorial arranged split plot experiment was used to determine the decrease of dry matter yield from field-dried alfalfa hay caused by the application of a measured quantity of artificial rain (sprinkling irrigation). The three hay treatment factors were (1) alfalfa hay was cut at late vegetative and early bloom stage of maturity and (2) leached by 0, 5 mm or 20 mm of artificial rain applied by sprinkling and (3) sprinkled in the swath, 24 or 48 hours after cutting. Changes in dry matter yield were not significantly (P<.05) related to stage of maturity of forage, level of artificial rain applied or the time of application of artificial rain. There were no significant interactions for dry matter yield. The non-significant interactions for dry matter yield. The non-significant results were probably due to the variability of the alfalfa stand among the specific areas harvested for each treatment and insufficient replications to control the variability. Forty-eight lambs were fed for 56 days on the twelve experimental hays with four lambs (replications) per treatment. The 56 day feeding period was split into four 14-day pen-type feeding periods. (1, paired feeding in pen; 2, individual feeding in pen; 3, individual feeding in cage; and 4, paired feeding in pen.) There was no significant response of the lamb to alfalfa hay quality (feed intake, weight gain or feed efficiency). Lambs increased feed intake when fed individually compared to pair feeding. The result was increased weight gain and feed efficiency of individually fed lambs. This was particularly evident during period two. There was a significant (P<.05) increase of feed intake associated with advancing maturity of forage during the individual pen feeding period. Feed intake was higher during the second paired pen feeding period relative to the first paired pen feeding, but lower than the single pen feeding. Lambs consumed the rain damaged hay as well as or better than the control hay when fed individually. The also gained faster with the greater feed intake. These results show that sheep will utilize rain leached hay efficiently if it is not heat damaged. The complication of heat damage needs additional study.

The use of F1 hybrids for commercial production of such cross-pollinated crops as corn, sorghum, sugar beets, onions, and pearl millet suggests the feasibility of using this technique for alfalfa. Production of F1 hybrids of commercial value is dependent on the use of breeding material expressing good combining ability. In order to obtain precise estimates of combining ability for quantitative characters in alfalfa, it is necessary to produce all possible single crosses among a number of parents. The single cross seed required is difficult to obtain due to the vegetative reproduction and isolation required; and, subsequently, limited testing of this type has been conducted in alfalfa. Testing breeding material for combining ability based on seed production has been more limited than testing based on forage yield or various other measurements. In this experiment a diallel crossing system was used to test the general and specific combining ability of five alfalfa clones previously selected for good general combining ability. The report is based on first-year data of a three-year study, and the results are subject to errors which may occur due to variability inherent in the year of establishment. This is especially true for conclusions based on seed production. However, first-year data should be valid for such characteristics as flower color and seedling height. The analysis of seed production and seedling height is designed to measure the relative amount of general and specific combining ability of the cones involved. Reciprocals of the single crosses were evaluated for flower color, seedling height, and seed yield to check if reciprocal cross progeny give equal performance.

Evapotranspiration has been defined as the combination of evaporation of water from the soil surface and transpiration of water by vegetation. If the ground is well covered by plants, most of the water is lost by transpiration of water directly from the plant tissue, rather than by evaporation of water directly from the soil surface. The term consumptive use is synonymous with evapotranspiration.

Yield and chemical changes of second-cutting alfalfa hay treated with artificial rain were determined in a 2 x 3 x 2 factorial experiment. Factors were 2 stages of maturity (1 late vegetative; 2 early bloom), 3 levels of artificial rain applied (1 =no rain; 2 =low or approximately 5 mm; 3 =high or approximately 20 mm), and 2 times of applying artificial rain (1 = when drying forage was 40-60% dry matter; 2 =when drying forage was 60-75% dry matter). Thirty samples of alfalfa were collected at the 2 stages of maturity when the alfalfa was fresh cut, pre-sprinkled, pre-baled and prefeeding. Alfalfa samples were analyzed for dry matter, nitrogen, ash, plant cell walls, cellulose, hemicellulose, lignin, total lipids and acid insoluble ash. Available carbohydrates and soluble ash were calculated. Yield of dry matter increased with advancing maturity. Plant cell content fraction was lowered but plant cell wall constituents were increased with advancing stage of growth. Artificial rain significantly affected chemical composition of alfalfa hay. Available carbohydrates, soluble ash and ash decreased due to the effect of leaching. Total lipids was slightly reduced by leaching, while protein content was not changed. Cellulose, lignin and cell wall fractions of alfalfa hay increased consistently under the effect of artificial rain. Sprinkling and processing time did significantly change the chemical composition of alfalfa hay. DM and AlA content increased in relation to process. Interactions among treatment factors were generally nonsignificant. The only significant interactions were maturity-by-artificial rain level effect on available carbohydrate, lipids, cellulose and cell wall. In general, alfalfa hay treated with artificial rain had a lower nutritive and economic value than when it is not affected by any rain.