No description available.

Using data from temporary and permanent sample plots various functions describing different stand parameter relationships were developed for P. patula growing at Sao Hill, Southern Tanzania. The functions include equations for: a Weibull diameter distribution, a single tree diameter increment, stand basal area, mortality, and height/diameter relationship. Also site index curves based on a Chapman-Richards equation were constructed, and a compatible taper/volume estimation system was developed. The functions were integrated into a micro-computer model SIMUL in BASIC language. The model is capable of estimating saw-log and pulp-log volumes for different spacings and thinning regimes. Inputs to the model are: initial and simulation ages, stocking/ha, stand mean and standard deviation of diameter at breast height (dbh), basal area/ha, site, dominant height, and minimum diameters and lengths of saw-logs and pulplogs. The output gives yearly values/ha for; stocking, total volume, total basal area/ha, means for dbh, height and tree volume, mortality number and volume/ha, and volumes of saw-logs and pulplogs as out-turn from subsequent thinnings and the final clearfelling. Validation with independent data showed that the model works satisfactorily. Experimental runs at different levels of spacing and thinning regimes suggested that the current thinning schedule at Sao Hill is too heavy and results in loss in total volume. The highest utilizable volumes (mainly saw logs) may be obtained by using the current spacing of 2.7 x 2.7m followed by one thinning at the age of about 11 years to leave about 1100 stems/ha, with a rotation age of 25 years. This treatment is also justified economically giving the highest present value at an interest rate of 3%. The current rotation age 15 years (unthinned) for the production of pulp wood only is ideal to produce the required dimensions (10-20 cm diameter) of pulp logs. SIMUL is recommended for use at Sao Hill and the technique may be adopted for other plantation species in Tanzania with new parameter estimates for the equations.

Master of Arts / Department of Economics / Lloyd B. Thomas / A negative-sloped Treasury curve is often cited in financial news articles and by Federal Reserve economists as a predictor of recessions. This report reviews previously published research examining the reliability of yield curves predicting recessions. Findings show that the yield curve inverts two or more quarters before recessions, with short-term interest rates rising above long-term interest rates. Probit regression has proven a reliable method for generating estimated probabilities of future recessions that, in turn, are useful for both monetary policy and asset allocation decision-making.

In this work the effects of mother plant nutrition and flower position on the plant in relation to different harvest stages on French beans (Phaseolus vulgaris L. cv. Cascade); seed yield, quality and progeny performance have been studied. In three pot experiments under glass and one in the field, different levels of nitrogen, phosphorus, potassium and molybdenum were applied to the mother plant and it was found that higher seed yields were obtained with the higher nutrient levels tested, but these high seed yields were not necessarily accompanied by high quality. Seed yield and quality increased with the increase of nitrogen and potassium. The phosphorus effect however, was different, in that the seed yield increased in relation to the levels but the seed quality decreased. Molybdenum was found to be necessary in moderate amounts, especially for the seed quality. The interactions between nitrogen and phosphorus levels (NP) and between nitrogen, phosphorus and potassium (NPK) were found to be very important for bean seed quality, because their significant effect was similar and constantly present in most of the seed vigour components examined. It seems that the combinations of high nitrogen levels with moderate amounts of phosphorus applied to the mother plant resulted in seed of good quality. In one pot experiment under glass the progeny performance was examined, using seed from the 1st mother plant nutrition experiment and it was found that the mother plant nutrition affected the progeny in it's early stages. This effect disappeared later and no difference in progeny seed yield was found. In two pot experiments under glass the bean pods were harvested at different stages and the pods from the main axis were separated from the pods on the secondary branches grown mainly from the axils of the primary leaves. It was found that the quality of seed from the secondary branches was lower than the quality of seed from the main axis. However, this difference in seed quality became less with the later harvests. The following tests were used to assess seed quality: the official germination test, seedling evaluation test, cold test, and electrical conductivity test. In addition, the seed size was determined and the seeds were analysed for total nitrogen, phosphorus and potassium content.

Field and greenhouse studies were conducted to assess the effects of row-spacing on diseases, weed control, herbicide persistence and plant development in peanut. Tebuconazole, when averaged across cultivars and row spacing, effectively controlled white mold (57%) and rust (58%). Azoxystrobin also controlled white mold (58%) and controlling rust (44%). Both fungicides reduced leaf spot severity in the conventional and twin rows when compared to untreated plots. Twin rows showed a 10% yield increase compared to the conventional planting. Both diclosulam and imazapic, when applied to twin rows at the full and reduced rate, provided better yellow nutsedge control than when applied to the conventional row. Twin rows yielded higher than the conventional rows when averaged across herbicides in one year. All full rate herbicide treatments enhanced yield over the untreated check. Diclosulam and imazapic treated soil sampled 60 DAP adversely affected all four crops. The advantage of planting peanuts in twin rows to reduce diclosulam and imazapic residual concentrations was not apparent. Georgia Green and Tamrun 96 planted in twin rows at three of the four locations in 1999 and 2000 yielded higher than peanuts planted in conventional rows. Yields were comparable to twin-row spacings that had higher plant densities. Georgia Green and Tamrun 96 planted in conventional rows, in most cases, had higher yields than narrow-rows. Measurements for plant diameter, pod distribution, and main stem length were higher with Tamrun 96 at most row spacings and planting densities compared to the respective Georgia Green planting densities and row spacings. Both cultivars when planted in twin or narrow rows at all planting densities did not enhance maturity when sampled late season. Georgia Green and Tamrun 96 when planted in conventional rows had the most pods/plant compared to the narrow and twin row spacing. No clear evidence was found to suggest that peanuts grown in narrow or twin rows increased white mold disease incidence. Grades for Georgia Green were higher than Tamrun 96 when planted in twin rows at the standard planting density. Tamrun 96 in twin rows at the standard planting density had a higher grade than when planted in conventional rows at the low planting density.

Aflatoxins are potent carcinogens produced by the fungus Aspergillus flavus Link:Fr and are a significant preharvest problem in maize production in Texas, the southern US, and subtropical climates. Several sources of maize germplasm are available which reduce preharvest aflatoxin accumulation, but many of these sources lack agronomic performance for direct use as a parent in commercial hybrids. Tropical germplasm is a source of both resistance to aflatoxin accumulation resistance and agronomic performance traits. The goal of this study was to investigate germplasm for traits to reduce preharvest aflatoxin accumulation. The specific objectives of this research were: 1) to validate QTL estimates previously identified in lines per se and estimate new QTL associated with reduced aflatoxin accumulations and agronomic traits; 2) to evaluate agronomic characteristics of selections from a RIL population in testcrosses at multiple locations across Texas; and (3) to release agronomically desirable germplasm sources with reduced risk to preharvest aflatoxin accumulation. A total of 96 QTLs were detected across fourteen measured traits using an RIL population of 130 individuals in testcross hybrids evaluated in five environments. Three QTL detected in per se analyses were also detected in hybrid testcrosses. Previously unreported QTL were detected on chromosomes 3, 4, 8 and 9. Within each of the two years, neither subset of the RIL testcross hybrids produced grain yields equal to commercial hybrid checks in these trials, but one testcross in 2008 produced grain yield within 10 percent of commercial check hybrids and in 2009, five RIL testcrosses produced grain yield within 17 percent of the commercial check hybrids. Although RIL testcrosses did not yield more than the commercial checks, they will be a source of germplasm for reduced aflatoxin. Improved sources of maize germplasm lines Tx736, Tx739, and Tx740 have been selected for adaptation to southern US and Texas growing environments with traits that reduce aflatoxin accumulation. Each of the lines in testcross accumulated significantly fewer aflatoxins than commercial hybrids in the trial.

Baby corn (Zea mays L.) consists of unfertilized young ears harvested at silkemergence. The 2011 study was a culmination of four successive years of productionand evaluation of baby corn at Western Kentucky University (36.93 N, 86.47 W). Theobjective was to compare the effect of tassel removal on baby corn (BC) production onfour cultivars of corn, two field (‘N77P-3000GT’, ‘N68B-3000GT’) and two sweet(‘Silver Queen’, ‘Peaches N Cream’). Results indicated that tassel removal gavesignificant increases (P<0.01) of BC ears across harvests (H) and cultivars; however, the effect was not consistent over treatments. For harvests, the difference due to detasseling was significant (P<0.05) for H2 and H3, but not significant (P>0.05) for H1 or H4. For cultivars, numerical values were higher for detasseled than non-detasseled treatments in the first three harvests for each cultivar, but significant (P<0.05) only for ‘Peaches n’ Cream’. Quality of BC from both tassel treatments decreased in H3 and H4. Based upon the increased number of ears resulting from detasseling, additional labor costs would be more than covered. Baby corn has excellent potential as a niche crop for producers and consumers in Central Kentucky.

No description available.

This study was conducted to assess cutout and value differences in Yield Grade 4 beef carcasses by evaluating impacts of gender, fatness, muscling, and weight. USDA Choice, Yield Grade 4 carcasses (n = 60) were selected according to gender: heifers (n = 20) and steers (n = 40), and weight groups: lightweight heifers (315.5 - 362.9 kg) and steers (362.9 - 408.2 kg), and heavy weight heifers (362.9 - 408.2 kg) steers (408.2 - 453.6 kg). Within weight classes, carcasses were separated according to ribeye area per 45.36 kg of HCW ratio (REAcm2 :100 kg): heifers (>21.76) and (< or equal to 21.76); steers (greater than 20.07) and (less than or equal to 20.07) based on analysis from NBQA-2005 (National Beef Quality Audit - 2005). Data in this study showed that within yield grade 4 carcasses, there are both conformational and value differences associated with different types of yield grade 4's, particularly when sex-class is considered due to the biological differences associated with fat and muscle deposition between genders. As expected, carcasses from heifers had more trimmable fat than steers, and steers had higher yields of certain cuts from the chuck and in bone differences than did heifers. In this demonstration, applied estimated discounts out-weighted the value differences found in cutout values. There were no clear associations in carcass traits that could be used to more accurately sort value differences in Yield Grade 4 carcasses with exception to sex-class. However, the present data suggests a need to establish a prediction equation that predicts carcass value in addition to the current Yield Grade equation. In conclusion, further research is needed incorporating all yield grade carcass types. Standard carcass fabrication styles and fat trim levels consistent with industry are needed to further assign current subprimal and minor cut prices. Additional premium and discount prices are needed for a current industry representation to obtain if premiums and discounts are being applied according to potential profits or losses incurred because of cutability differences found between the different yield grades.

Field and greenhouse studies were conducted to assess the effects of row-spacing on diseases, weed control, herbicide persistence and plant development in peanut. Tebuconazole, when averaged across cultivars and row spacing, effectively controlled white mold (57%) and rust (58%). Azoxystrobin also controlled white mold (58%) and controlling rust (44%). Both fungicides reduced leaf spot severity in the conventional and twin rows when compared to untreated plots. Twin rows showed a 10% yield increase compared to the conventional planting. Both diclosulam and imazapic, when applied to twin rows at the full and reduced rate, provided better yellow nutsedge control than when applied to the conventional row. Twin rows yielded higher than the conventional rows when averaged across herbicides in one year. All full rate herbicide treatments enhanced yield over the untreated check. Diclosulam and imazapic treated soil sampled 60 DAP adversely affected all four crops. The advantage of planting peanuts in twin rows to reduce diclosulam and imazapic residual concentrations was not apparent. Georgia Green and Tamrun 96 planted in twin rows at three of the four locations in 1999 and 2000 yielded higher than peanuts planted in conventional rows. Yields were comparable to twin-row spacings that had higher plant densities. Georgia Green and Tamrun 96 planted in conventional rows, in most cases, had higher yields than narrow-rows. Measurements for plant diameter, pod distribution, and main stem length were higher with Tamrun 96 at most row spacings and planting densities compared to the respective Georgia Green planting densities and row spacings. Both cultivars when planted in twin or narrow rows at all planting densities did not enhance maturity when sampled late season. Georgia Green and Tamrun 96 when planted in conventional rows had the most pods/plant compared to the narrow and twin row spacing. No clear evidence was found to suggest that peanuts grown in narrow or twin rows increased white mold disease incidence. Grades for Georgia Green were higher than Tamrun 96 when planted in twin rows at the standard planting density. Tamrun 96 in twin rows at the standard planting density had a higher grade than when planted in conventional rows at the low planting density.