Studies have not been conducted examining the influence of the spatial distribution of LiDAR-derived tree measuresments and their affects the predictive ability of LiDAR-derived forest metrics as input for growth-and-yield analysis on individual trees. This study addresses both of these voids in current knowledge and determines the suitability, concerns and application of LiDAR for time-series analysis, specifically forest growth-and-yield. LiDAR datasets of the same site acquired in 1999, 2000, 2002, and 2006 by different vendors using different specifications were utilized in this study. Directional differences of Lidar-identified tree top locations were examined. Minimal location differences were noted, but no bias occurred. Differences in locations appeared to be from environmental effects such as wind. Improvements on individual-tree identification using a time-series analysis approach were implemented. The treeinding model was improved with a Boolean decision rule yielding significant differences in stand density calculations in 1.4 m spacing plots and for overall calculations of the 2000 and 2002 LiDAR datasets. Individual tree measurements derived from the 1999 LiDAR data were used to estimate growth to the 2006 data. These growth-and-yield values were compared with field-derived and field-measured values. Significant differences were found between the LiDAR- and field-derived measures of growth-and-yield. These increased over time and were believe to be compounded error from the LiDAR-estimated tree diameters. LiDAR datasets can be correlated to previous LiDAR datasets of the same area with very little effort. LiDAR tree identification can be improved using decision criteria based on subsequent LiDAR datasets of the same area. The ability to track individual trees by location over time using LiDAR could yield large datasets to potentially improve growth-and-yield modeling efforts and other stand characterization procedures.

[Abstract]: Yield maps provide essential information for the spatial analysis and evaluation of crop production management at a within field level. Technology has been developed to conduct yield mapping in various crops including grain, potatoes and forage, but as yet no technology exists for yield mapping sugar cane. The chopper harvester is the most common form ofmechanical harvester for sugar cane. Therefore, the goal of this research is to develop a yield mapping system for the chopper type sugar cane harvester.After a review, it is proposed that a suitable accuracy goal for the sugar cane mass flow sensor would be ‘less than 5% cumulative measurement error, 95% of the time (2 standard deviations), measured over a 100m2 harvest area’.Existing mass flow sensors for other crops are reviewed.Based on this review four potential techniques are proposed to measure the mass flow rate of sugar cane. These were defined as the chopper power, elevator power and feed roller separation and weigh pad. These weretested simultaneously by placing various sensors on a single harvester and comparing the sensor outputs with the mass flow rate as measured by a weigh truck. In this trial, all techniques offered potential but none produced results close to the accuracy goal. A weighing technique, known as the ‘weigh pad’, offered the most potential for improvement and potential to accurately measure the mass flow rate with a single calibration under all conditions. The weigh pad technique suffered from very small load cell sensitivity to flow rate, drift in baseline readings and susceptibility to mechanical noise/acceleration dynamics.An opportunity arose to install a complete yield mapping system on a harvester within a commercial operation. This opportunity was accepted to assess the potential for applying yield maps to the agronomic management of sugar cane. Because the weigh pad sensor required further development at this stage, chopper and elevator power were used as a measure of mass flow rate. A full yield mapping system was developed. Yield mapping, directed soil sampling and variable rate gypsum application was conducted on a case study field. Economic analysis shows a clear economic benefit when compared with standardmanagement.Analysis is conducted on the weigh pad sensor examining its susceptibility to mechanical noise/acceleration dynamics. Theory is developed to mathematically model the effects of acceleration dynamics on the accuracy of weigh pad sensor. Laboratory bench testing supported the mathematical model. From the theoretical and experimental analysis a number of conclusions are drawn:· The weigh pad should be made as light as possible to minimise the error due todynamic conditions.· Electronic analogue filters should be used to reduce the noise due to externalacceleration.· The weigh pad should be as rigid as possible to maximise its natural frequency.A new weigh pad sensor was designed based on these conclusions. Field trials indicated the effects of external accelerations dynamics were significantly reduced. Baseline drift was then found as the next major factor limiting accuracy. The baseline drift was principally caused by the secondary extractor fan of the harvester inducing a negative pressure on the weighpad. A rubber curtain placed between the weigh pad and the secondary extractor fan reduced the negative force on the weigh pad due to the secondary extractor fan by 74% (from 17 N to 4.4 N). Therefore it is recommended the curtain be used to minimise the impact of the secondary extractor fan on the baseline drift of the weigh pad.A yield mapping system has been developed for the sugar cane chopper harvester incorporating the weigh pad sensor, a ground speed sensor, a DGPS receiver, a yielddisplay/monitor and data logger. Three identical systems have been constructed and installed on three harvesters for the 1998 cane harvest season. The results show sugar cane could be yield mapped using standard yield mapping principles.The level of accuracy being achieved by the yield mapping system is less than 16% error, with 95% confidence, over a measurement area of approximately 1400 m2. Although theaccuracy achieved is not to the desired research goal, yield maps were produced with satisfactory detail to make agronomic management decisions. The reliability of the sugar cane yield mapping system under field condition in a commercial operation was satisfactory. However, two techniques are proposed (“auto-zeroing” and “batch weighing” techniques) to improve the accuracy and reliability of the weigh pad readings during wet or adverseharvesting conditions.After note: At the time of writing the NCEA along with Case Austoft (CNH) were continuing to conduct research and development on the system and are intending to make theyield mapping system available as a standard item on new harvesters and a retrofit unit on existing harvesters in the near future (C. Barret, per. comm. 2001). The proposed “autozeroing” and “batch weighing” techniques are being tested.

Forage kochia (Bassia prostrata, [L.] A. J. Scott) (Synonym = Kochia prostrata [L.] Schrad.) is a perennial semi-shrub that is valued for its forage quality and ability to restore degraded rangeland. However, establishment success of forage kochia plantings in western North America has been erratic. These failures leave the land vulnerable to erosion and invasion of undesirable plants. This research focused on the germination dynamics of forage kochia accessions as it relates to harvest date, planting date, age of seed, and environmental conditions. The effect of planting date, age of seed, and environmental conditions on forage kochia germination was elucidated by planting recently harvested (2010) and year-old, cold-stored seed (2009) monthly, during a four-month period at two locations. Two entries were tested, Immigrant, the standard subspecies virescens cultivar, and an experimental line, Sahsel, of subspecies grisea. Regardless of planting date, location, or age of seed, Sahsel exhibited higher germination percentages than Immigrant. The age of the seed lots used also significantly affected (P<0.05) the germination percentage. Field germination averaged over location and planting date of year-old Immigrant seed was 89.5% less than the current-year fresh seed, and similarly year-old Sahsel seed had 83.6% less germination than current-year seed. Although the two locations were subjected to very different weather patterns, the germination percentage of seeds at each location was not significantly different (P=0.3156). In the year we conducted our study (2011), the germination percentage from planting in February was significantly higher (P<0.05) than January, which was significantly higher (P<0.05) than both March and April. In the final set of trials, different harvest dates were tested by collecting seed in October, November, and December from seven forage kochia accessions. Measurements for total seed yield, 100-seed weight, and germination were collected from seed harvested each month. The month of harvest, accession, and month × accession interaction were significant (P<0.05) for each measurement in the study. Two accessions, Pustsel and KZ6Xsel, matured the earliest and had peak seed production at the October harvest (15.1 and 13.4 g plant-1, respectively). The remaining accessions had maximum yield and viable seed from the November harvest.

The aim of this study was to evaluate of selected factors on milking yeild and longevity of Czech Fleckvieh cattle. There were monitored the indicators of the amount of milk for the first lactation in kg, the lifetime performance in kg, the age at the first calving, the functional longevity in days, the lenght of the service period, the lenght of the meantime days, the live weight in kg, the elimination of the causes from the breed. 273 culled cows were included. The relationship between some of the observed factors were signifiant such as the amount of milk yeild on the first lactation and the lifetime performance. In the opposite, there was no signifiant relationship between the age at the first calving and the functional longevity. The milk performance at first calving has been increasing with the age.

The set includes 1782 heads of culling Czech fleckvieh cattle eliminated from 1 January 2012 to 1 September 2015. Influences on the first calving age, calving interval and lifetime milk yield were detected for data in the set. The following items were integrated among selected lifetime milk yield influences : genotype, herd, first calving age and first calving month. It was also tested whether the age of the first calving of milking cows is influenced by genotype and a herd. The last tested hypothesis was related to the influence of genotype and a herd on the length of the carving interval. The influence of genotype, lactation and the age of first calving cows on the way of elimination was investigated in the set as well. Multi-factor analysis of variance were used for the calculation of differences among the individual tested groups . With respect to statistical significance there was a statistically significant effect (p <0.05)of the herd and genotype on the age of the first calving cows found out. From the set it is evident that cows calved earlier reached better lifetime milk yield than cows calved at the older age (p <0.05). Another statistically significant difference (p <0.05) was found out within the first month of calving. Milking cows calved during colder periods of the year reached the higher lifetime milk yield. The influence of genotype on milk yield was not proved in this set. This also holds to reproductive parametres, there was no influence of genotype and the age of first calving on calving interval. When observing the outcome in terms of how we can positively evaluate the elimination of voluntarily culled milking cows, which is 34% .This situation is significantly lower than it is stated in literature and shows a good zootechnical care of the herds. In terms of elimination method there were the most dairy cows culled because of fertility - 31%. This fact shows that fertility is one of the main factors influencing the managament and profitability of dairy herds of cattle.