A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice.The main objective of this study was to evaluate the impact of harvester head...A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice.The main objective of this study was to evaluate the impact of harvester header,harvester type,and weather conditions on field loss and milling quality of rough rice.Four popular harvesters equipped with different headers:John Deere 9870 with header D60-S,John Deere 9860 with header D972-S,Hardy,and John Deere 9770 with stripper header were evaluated in this study.The header and total field losses of rice were evaluated for each harvester under regular,rainy and windy weather conditions.Tests were conducted in a rice field cultivated with medium grain rice,variety M206,at Grimes,CA.Total rice yield(TRY),head rice yield(HRY)and whiteness index(WI)were examined to evaluate the effect of weather conditions on milling quality.The obtained results revealed that the rice field loss was affected by harvester header and type,and weather conditions.Among the conventional headers,D60-S significantly reduced the rice loss compared to the D972-S and the Hardy.Harvesting with John Deere 9860 resulted in significant header and field loss compared to other tested harvesters.The average loss increased from 236.2 kg/hm^(2)and 445.2 kg/hm^(2)under regular condition to 711.1 kg/hm^(2)and 907.9 kg/hm^(2)under windy condition for John Deere 9870 and John Deere 9860,respectively.The corresponding loss percentages increased from 2.6%and 4.9%to 7.9%and 10.1%.HRY was significantly affected by weather condition at harvest time.However,the weather condition had no significant effect on TRY and WI.To minimize the rice field loss and obtain good milling quality,commercial rice harvesting during regular weather conditions is important.A proper combination of harvester type and header could be vital for reducing the rice loss.展开更多
This research was conducted to develop an effective approach to sort off-ground harvested almonds for efficient drying based on their physical and aerodynamic properties.Three popular varieties were studied,including ...This research was conducted to develop an effective approach to sort off-ground harvested almonds for efficient drying based on their physical and aerodynamic properties.Three popular varieties were studied,including Nonpareil,Monterey,and Fritz.The insect damage,axial dimensions,weight ratio,moisture content,bulk density and terminal velocity of in-hull almonds,in-shell almonds and loose hull at harvest were measured.The results indicated that the insect infestation percentage in the off-ground harvested almonds ranged from 2.5%to 6.3%,which was about half of those in the conventional on-ground dried almonds.Loose hulls and in-hull almonds had higher moisture content and wider moisture distribution than those of in-shell almonds,suggesting that sorting of the almonds and drying them separately are necessary for efficient handling and processing.Thickness was the smallest axial dimension of an almond,and thus could be used for sorting.The cut-off sizes of 16.5 mm,21.3 mm and 21.1 mm could separate 100%of the in-shell almonds from the rest for Nonpareil,Monterey and Fritz varieties,respectively,as the first step.In the second step,applying terminal velocities of 12.3 m/s,11.8 m/s and 12.2 m/s could efficiently separate the in-hull almonds and loose hulls for Nonpareil,Monterey and Fritz varieties,respectively.Overall,up to 76.7%of the loose hulls could be removed,and up to 3.3%in-hull almonds may be lost during the sorting process.The experimental results provided important information for developing efficient sorting and drying methods with improved throughput,energy efficiency,better quality and safety of off-ground harvested almonds.展开更多
文摘A better understanding of factors affecting field losses and milling quality during harvest is needed to improve the economic value of rice.The main objective of this study was to evaluate the impact of harvester header,harvester type,and weather conditions on field loss and milling quality of rough rice.Four popular harvesters equipped with different headers:John Deere 9870 with header D60-S,John Deere 9860 with header D972-S,Hardy,and John Deere 9770 with stripper header were evaluated in this study.The header and total field losses of rice were evaluated for each harvester under regular,rainy and windy weather conditions.Tests were conducted in a rice field cultivated with medium grain rice,variety M206,at Grimes,CA.Total rice yield(TRY),head rice yield(HRY)and whiteness index(WI)were examined to evaluate the effect of weather conditions on milling quality.The obtained results revealed that the rice field loss was affected by harvester header and type,and weather conditions.Among the conventional headers,D60-S significantly reduced the rice loss compared to the D972-S and the Hardy.Harvesting with John Deere 9860 resulted in significant header and field loss compared to other tested harvesters.The average loss increased from 236.2 kg/hm^(2)and 445.2 kg/hm^(2)under regular condition to 711.1 kg/hm^(2)and 907.9 kg/hm^(2)under windy condition for John Deere 9870 and John Deere 9860,respectively.The corresponding loss percentages increased from 2.6%and 4.9%to 7.9%and 10.1%.HRY was significantly affected by weather condition at harvest time.However,the weather condition had no significant effect on TRY and WI.To minimize the rice field loss and obtain good milling quality,commercial rice harvesting during regular weather conditions is important.A proper combination of harvester type and header could be vital for reducing the rice loss.
文摘This research was conducted to develop an effective approach to sort off-ground harvested almonds for efficient drying based on their physical and aerodynamic properties.Three popular varieties were studied,including Nonpareil,Monterey,and Fritz.The insect damage,axial dimensions,weight ratio,moisture content,bulk density and terminal velocity of in-hull almonds,in-shell almonds and loose hull at harvest were measured.The results indicated that the insect infestation percentage in the off-ground harvested almonds ranged from 2.5%to 6.3%,which was about half of those in the conventional on-ground dried almonds.Loose hulls and in-hull almonds had higher moisture content and wider moisture distribution than those of in-shell almonds,suggesting that sorting of the almonds and drying them separately are necessary for efficient handling and processing.Thickness was the smallest axial dimension of an almond,and thus could be used for sorting.The cut-off sizes of 16.5 mm,21.3 mm and 21.1 mm could separate 100%of the in-shell almonds from the rest for Nonpareil,Monterey and Fritz varieties,respectively,as the first step.In the second step,applying terminal velocities of 12.3 m/s,11.8 m/s and 12.2 m/s could efficiently separate the in-hull almonds and loose hulls for Nonpareil,Monterey and Fritz varieties,respectively.Overall,up to 76.7%of the loose hulls could be removed,and up to 3.3%in-hull almonds may be lost during the sorting process.The experimental results provided important information for developing efficient sorting and drying methods with improved throughput,energy efficiency,better quality and safety of off-ground harvested almonds.
