The aim of this study was to elucidate the effects of different machine-harvested cotton-planting patterns on defoliation, yield, and fiber quality in cotton and to provide support for improving the quality of machine-harvested cotton.  In the 2015 and 2016 growing seasons, the Xinluzao 45 (XLZ45) and Xinluzao 62 (XLZ62) cultivars, which are primarily cultivated in northern Xinjiang, were used as study materials.  Conventional wide-narrow row (WNR), wide and ultra-narrow row (UNR), wide-row spacing with high density (HWR), and wide-row spacing with low density (LWR) planting patterns were used to assess the effects of planting patterns on defoliation, yield, and fiber quality.  Compared with WNR, the seed cotton yields were significantly decreased by 2.06–5.48% for UNR and by 2.50–6.99% for LWR, respectively.  The main cause of reduced yield was a reduction in bolls per unit area.  The variation in HWR yield was –1.07–1.07% with reduced bolls per unit area and increased boll weight, thus demonstrating stable production.  In terms of fiber quality indicators, the planting patterns only showed significant effects on the micronaire value, with wide-row spacing patterns showing an increase in the micronaire values.  The defoliation and boll-opening results showed that the number of leaves and dried leaves in HWR was the lowest among the four planting patterns.  Prior to the application of defoliating agent and before machine-harvesting, the numbers of leaves per individual plant in HWR were decreased by 14.45 and 25.00% on average, respectively, compared with WNR, while the number of leaves per unit area was decreased by 27.44 and 36.21% on average, respectively.  The rates of boll-opening and defoliation in HWR were the highest.  Specifically, the boll-opening rate before defoliation and machine-harvesting in HWR was 44.54 and 5.94% higher on average than in WNR, while the defoliation rate prior to machine-harvesting was 3.45% higher on average than in WNR.  The numbers of ineffective defoliated leaves and leaf trash in HWR were the lowest, decreased by 33.40 and 32.43%, respectively, compared with WNR.  In conclusion, the HWR planting pattern is associated with a high and stable yield, does not affect fiber quality, promotes early maturation, and can effectively decrease the amount of leaf trash in machine-picked seed cotton, and thus its use is able to improve the quality of machine-harvested cotton.

Twelve quarters of six lactating cows were inoculated with Mycoplasma leachii strain GN407 through intramammary ductal infusion; another 12 quarters were inoculated with heat-inactivated M. leachii culture medium as negative controls.  Multidisciplinary procedures, including clinical assessment, etiology assessment, pathology and immunohistochemistry (IHC), were used to elucidate the pathogenicity of M. leachii in bovine mastitis.  From post-inoculation days (PIDs) 3 to 9, 12 inoculated quarters developed mild to severe clinical mastitis and mammary tissue histopathological changes, including inflammatory cell infiltration and architectural destruction of mammary gland ducts.  The M. leachii antigen was also detected by IHC in the mammary gland epithelial cells of the inoculated quarters as a weak signal on PID 6 and as a strong signal on PID 9.  The control quarters also developed mild mastitis and histopathological changes on PID 9, and M. leachii was also detected by IHC.  Throughout the experimental period, the quarters of the negative control cow were clinically and pathologically normal, and the M. leachii antigen was not detected.  In conclusion, direct histological and immunohistochemical evidence confirmed that M. leachii causes clinical bovine mastitis through histopathological lesions induced by invasion of the pathogen into mammary gland cells and through inflammatory cell infiltration.

Mycoplasma leachii was initially isolated from arthritic calves in South Queensland, Australia, and its ability to cause clinical polyarthritis in calves was demonstrated by experimental infection.  However, the source of M. leachii infection in calves and its means of spreading are not well known.  In this study, one-month-old calves were inoculated with cultures of M. leachii or joint fluid (collected from M. leachii-infected calves) through the intraarticular, intravenous, intratracheal, intranasal or oral routes.  Multidisciplinary procedures, including clinical assessment, etiology assessment, pathology and immunohistochemistry (IHC), were used to evaluate the pathogenicity of M. leachii in calves and to elucidate the transmission route of M. leachii infection in calves.  The results showed that all calves inoculated intraarticularly with cultured GN407 or joint fluid and two-thirds of the calves inoculated intravenously with joint fluid developed severe polyarthritis, and the M. leachii antigen was detected in the joints of all infected calves by IHC and PCR.  In contrast, calves inoculated with cultured M. leachii or joint fluid through the intratracheal, intranasal or oral routes did not show any M. leachii infection in the clinical assessment, etiology assessment, or pathology and IHC results.  These results indicated that polyarthritis caused by M. leachii in calves is transmitted via the blood route; however, this disease is not transmitted through the respiratory or digestive routes.  In addition, the M. leachii antigen was not detected in the lungs of all the inoculated calves using IHC and PCR, indicating that M. leachii is not associated with pneumonia, even in the calves inoculated through the respiratory duct.  These findings are important information for the prevention and control of calf polyarthritis caused by M. leachii.