Crop growth and yield varies among locations due to differences in environmental parameters, such as temperature, relative humidity, solar radiation and vapor pressure deficit. Previous research has shown that increas...Crop growth and yield varies among locations due to differences in environmental parameters, such as temperature, relative humidity, solar radiation and vapor pressure deficit. Previous research has shown that increasing vapor pressure deficit has a negative effect on radiation use efficiency of many crops. In this study, the radiation use efficiency of cot-ton (Gossypium hirsutum L.) grown in two contrasting production environments, Arkansas and California, was evaluated for two years, in 2006 and 2007. Temperature, relative humidity, vapor pressure deficit and photosyntheti-cally active radiation were recorded at both locations. Although the crop in California accumulated more dry matter during the period of the study, the radiation use efficiency was found to be lower compared to Arkansas. Radiation use efficiency for the Arkansas and California locations was estimated at 2.060 and 1.518 g?MJ–1 of intercepted photosynthetically active radiation, respectively. The higher productivity observed in California can be attributed to larger amounts of incident and intercepted radiation in this location. Radiation use efficiency of cotton was estimated to decrease with increasing vapor pressure deficit by a slope of –0.47 g?MJ–1?kPa–1.展开更多
Naturally occurring polyamines in plants have been implicated in floral initiation, and fruit development. The plant growth regulator BM86 was formulated to stimulate seed production and fruit growth by enhancing poly...Naturally occurring polyamines in plants have been implicated in floral initiation, and fruit development. The plant growth regulator BM86 was formulated to stimulate seed production and fruit growth by enhancing polyamine synthe-sis. The objectives of this study were to determine the effect of BM86 on free polyamine content in cotton (Gos-sypium hirsutum L.) ovaries and on seed set efficiency, and also to investigate genotypic differences in ovarian polyamine content. BM86 was applied at the first flower stage and two weeks later at 2.34 mL/ha. This study showed that application of BM86 had a significant positive effect on ovarian polyamine content of cotton. Putrescine and sper-midine one week after the 1st BM86 application and putrescine two week after the 1st BM86 application, were significantly increased compared to the untreated control. Higher seed set efficiency with the BM86 application was observed when the total number of seeds was used for the calculation. However, when the number of harvestable seeds was used to calculate seed set efficiency BM86 had no significant effect. In addition, application of BM86 did not significantly alter seedcotton yield of the crop. Only small differences in ovarian polyamine content were detected among the genotypes tested, possibly due to the narrow genetic pool of the commercial cotton genotypes used. Application of BM86 can significantly increase cotton seed number by enhancing polyamines biosynthesis, but further research is needed to determine how to capitalize on the increased potential number of harvestable seeds.展开更多
文摘Crop growth and yield varies among locations due to differences in environmental parameters, such as temperature, relative humidity, solar radiation and vapor pressure deficit. Previous research has shown that increasing vapor pressure deficit has a negative effect on radiation use efficiency of many crops. In this study, the radiation use efficiency of cot-ton (Gossypium hirsutum L.) grown in two contrasting production environments, Arkansas and California, was evaluated for two years, in 2006 and 2007. Temperature, relative humidity, vapor pressure deficit and photosyntheti-cally active radiation were recorded at both locations. Although the crop in California accumulated more dry matter during the period of the study, the radiation use efficiency was found to be lower compared to Arkansas. Radiation use efficiency for the Arkansas and California locations was estimated at 2.060 and 1.518 g?MJ–1 of intercepted photosynthetically active radiation, respectively. The higher productivity observed in California can be attributed to larger amounts of incident and intercepted radiation in this location. Radiation use efficiency of cotton was estimated to decrease with increasing vapor pressure deficit by a slope of –0.47 g?MJ–1?kPa–1.
文摘Naturally occurring polyamines in plants have been implicated in floral initiation, and fruit development. The plant growth regulator BM86 was formulated to stimulate seed production and fruit growth by enhancing polyamine synthe-sis. The objectives of this study were to determine the effect of BM86 on free polyamine content in cotton (Gos-sypium hirsutum L.) ovaries and on seed set efficiency, and also to investigate genotypic differences in ovarian polyamine content. BM86 was applied at the first flower stage and two weeks later at 2.34 mL/ha. This study showed that application of BM86 had a significant positive effect on ovarian polyamine content of cotton. Putrescine and sper-midine one week after the 1st BM86 application and putrescine two week after the 1st BM86 application, were significantly increased compared to the untreated control. Higher seed set efficiency with the BM86 application was observed when the total number of seeds was used for the calculation. However, when the number of harvestable seeds was used to calculate seed set efficiency BM86 had no significant effect. In addition, application of BM86 did not significantly alter seedcotton yield of the crop. Only small differences in ovarian polyamine content were detected among the genotypes tested, possibly due to the narrow genetic pool of the commercial cotton genotypes used. Application of BM86 can significantly increase cotton seed number by enhancing polyamines biosynthesis, but further research is needed to determine how to capitalize on the increased potential number of harvestable seeds.
