Lotus tenuis forage yield has been quantified under defoliation conditions in pastures, grasslands and under dual-purpose production of both livestock forage and seeds. However, little is known about the effects of de...Lotus tenuis forage yield has been quantified under defoliation conditions in pastures, grasslands and under dual-purpose production of both livestock forage and seeds. However, little is known about the effects of defoliation management on L. tenuis flower and pod production and subsequent seed yield. Two field experiments were conducted to study the response of L. tenuis to defoliation at different flowering stages and intensities. In Experiment 1, crops were defoliated at the beginning of the flowering (DBF), mid-flowering (DMF) or full flowering (DFF). In Experiment 2, defoliation was in vegetative stage at low (LDI) or high (HDI) intensities. Defoliation in Experiment 1 neither affected plant cover nor the photosynthetically active radiation intercepted by the crop during pod production. There were less umbels with dehiscent (shattered) pods in the DFF treatment than in Control, DBF and DMF treatments. Flower peak occurred first in the Control, DBF and DMF treatments, and eight days later in DFF plots, however, seed yield was not affected (1324 ± 32.8 kg·ha<sup>-1</sup>). Defoliation intensity did not affect seed yield (962 ± 25.9 kg·ha<sup>-</sup><sup>1</sup>) because of self-compensation which increased harvest index in HDI (14.5% ± 0.6%) compared to the Control and LDI (12.0% ± 0.3%) treatments. Plant survival was not affected by defoliation treatments in any of the experiments. Flowering can be synchronized through defoliation. The blooming of large numbers of flowers in a short time was achieved, reducing the number of shattered pods. Compensatory responses through plant plasticity conferred L. tenuis the ability to overcome defoliation without affecting seed yield. Lotus tenuis defoliation as management tool will be considered in future researches because it is possible to harvest forage and to increase seed yield through a reduction of shattered pods.展开更多
Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is a common grass species in the eastern half of the USA, but legumes grown with it could provide benefits. Obstacles to legume establishment in fescue pastures...Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is a common grass species in the eastern half of the USA, but legumes grown with it could provide benefits. Obstacles to legume establishment in fescue pastures include disease, insect damage, and grass competition. Experiments were performed in 2010 and 2011 at Site 1 to test the efficacy of insect control, disease control, and two methods of grass suppression on seedling establishment of three legumes. The highest seedling density of red clover (Trifolium pretense L.) was obtained with glyphosate treatment regardless of pest control and for clipping without pest control. No overall or consistent benefit was found for white clover (Trifolium pretense L.) or trefoil (Lotus corniculatus L.) from seed and foliar insecticides or fungicides, or for grass suppression by either clipping or glyphosate application. Experiments were performed in 2012 and 2013 at Site 2 to test the efficacy of grass suppression by grazing cattle or by clethodim application. Seedling density of red clover was not significantly improved by either treatment, but the density of birdsfoot trefoil was increased by clethodim, and the density of white clover was increased in 2013 by both methods of grass suppression. Overall, red clover was least sensitive to grass competition. Birdsfoot trefoil was better served by the immediate effect of chemical suppression, whereas white clover benefitted most from the lengthier grass suppression provided by grazing.展开更多
文摘Lotus tenuis forage yield has been quantified under defoliation conditions in pastures, grasslands and under dual-purpose production of both livestock forage and seeds. However, little is known about the effects of defoliation management on L. tenuis flower and pod production and subsequent seed yield. Two field experiments were conducted to study the response of L. tenuis to defoliation at different flowering stages and intensities. In Experiment 1, crops were defoliated at the beginning of the flowering (DBF), mid-flowering (DMF) or full flowering (DFF). In Experiment 2, defoliation was in vegetative stage at low (LDI) or high (HDI) intensities. Defoliation in Experiment 1 neither affected plant cover nor the photosynthetically active radiation intercepted by the crop during pod production. There were less umbels with dehiscent (shattered) pods in the DFF treatment than in Control, DBF and DMF treatments. Flower peak occurred first in the Control, DBF and DMF treatments, and eight days later in DFF plots, however, seed yield was not affected (1324 ± 32.8 kg·ha<sup>-1</sup>). Defoliation intensity did not affect seed yield (962 ± 25.9 kg·ha<sup>-</sup><sup>1</sup>) because of self-compensation which increased harvest index in HDI (14.5% ± 0.6%) compared to the Control and LDI (12.0% ± 0.3%) treatments. Plant survival was not affected by defoliation treatments in any of the experiments. Flowering can be synchronized through defoliation. The blooming of large numbers of flowers in a short time was achieved, reducing the number of shattered pods. Compensatory responses through plant plasticity conferred L. tenuis the ability to overcome defoliation without affecting seed yield. Lotus tenuis defoliation as management tool will be considered in future researches because it is possible to harvest forage and to increase seed yield through a reduction of shattered pods.
文摘Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is a common grass species in the eastern half of the USA, but legumes grown with it could provide benefits. Obstacles to legume establishment in fescue pastures include disease, insect damage, and grass competition. Experiments were performed in 2010 and 2011 at Site 1 to test the efficacy of insect control, disease control, and two methods of grass suppression on seedling establishment of three legumes. The highest seedling density of red clover (Trifolium pretense L.) was obtained with glyphosate treatment regardless of pest control and for clipping without pest control. No overall or consistent benefit was found for white clover (Trifolium pretense L.) or trefoil (Lotus corniculatus L.) from seed and foliar insecticides or fungicides, or for grass suppression by either clipping or glyphosate application. Experiments were performed in 2012 and 2013 at Site 2 to test the efficacy of grass suppression by grazing cattle or by clethodim application. Seedling density of red clover was not significantly improved by either treatment, but the density of birdsfoot trefoil was increased by clethodim, and the density of white clover was increased in 2013 by both methods of grass suppression. Overall, red clover was least sensitive to grass competition. Birdsfoot trefoil was better served by the immediate effect of chemical suppression, whereas white clover benefitted most from the lengthier grass suppression provided by grazing.
