The experiment aimed to evaluate the effects of N and trinexapac-ethyl （TE） to the growth of Kentucky bluegrass. By using the method of randomized blocks design, 4 N levels, 0 （N1）, 20 （N2）, 25 （N3）, and 30 ...The experiment aimed to evaluate the effects of N and trinexapac-ethyl （TE） to the growth of Kentucky bluegrass. By using the method of randomized blocks design, 4 N levels, 0 （N1）, 20 （N2）, 25 （N3）, and 30 （N4） kg N ha t mon% with TE at 0 （T1）, 312.5 （T2） and 625 （T3） mL ha-1 every 10 d effect on the total height, clippings and chlorophyll concentration of Kentucky bluegrass were evaluated. Results showed that total height and total clippings of Kentucky bluegrass were reduced by treating with TE and increased by treating with N. Kentucky bluegrass treated with 312.5 and 625 mL ha ＇ per 10 d had total clippings and total height reduced 30 and 45% under different N application level. The N × TE interaction was significant for the chlorophyll concentration of Kentucky bluegrass. The chlorophyll concentration of Kentucky bluegrass treated with TE at 625 mL ha-1 every 10 d was significantly higher than that of Kentucky bluegrass treated with 312.5 mL ha-1 every 10 d at the same N level. The chlorophyll concentration of turfgrass treated with TE at 625 mL ha-1 every 10 d receiving 30 kg N ha -1 month-1 was the highest. Based on the index of turf growth and the chlorophyll concentration, turfgrass receiving 20 or 30 kg N ha-1 month-1 with 625 mL TE ha i every 10 d could balance the problem of mowing frequency and growth quickly while keeping a good quality.展开更多
The simulation of oat grain productivity does not contemplate the use of efficient models that involve important management with meteorological elements. The objective of the study is to propose a mathematical model c...The simulation of oat grain productivity does not contemplate the use of efficient models that involve important management with meteorological elements. The objective of the study is to propose a mathematical model capable of simulating the oat grain productivity through the management of nitrogen and growth regulator with variables related to the plant and to meteorological elements. In this study, two experiments were conducted in the years of 2013, 2014 and 2015: one to quantify biomass productivity and another to determine grain productivity and lodging at the management doses of nitrogen and growth regulator. The experimental design was a randomized block with four replications in a 4 × 3 factorial scheme for 0, 200, 400 and 600 mL·ha-1 growth regulator doses and 30, 90 and 150 kg·ha-1 nitrogen doses, respectively. During the crop cycles, the meteorological variables thermal sum, radiation and rainfall were quantified. The mathematical model proposed, which combines polynomial regression of the harvest index with multiple linear regression of the biological productivity, is efficient in the simulation of oat grains productivity with the use of growth regulator, nitrogen and meteorological elements. Thus, it adds to the conventional models of simulation and becomes an aid tool for making decisions regarding the management of oats culture.展开更多
The objective of this work is to verify the influence of the plant regulator trinexapac-ethyl on plant growth and physiological quality of upland rice seeds. We used an upland rice genotype, and the growth regulator w...The objective of this work is to verify the influence of the plant regulator trinexapac-ethyl on plant growth and physiological quality of upland rice seeds. We used an upland rice genotype, and the growth regulator was the trinexapac-ethyl. The experiment was completely randomized in a 4 × 8 factorial design related to four concentrations of the plant regulator trinexapac-ethyl [0 (without growth regulator), 0.25, 0.50, and 0.75 L c.p. ha-1] and 7 plant collection times [14, 28, 42, 56, 70, 84, 98 days after emergence (DAE)], with four replicates. To determine growth attributes, we evaluated total dry matter, dry matter production rate, relative growth rate, leaf area ratio, leaf matter, leaf area index, solar energy conversion efficiency and partition of assimilates. The physiological quality of the seeds was evaluated based on germination, first germination count, field emergence, emergence speed index and seedling dry matter. Plant growth was affected by the growth regulator. Total dry matter, dry matter production rate and solar energy conversion efficiency decreased, while leaf area index, leaf area ratio and leaf matter increased due to the effects of the growth regulator. The dry matter partition of plants changed in plants subjected to the growth regulator, with a delay in the targeting of assimilates to reproductive organs and a greater allocation to roots at the end of the cycle in plants subjected to the doses 0.50 and 0.75 L·ha-1 of growth regulator. Seed vigor was adversely affected by the growth regulator.展开更多
基金supported by the Key International Science and Technology Cooperation Program of China(2006DFA33630)
文摘The experiment aimed to evaluate the effects of N and trinexapac-ethyl （TE） to the growth of Kentucky bluegrass. By using the method of randomized blocks design, 4 N levels, 0 （N1）, 20 （N2）, 25 （N3）, and 30 （N4） kg N ha t mon% with TE at 0 （T1）, 312.5 （T2） and 625 （T3） mL ha-1 every 10 d effect on the total height, clippings and chlorophyll concentration of Kentucky bluegrass were evaluated. Results showed that total height and total clippings of Kentucky bluegrass were reduced by treating with TE and increased by treating with N. Kentucky bluegrass treated with 312.5 and 625 mL ha ＇ per 10 d had total clippings and total height reduced 30 and 45% under different N application level. The N × TE interaction was significant for the chlorophyll concentration of Kentucky bluegrass. The chlorophyll concentration of Kentucky bluegrass treated with TE at 625 mL ha-1 every 10 d was significantly higher than that of Kentucky bluegrass treated with 312.5 mL ha-1 every 10 d at the same N level. The chlorophyll concentration of turfgrass treated with TE at 625 mL ha-1 every 10 d receiving 30 kg N ha -1 month-1 was the highest. Based on the index of turf growth and the chlorophyll concentration, turfgrass receiving 20 or 30 kg N ha-1 month-1 with 625 mL TE ha i every 10 d could balance the problem of mowing frequency and growth quickly while keeping a good quality.
文摘The simulation of oat grain productivity does not contemplate the use of efficient models that involve important management with meteorological elements. The objective of the study is to propose a mathematical model capable of simulating the oat grain productivity through the management of nitrogen and growth regulator with variables related to the plant and to meteorological elements. In this study, two experiments were conducted in the years of 2013, 2014 and 2015: one to quantify biomass productivity and another to determine grain productivity and lodging at the management doses of nitrogen and growth regulator. The experimental design was a randomized block with four replications in a 4 × 3 factorial scheme for 0, 200, 400 and 600 mL·ha-1 growth regulator doses and 30, 90 and 150 kg·ha-1 nitrogen doses, respectively. During the crop cycles, the meteorological variables thermal sum, radiation and rainfall were quantified. The mathematical model proposed, which combines polynomial regression of the harvest index with multiple linear regression of the biological productivity, is efficient in the simulation of oat grains productivity with the use of growth regulator, nitrogen and meteorological elements. Thus, it adds to the conventional models of simulation and becomes an aid tool for making decisions regarding the management of oats culture.
基金the support of CNPq,National Council for Scientific and Technological Development,Brazilthe scholarship granted of National Council for Scientific and Technological Developmentthe National Council for Scientific and Technological Development(CNPq)for the concession of research productivity grant(PQ2).
文摘The objective of this work is to verify the influence of the plant regulator trinexapac-ethyl on plant growth and physiological quality of upland rice seeds. We used an upland rice genotype, and the growth regulator was the trinexapac-ethyl. The experiment was completely randomized in a 4 × 8 factorial design related to four concentrations of the plant regulator trinexapac-ethyl [0 (without growth regulator), 0.25, 0.50, and 0.75 L c.p. ha-1] and 7 plant collection times [14, 28, 42, 56, 70, 84, 98 days after emergence (DAE)], with four replicates. To determine growth attributes, we evaluated total dry matter, dry matter production rate, relative growth rate, leaf area ratio, leaf matter, leaf area index, solar energy conversion efficiency and partition of assimilates. The physiological quality of the seeds was evaluated based on germination, first germination count, field emergence, emergence speed index and seedling dry matter. Plant growth was affected by the growth regulator. Total dry matter, dry matter production rate and solar energy conversion efficiency decreased, while leaf area index, leaf area ratio and leaf matter increased due to the effects of the growth regulator. The dry matter partition of plants changed in plants subjected to the growth regulator, with a delay in the targeting of assimilates to reproductive organs and a greater allocation to roots at the end of the cycle in plants subjected to the doses 0.50 and 0.75 L·ha-1 of growth regulator. Seed vigor was adversely affected by the growth regulator.
