ABSTRACT
Increasing the seeding belt width from 2 to 3 cm (conventional drilling sowing, CD) to 8-10 cm (wide belt sowing, WB) can markedly improve the grain yield of bread wheat. However, there are insufficient data to explain how WB affects dry matter (DM) remobilization, pre- and post-anthesis production, and ultimately grain weight and grain yield. In the present study, four bread wheat cultivars (Jimai44, Taishan27, Gaoyou5766, and Zhouyuan9369) with similar phenology characteristic were selected as experimental materials and two sowing patterns (CD and WB) were applied during the 2018-2019 and 2019-2020 growing seasons, to investigate the effects of sowing pattern on grain yield and its components of bread wheat. The results showed that WB increased the post-anthesis rate of canopy apparent photosynthesis (CAP) in comparison with CD, by 19.73-133.68%, across the two seasons and four bread wheat cultivars. Furthermore, WB significantly increased the activities of superoxide dismutase, peroxidase, and catalase, and decreased the malondialdehyde content of the flag and penultimate leaf, thereby extending the duration of the high-value CAP period by 1.95-2.51 days. The improved rate and duration of CAP in WB led to an increase in post-anthesis DM production of 13.33-23.58%, thus ensuring DM distribution to the grain of each bread wheat cultivar. Consequently, in WB, the grain weight was maintained, the grain yield was increased markedly by 9.65-15.80%, at the backdrop of increases in spike number and in turn grain number per unit area. In summary, WB could be applied widely to obtain a high yield of bread wheat.
ABSTRACT
Pearl millet is an important crop for food security in Asia and Africa's arid and semi-arid regions. It is widely grown as a staple cereal grain for human consumption and livestock fodder. Mechanistic crop growth and water balance models are useful to forecast crop production and water use. However, very few studies have been devoted to the development of the model parameters needed for such simulations for pearl millet. The objectives of the study were to determine crop-specific model parameters for each of three pearl millet varieties (landrace, hybrid, and improved), as well as to calibrate and validate the Soil Water Balance (SWB) model for predicting pearl millet production and water use based on weather data. The SWB was chosen because it is widely used in southern Africa; however, the developed parameters should benefit other models as well. The presented crop-specific parameter values were derived from field observations and literature. Varieties with different phenology, maturity dates and tillering habits were grown under well-watered and well-fertilised conditions for calibration purposes. The calibrated model was used to predict biomass production, grain yield and crop water use. The hybrid's water use efficiency was higher than that of the landrace and improved variety.
ABSTRACT
sd1-d has been utilized to develop short-culmed indica varieties adaptable to higher fertilizer-applications. Its tall alleles SD1-in and SD1-ja are harbored in indica and japonica subspecies, respectively. SD1-in possesses a higher effect on elongating culm than SD1-ja. The sd1-d of indica IR36 was substituted with SD1-in or SD1-ja through recurrent backcrossing with IR36, and two tall isogenic lines ("5867-36" and "Koshi-36") were developed. IR36, 5867-36 and Koshi-36 were grown in a paddy field, and the effects of sd1-d, SD1-in and SD1-ja on morphological characteristics concerning dry-matter production and photosynthesis were compared mutually. sd1-d diminished dry weight of total brown rice/m2 and total dry matter weights, but enhanced harvest indexes, compared with SD1-in. In IR36, shorter lengths of the first (flag) to third leaves, and more panicle-bearing stems, caused by sd1-d, compared with SD1-in-carrying 5867-36, and erect first leaves, not caused by sd1-d, could construct the canopy structure appropriate for obtaining a high rate of photosynthesis at an optimum LAI. Koshi-36 could be used for a mid-mother line to develop indica varieties adaptable to middle and low fertilizer-applications, due to higher effect of SD1-ja on yielding ability, compared with that of sd1-d, no breaking-type lodging, and resistances to diseases and pests.
ABSTRACT
Managements of organic matter and irrigation after anthesis will increase the capacities of water conservation and supply in maize field, with consequences on photosynthetic performance and yield under water-saving condition. We analyzed the gas exchange parameters and the performance of the photosystem 2 of ear leaves, and yield of maize cultivars Zhengdan 958, under three modes of ditch-buried organic matter (no straw returned: M0, wheat straw returned: M1, mixtures of cow manure and wheat straw returned: M2) before seeding with two irrigation levels after anthesis (normal irrigation: W1, water-saving irrigation: W2). The results showed that M2 treatment significantly increased photosynthetic capacity and dry matter accumulation after anthesis compared with M1 treatment. Compared with water-saving irrigation, normal irrigation enhanced the photosynthesis of ear leaves. M2W1 treatment significantly increased net photosynthetic rate (Pn), stomatal conduc-tance (gs), transpiration rate (Tr), and performance of photosystem 2 (Φpo and ωo) of ear leaves after anthesis, while reduced intercellular CO2 concentration (Ci). In addition, M2W1 treatment significantly increased light utilization efficiency and maintained higher photosynthetic properties in ear leaves, and significantly increased dry matter accumulation and grain yield. Water-saving irrigation reduced photosynthetic performance of ear leaves, which declined the yield. But compared M2 with M0, water use efficiency, grain growth rate and yield increment under water-saving irrigation were higher than those under normal irrigation. Thus, mixtures of cow manure and wheat straw returned combined with normal irrigation could significantly increase photosynthetic properties of ear leaves and dry matter accumulation, which were the major reasons for yield enhancement. Importantly, the mixture of cow manure and wheat straw returned combined with water-saving irrigation could decrease the loss of crop yield resulted from lower irrigation.
Subject(s)
Agricultural Irrigation , Photosynthesis , Zea mays , Animals , Biomass , Cattle , Edible Grain , Female , Plant Leaves , Poaceae , Triticum , WaterABSTRACT
Este estudo teve como objetivo avaliar o efeito de diferentes intervalos entre pastejos sobre as características produtivas de trevo-persa e azevém, consorciados e manejados sob lotação rotacionada, nos anos de 2009 e 2010. Os tratamentos consistiram em quatro intervalos entre pastejos (tempo para o surgimento de 2,5; 3,5; 4,5 e 5,5 folhas em plantas de trevo-persa), em delineamento de blocos completos ao acaso, com seis repetições. As variáveis analisadas foram: índice de área foliar, área foliar, altura do pasto e de plantas, comprimento de perfilhos/ramificações, taxa de acúmulo de matéria seca e produção de matéria seca. O índice de área foliar do dossel e do trevo-persa foi maior no intervalo de 5,5 folhas nos anos de 2009 e 2010. No ano de 2009, maiores valores de área foliar foram obtidos nos intervalos de 3,5 e 4,5 folhas e não se observou efeito dos intervalos entre pastejos sobre essa variável em 2010. Maiores intervalos entre pastejos proporcionaram maior altura do pasto e de plantas e também maior comprimento de perfilhos e ramificações. A produção de matéria seca do trevo-persa foi maior em 2010, ao passo que, para azevém, maior produção foi encontrada em 2009. A produção de matéria seca total foi maior no intervalo de 5,5 folhas. A taxa de acúmulo de matéria seca foi maior no intervalo de 5,5 folhas em 2009 e no intervalo de 2,5 folhas em 2010. As características produtivas da consorciação trevo-persa e azevém anual são modificadas pelos intervalos entre pastejos. Recomendam-se intervalos de até 3,5 folhas surgidas, em consorciação de trevo-persa e azevém anual, os quais proporcionam menor alongamento de caules associado à menor presença de material morto, o que, provavelmente, melhora a qualidade da forragem colhida.
The aim of this trial was to study the effect of different grazing intervals on productive characteristics of persian clover and ryegrass, in consortium and managed under rotational stocking during the years 2009 and 2010. Treatments were composed of four grazing intervals (time to onset of 2.5; 3.5; 4.5 and 5.5 leaves in persian clover plants) allocated in completely randomized blocks, with six replications. Leaf area index (LAI), leaf area, pasture and plants height, length of tillers/branches, rate of dry matter accumulation and dry matter yield were evaluated. The leaf area index of the canopy and the persian clover was higher in the interval of 5.5 leaves in years 2009 and 2010. In 2009, higher values of leaf area were obtained in intervals of 3.5 and 4.5 leaves and there no was effect of grazing intervals on this variable in 2010. Higher grazing intervals provided greater pasture height and plant height and also greater tiller and branch length. The dry matter production of persian clover was higher in 2010, while for ryegrass highest yields were found in 2009. Total dry matter yield was higher in the interval of 5.5 leaves. The rate of dry matter accumulation was higher in the interval of 5.5 leaves in 2009 and in the interval of 2.5 leaves in 2010. The productive characteristics of a of mixture persian clover and ryegrass are modified by the grazing intervals. It is recommended intervals up to 3.5 of appeared leaves with a mixture of persian clover and ryegrass, which provides lower elongation of stems associated with a lower presence of dead material, which probably improves the quality of the harvested forage.
Subject(s)
Pasture/analysis , Pasture/economics , EfficiencyABSTRACT
RESUMO A espécie Physalis angulata L., pertencente à família Solanaceae, tem despontado como uma planta extremamente promissora para uso medicinal, em razão da produção do composto fisalina. No entanto, aspectos importantes do seu cultivo ainda permanecem pouco conhecidos. Assim, objetivou-se avaliar a influencia do fósforo para o seu crescimento. O experimento foi conduzido em Latossolo Amarelo de textura média, submetido a três doses de P: 8, 16 e 64 mg kg-1 de P. Usou-se um delineamento experimental inteiramente casualizado. Foram realizadas duas colheitas: aos 30 e 42 dias após o plantio. Verificou-se que as plantas cultivadas sob deficiência (8 mg kg-1 de P no solo) apresentaram 26,3 folhas, enquanto as cultivadas com a maior dose (64 mg kg-1 de P no solo) produziram 80,17 folhas. Aumento semelhante (201%) foi obtido para a área foliar, cujos valores variaram de 436,4 cm2a 1.313,9 cm2. Sob deficiência, a produção da massa seca total foi de apenas 1,72g, enquanto para a dose de 64 mg kg-1 de P no solo esse valor foi de 7,58g, significando um aumento de 340%. Plantas cultivadas com 8 mg kg-1 de P no solo não apresentaram flores ou frutos; já para o tratamento em que se utilizou 64 mg kg-1 de P no solo, o início do florescimento antecedeu ao das plantas cultivadas com 16 mg kg-1 de P no solo. A razão de área foliar e a área foliar específica foram maiores para as plantas cultivadas sob deficiência, enquanto a taxa de crescimento relativo e a taxa assimilatória líquida não foram estatisticamente influenciadas. Conclui-se que a deficiência de P no solo pode comprometer sobremaneira o crescimento das plantas de Physalis. Além disso, como a deficiência de P reduziu sensivelmente a produção de folhas, órgão responsável pela produção da fisalina, também é possível concluir que a deficiência de P pode, mesmo que indiretamente, reduzir a concentração desse importante composto na planta.
ABSTRACT The specie Physalis angulata L., who belongs to the Solanaceae family, has stand out as an extremely promising plant in terms of medical use, due to the production of the physalin compound. However, important aspects of its production still remain unknown. Thus the objective of this work was to assess the influence of phosphorus for the growth of these species. The experiment was performed with three doses of P (8, 16 e 64 mg kg-1 de P), in a completely randomized experimental design. Two harvests were performed: at 30 and 42 days after planting. The deficiency of P reduced the number of leaves and leaf area. The total dry matter (DM), as well as a MS from all parts of the plant, was significantly higher for plants grown under the highest levels of phosphorus. Plants grown with 8 mg P kg-1 showed no flowers or fruit; but, for the treatment which used 64 mg of P kg-1 the beginning of flowering happened before than with the plants grown with 16mg. The ratio of the leaf area and the specific leaf area were higher for plants grown under stress, while the values of the relative growth rate and the net assimilatory rate were not statistically influenced. We conclude that the deficiency of P in soil may considerably affect the growth of Physalis plants. Moreover, since the deficiency of P significantly reduced the leaf production, which is responsible for creating the physalin, it is also possible to conclude that P deficiency may, even indirectly, reduce the concentration of this important compound in the plant.
Subject(s)
Physalis/growth & development , Phosphorus/analysis , Plants, Medicinal/metabolism , Crop ProductionABSTRACT
O trabalho foi realizado em propriedades rurais, localizadas nas sub-bacias hidrográficas dos Ribeirões Santa Cruz e Água Limpa, as quais pertencem à bacia do Rio Grande, Lavras, MG, com o objetivo de avaliar e relacionar os atributos físicos do solo com a produtividade das pastagens. Não houve diferenças significativas entre os valores de densidade do solo, porosidade total, micro e macroporosidade nos solos sob os diferentes tipos de pastagens, assim como entre as diferentes profundidades coletadas. O pisoteio animal nestas pastagens, na lotação observada e em sistema de pastejo contínuo, não levou, na camada de 0-10 cm, à obtenção de maiores valores para densidade do solo em relação a subsuperfície. Pela correlação canônica, verificou-se que as produtividades das pastagens mostram associação na sua sensibilidade relacionada aos atributos físicos do solo avaliados.
The work was performed in agricultural properties, located on the hydrographic sub-basins of Santa Cruz and Água Limpa streams, belonging to the Rio Grande basin, Lavras, MG, with the aim of evaluating and relating soil physical attributes with pastures productivity. No differences were observed among bulk density, total porosity, micro and macro-porosity values in soils under different pastures, as well as under different soil samples depths. The animal trampling on these pastures, considering the amount of animals observed in the area and the continuous system of pasture management, did not translate to higher values of bulk density, at 0-10cm depth, and at the subsurface. Through canonical correlation one verified that pastures productivity showed association in its sensibility related to soils physical attributes.