scholarly journals Response of Nagpur mandarin (Citrus reticulata Blanco) to high density planting systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. S. Ladaniya ◽  
R. A. Marathe ◽  
A. A. Murkute ◽  
A. D. Huchche ◽  
A. K. Das ◽  
...  

AbstractHigh density planting system i.e. accommodating a higher number of plants than routine in a given area is an innovative agro-technology to increase yield and thereby early net returns. Due to conventional wide spacing plantation in Nagpur mandarin (Citrus reticulata Blanco), the land remains unutilized as the plant canopy gradually increases over the years. In the present study, Nagpur mandarin (Citrus reticulata Blanco) budded on Rangpur lime rootstock was evaluated under six different planting spacings. It was observed that the organic carbon (1.10–1.82%) and major nutrients viz. N (309–430 kg ha−1), P (20–54 kg ha−1) and K (291–810 kg ha−1) increased vis-à-vis plant density and was highest under 2 × 2 m spacing. Plants were tallest at 2 × 2 m spacing with the higher PAR interception (88.2) and the lowest leaf area index (1.09). Fruit yield on area basis, under 2 × 2 m spacing was 26, 7.1, 4.6 times more as compared to conventional plantation during the first, second and third year, respectively. At fifth year of crop harvest, the highest B:C ratio (6.36) was recorded in 6 × 3 m followed by 4 × 2 m and 2 × 2 m.

Author(s):  
Y. Siva Lakshmi ◽  
D. Sreelatha ◽  
T. Pradeep

A field experiment was conducted at the Maize Research Centre, Agricultural Research Institute (ARI), Rajendranagar, Hyderabad during the rabid seasons (15 October to 15 January) for two years to study the effect of plant densities and nitrogen levels on growth parameters, yield characteristics, yield and economics of the newly published popcorn hybrid BPCH-6 by Professor Jayashankar Telangana State Agri-6 (Previously Acharya NG Ranga Agricultural University). Three plant densities (P1–1,11,111 ha-1 (60 x 15 cm), P2–1,11,111 ha-1 (45 x 20 cm) and P3–83,333 ha-1 (60 x 20 cm) and four levels of nitrogen (N1–80 kg ha-1, N2–120 kg ha-1, N3–160 kg ha-1 and N4–200 kg ha-1) were taken in a randomised block configuration with three repeated factorial principles.  Significantly higher plant height with a population of 1, 11,111 ha-1 (45x20 cm), significantly higher leaf area index with a population of 1, 11,111 ha-1 (60x15 cm) and significantly higher dry matter production (g plant-1) with a population of 83,333 plants ha-1 (60x20 cm) was observed as per pooled mean over two years.  Yield attributes like cob girth, number of rows cob-1 and 100 seed weight were not influenced significantly whereas cob length and number of seeds row-1 were significantly superior with optimum plant density of 83,333ha-1. A plant density of 1, 11,111 ha-1 (60x15 cm).  recorded significantly higher cob, grain fodder yields. When a population of 1, 11,111 plants ha-1 (60x15 cm) was maintained, gross and net returns and profit cost ratios were higher. The use of 200 kg of nitrogen ha-1 resulted in slightly higher growth parameters, yield characteristics and yield, but it was equal to 160 kg of N ha-1  and both were greater than 120 and 80 kg of N ha-1.. Application of 160 Kg N ha-1 recorded higher gross and net returns and benefit cost ratio compared to 200 Kg N ha-1.


2002 ◽  
Vol 20 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Miguel A. Sandri ◽  
Jerônimo L. Andriolo ◽  
Márcio Witter ◽  
Tiago dal Ross

Tomato fruit setting on high density defoliated tomato plants with similar leaf area index was determined in three environmental conditions, inside polyethylene tunnels. Experiment 1 was carried out in autumn when average solar radiation received by the crop was 8.0 MJ m-2 day-1. Average external temperature was 18.1ºC. Experiments 2 and 3 were conducted in spring, when average external temperature was 19.7ºC. In experiment 2, average solar radiation received by the crop was 12.4 MJ m-2 day-1, whereas in experiment 3 it was reduced to 5.9 MJ m-2 day-1 by a 52% shading net. Plants were grown in bags, spaced 1.0 m between row and 0.3 m within row bags distance, using 5.5 L of a commercial substrate. Nutrients and water were supplied by means of a nutrient solution, delivered daily in order to replace volumes lost by transpiration. Treatments consisted of one (T1), two (T2) and three (T3) plants per bag, leading to plant densities of 3.3, 6.7 and 10 plants m-2, respectively. In T1, three leaves per sympod were kept, with a ratio of 3:1 between number of leaves and inflorescences per sympod. In T2, two and one leaf was kept respectively on two consecutive sympods, alternatively on both plants. The ratio between number of leaves and inflorescences was 3:2. In T3, with three plants per bag, only one leaf per sympod was kept on each plant. The ratio between number of leaves and inflorescences was 3:3. In all experiments, the number of trusses per area in T2 and T3 was two and three times higher than in T1, respectively. The number of fruits per unit ground area was lower in T1 plants and similar in T2 and T3 plants in the first experiment, whereas in the second and third experiments similar values were observed among treatments. Results indicated that tomato plants adjust the number of fruits, and exceeding flowers are aborted. The use of a plant density of 6.7 plants m-2 combined with a 3:2 ratio between number of leaves and inflorescences per unit ground area seems to be the upper limit in maximizing the number of set fruits of this crop.


2017 ◽  
Vol 9 (3) ◽  
pp. 1835-1839 ◽  
Author(s):  
M. Y. Ajayakumar ◽  
M. R. Umesh ◽  
Shivaleela Shivaleela ◽  
J.M. Nidagundi

Plant density and optimum fertilization are two important agronomic practices to enhance productivity of cotton (Gossypium hirsutum L.) varieties. The objective of this study was to investigate the effect of high density planting (HDPS) and fertilization rate, especially their interactions, on yield, yield components of cotton varieties in sub-tropical India. Split-split plot design was adopted and replicated thrice. The main plots were assigned to low, medium and high plant densities (16.7, 13.3 and 11.1 plants/m2). Pre released cotton varieties TCH-1705 and LH-2298 were tested in low, moderate and high rates of fertilizers recommended for the region (100, 125 and 150 %) in sub-sub plots. Significantly higher seed cotton yield (1148 kg/ha) was achieved in narrow inter row spaced at 60 cm over normal plant row spacing of 90 cm (1025 kg/ha). Compact genotype TCH-1705 was out yielded (1146 kg/ha) over LH 2298(1044 kg/ha). Application of fertilizers at higher rate improved seed cotton yield (1232 kg/ha) Leaf area index (3.8) and light interception (0.98) over blanket recommendation. The results of the study inferred that seed cotton yield improvement was possible under HDPS production system with compact varieties grown at narrow spacing and higher fertilizer dose.


2021 ◽  
Vol 11 (11) ◽  
pp. 4995
Author(s):  
Marco Custódio ◽  
Paulo Cartaxana ◽  
Sebastián Villasante ◽  
Ricardo Calado ◽  
Ana Isabel Lillebø

Halophytes are salt-tolerant plants that can be used to extract dissolved inorganic nutrients from saline aquaculture effluents under a production framework commonly known as Integrated Multi-Trophic Aquaculture (IMTA). Halimione portulacoides (L.) Aellen (common name: sea purslane) is an edible saltmarsh halophyte traditionally consumed by humans living near coastal wetlands and is considered a promising extractive species for IMTA. To better understand its potential for IMTA applications, the present study investigates how artificial lighting and plant density affect its productivity and capacity to extract nitrogen and phosphorous in hydroponic conditions that mimic aquaculture effluents. Plant growth was unaffected by the type of artificial lighting employed—white fluorescent lights vs. blue-white LEDs—but LED systems were more energy-efficient, with a 17% reduction in light energy costs. Considering planting density, high-density units of 220 plants m−2 produced more biomass per unit of area (54.0–56.6 g m−2 day−1) than did low-density units (110 plants m−2; 34.4–37.1 g m−2 day−1) and extracted more dissolved inorganic nitrogen and phosphorus. Overall, H. portulacoides can be easily cultivated hydroponically using nutrient-rich saline effluents, where LEDs can be employed as an alternative to fluorescent lighting and high-density planting can promote higher yields and extraction efficiencies.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 313
Author(s):  
Guoqiang Zhang ◽  
Bo Ming ◽  
Dongping Shen ◽  
Ruizhi Xie ◽  
Peng Hou ◽  
...  

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.


Author(s):  
L. S. Sampaio ◽  
R. Battisti ◽  
M. A. Lana ◽  
K. J. Boote

Abstract Crop models can be used to explain yield variations associated with management practices, environment and genotype. This study aimed to assess the effect of plant densities using CSM-CROPGRO-Soybean for low latitudes. The crop model was calibrated and evaluated using data from field experiments, including plant densities (10, 20, 30 and 40 plants per m2), maturity groups (MG 7.7 and 8.8) and sowing dates (calibration: 06 Jan., 19 Jan., 16 Feb. 2018; and evaluation: 19 Jan. 2019). The model simulated phenology with a bias lower than 2 days for calibration and 7 days for evaluation. Relative root mean square error for the maximum leaf area index varied from 12.2 to 31.3%; while that for grain yield varied between 3 and 32%. The calibrated model was used to simulate different management scenarios across six sites located in the low latitude, considering 33 growing seasons. Simulations showed a higher yield for 40 pl per m2, as expected, but with greater yield gain increments occurring at low plant density going from 10 to 20 pl per m2. In Santarém, Brazil, MG 8.8 sown on 21 Feb. had a median yield of 2658, 3197, 3442 and 3583 kg/ha, respectively, for 10, 20, 30 and 40 pl per m2, resulting in a relative increase of 20, 8 and 4% for each additional 10 pl per m2. Overall, the crop model had adequate performance, indicating a minimum recommended plant density of 20 pl per m2, while sowing dates and maturity groups showed different yield level and pattern across sites in function of the local climate.


1975 ◽  
Vol 15 (72) ◽  
pp. 136 ◽  
Author(s):  
MC Stannard ◽  
JC Evans ◽  
JK Long

Washington navel orange trees on trifoliate orange rootstocks were inoculated at various ages with budwood from either severely dwarfed Washington navel trees with butt scaling caused by exocortis virus or moderately dwarfed Marsh grapefruit trees with no butt scaling. Dwarfing, measured by trunk girth, became apparent four seasons after inoculation, the butt scaling inoculum causing more pronounced dwarfing than the non-scaling inoculum. For both inocula, trees inoculated in the nursery were the most dwarfed, and yielded least, with trees inoculated in the field one, two, three or five years later being successively less dwarfed and high yielding. In a second experiment, Washington navel orange trees on trifoliate orange, which were carrying exocortis virus or were inoculated with it either in the nursery or later in the field, were planted in 1962 at a density of 835 ha-1. The field inoculated trees subsequently grew larger than the others. All were more dwarfed but yielded more heavily on a ground area basis during five years of cropping than exocortis-free trees planted at a normal density of 222 ha-1. Dwarfed trees developed butt scaling symptoms and periodically became unthrifty. The non-scaling form of dwarfing lends itself to the development of high density plantings of small trees with consequent benefits in management and high early production


2015 ◽  
Vol 10 (3) ◽  
pp. 163 ◽  
Author(s):  
Rocco Bochicchio ◽  
Roberta Rossi ◽  
Rosanna Labella ◽  
Giovanni Bitella ◽  
Michele Perniola ◽  
...  

The demand for sources of nutraceuticals has led to the rediscovery and diffusion of traditional crops such as chia (<em>Salvia hispanica</em> L.), whose leaves and fruits are rich in W3 fatty acids and anti-oxidants. Chia originates in Central America but it is rapidly expanding to new areas. A field experiment conducted at Atella in Basilicata (Southern Italy) was set up to test the response of chia to N top-dress fertilisation (0 and 20 kg ha<sup>–1</sup>) and to sowing density (D1=125, D2=25, D3=8 and D4=4 plants m<sup>–2</sup>) in a split-plot design with three replications. First results show maximum leaf area index values up to 7.1 and fresh vegetative biomass production at early flowering ranging between 50.87 (D4) and 59.71 (D1) t ha<sup>–1</sup>. Yield increased with plant density: a significantly (P&lt;0.01) higher production (398 kg ha<sup>–1</sup>) was reached in D1. N top-dressing had a detrimental effect on yield and corresponded to higher lodging and lower maturation percentage of seeds, though non-significant. Based on our first results it seems worthwhile to continue agronomical trials for chia in herbaceous systems of southern Italy for leaf production based on traditional genotypes, while fruit production might be pursued by adopting high sowing density and the search for longer-day genotypes.


1999 ◽  
Vol 124 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Frank D. Moore

A simulation model was built as a decision aid for management of five weed species in direct seeded irrigated onion (Allium cepa L.). The model uses the state variable approach and simulations are driven by temperature and sunlight as photosynthetically active radiation (PAR). It predicts yield reduction caused by competition for PAR according to the ratio of crop leaf area index (LAI) to weed LAI and respective light extinction coefficients (k). Input variables are plant density by species and average number of leaves by species. Number of leaves per plant is used by the model to provide an estimate of initial leaf area per plant. The model calculates initial species LAIs by multiplying species density times average leaf area per plant. The model accurately describes competitive interactions, taking into account respective plant densities, time of emergence, and time of weed removal. It permits economic evaluation of management factors such as handweeding, chemical weed control, herbicide phytotoxicity due to early application, and control of weed flushes during the season. The model is also used to evaluate mechanisms of plant competition for sunlight. In a sensitivity analysis, onion yield loss was more sensitive to weed PAR interception than to PAR use efficiency, the latter a species-dependent constant in the model.


Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 284
Author(s):  
Ana Laura Pereira Souza ◽  
Marcelo Marques Costa ◽  
Darly Geraldo de Sena Junior ◽  
Rogério Borges de Oliveria Paz

O Índice de área foliar (IAF) representa a eficiência na interceptação e utilização da radiação solar pelas plantas. O IAF pode ser obtido de forma direta, determinando-se a área foliar e área ocupada pela planta. Entretanto, métodos indiretos são comumente utilizados para sua estimativa devido a necessidade de praticidade. O objetivo deste trabalho foi avaliar a equivalência das estimativas do IAF obtidas por meio de um ceptômetro, pelo método de discos e utilizando imagens digitais. Para tanto, foi conduzido um experimento com a cultura da soja, no delineamento em blocos casualizados, com variação da densidade de plantas, para comparar os valores de IAF obtidos pelos diferentes métodos aos 34 dias após a semeadura (DAS). A comparação foi feita por meio dos coeficientes de equações lineares ajustadas entre os resultados obtidos. O método do disco e do ceptômetro, apresentaram uma boa equivalência entre seus valores. Entretanto, o método que utiliza imagens superestimou o IAF, não apresentando uma boa equivalência de seus valores aos do método de discos e ao ceptômetro.Palavras-chave: ceptômetro, discos foliares, imagens digitais. EVALUATION OF THREE OBTAINMENT METHODS OF FOLIAR AREA INDEX FOR SOYBEAN CROP ABSTRACT:The leaf area index (LAI) represents the interception efficiency and use of solar radiation by plants. IAF can be obtained directly, determining the leaf area and area occupied by the plant. However, indirect methods are commonly used for their estimation because for practicality. The objective of this work was to evaluate the equivalence of the LAI estimates obtained with a ceptometer, using the disc method and digital images. A experiment was conducted with soybean crop, in a randomized block design with plant density variation to compare the LAI values obtained by the different methods at 34 days after sowing (DAS). The comparison was made through the coefficients of linear equations adjusted between the results obtained. The disc and the ceptometer method presented a good equivalence between their values. However, the imaging method overestimated the LAI, not presenting a good equivalence of its values to those of the disc method and the ceptometer.Keywords: ceptometer, leaf discs, digital images.


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