scholarly journals Effect of Planting Density on Fruit Size, Light-Interception and Photosynthetic Activity of Vertically Trained Watermelon (Citrullus lanatus (Thunb.) Matsum. et Nakai) Plants

2003 ◽  
Vol 72 (6) ◽  
pp. 497-503 ◽  
Author(s):  
Shin-ichi Watanabe ◽  
Yuka Nakano ◽  
Kunio Okano
Keyword(s):  
Photosynthetic Activity ◽  
Citrullus Lanatus ◽  
Fruit Size ◽  
Light Interception ◽  
Planting Density

scholarly journals 589 Summer Pruning Effects on Leaf and Whole Canopy Gas Exchange in Apple Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 548C-548
Author(s):  
Kuo-Tan Li ◽  
Alan N. Lakso
Keyword(s):  
Photosynthetic Activity ◽  
Fruit Size ◽  
Light Interception ◽  
Light Penetration ◽  
Apple Trees ◽  
Carbon Supply ◽  
Shade Leaves ◽  
Reduced Light ◽  
Canopy Light Interception

Summer pruning is primarily used in apples to increase the light penetration into inner canopy to improve fruit color. However, summer pruning may reduce fruit size. We hypothesize that removing healthy exterior shoots reduces the whole-tree carbon supply in relation to pruning severity. If the crop load (i.e., demand) is high, fruit size and quality will be reduced. The effects of summer pruning on photosynthetic activity and recovery of shaded leaves after re-exposure were monitored on a range of exposures in canopies of `Empire' apple trees. The photosynthetic ability of leaves was positively related to its prepruning exposure. There was little recovery of photosynthetic activity of shade leaves until late growing season, indicating the re-exposure of shade leaves after summer pruning cannot replace the role of exterior leaves removed by pruning. Whole canopy net CO2 exchange (NCER) was measured on `Empire'/M9 trees with a commercial range of pruning severity. Reductions in NCER were approximately proportional to pruning severity and % leaf area removed and were as great as 60% in the most severe pruning. Canopy light interception decreased slightly. The effects on canopy NCER thus appeared to be primarily related to reduced photosynthetic efficiency and secondarily to reduced light interception.

Growth, yield and preliminary selection of seedling guavas in Queensland

1981 ◽  
Vol 21 (108) ◽  
pp. 119
Author(s):  
KR Chapman ◽  
B Paxton ◽  
J Saranah ◽  
PD Scudamore-Smith
Keyword(s):  
Crop Yields ◽  
Fruit Size ◽  
Growth Yield ◽  
Cross Sectional Area ◽  
Planting Density ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fruit Number ◽  
Quality Aspects ◽  
Preliminary Selection

Five guava seedlines of Hawaiian origin, namely GA9-37, GA12-1 6, GA10-48, GA11-56 and GA9-39 were yield tested in coastal sub-tropical south-eastern Queensland. The work demonstrated that seedling guavas produce attractive yields comparable with overseas countries. First crop mean yields were 30.72 kg/tree after 18 months in the field, demonstrating the precocious bearing of the guava. Yields for second and third cropping years were 45.6 and 77.9 kg/tree. These yields equate to 24.7, 37.2 and 61.5 tonnes ha-1 at a planting density of 805 trees ha-1. Third crop yields give the attractive gross returns of around $15,000 ha-1, at current prices paid by processors in Queensland. No differences were found between seedlines in annual yields, accumulated crop yields, fruit Number/tree, annual yield per unit cross sectional area of butt (an index of fruitfulness) and accumulated yield per unit cross sectional area of butt. Within seedline, variability masked differential response and these aspects are discussed. Fruit yields and relative increase in butt cross sectional area of butt varied with cropping year. Fruit. number per tree and yield per unit cross sectional area of butt varied with years, as did fruit number per kg (an index of fruit size). The latter also varied with seedlines. These effects were attributed to water rationing in spring of the second crop year. Preliminary selection based on fruit quality aspects of individuals identified four individuals which are undergoing detailed processing assessment, namely GA9-39R1T2, GA11-56T7, GA11-56R5T2 and GA1 1-56R5T1. Two further individuals were selected for fresh fruit market testing, namely GA11-56T3 and GA11 -56R1T1. We believe that market development rather than horticultural problems to be overcome will dictate the success of the guava as a crop for Australia, since the guava is comparatively easy to grow and manage.

scholarly journals Effect of Spatial-Temporal Light Competition on Cotton Yield and Yield Distribution

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2346
Author(s):  
Qingru Wang ◽  
Huanxuan Chen ◽  
Yingchun Han ◽  
Fangfang Xing ◽  
Zhanbiao Wang ◽  
...  
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Retention Rate ◽  
Block Design ◽  
Light Interception ◽  
Planting Density ◽  
Cotton Yield ◽  
Light Competition ◽  
Area Index ◽  
Yield Distribution

The photosynthetically active radiation (PAR) of crop canopy is highly related to yield formation, but how it relates to yield and yield distribution is not well understood. The focus of this study was to explore the relationship between light competition under different densities and yield distributions of cotton. The experiment was conducted in 2019 and 2020 at the Cotton Research Institute of the Chinese Academy of Agricultural Sciences in Anyang city, Henan Province, China. A randomized block design was employed, with a total of three repeats. Each repeat had six density treatments: D1: 15,000; D2: 33,000; D3: 51,000; D4: 69,000; D5: 87,000; and D6: 105,000 plants·ha−1. As predicted, the results showed that the canopy light interception, leaf area index, plant height, and biomass of high-density cotton were higher than those of low-density cotton. The aboveground biomass produced by D6 was the highest, and was 12.9, 19.5, 25.4, 46.3, and 69.2% higher in 2019 and 14.3, 19.9, 32.5, 53.7, and 109.9% higher in 2020 than D5, D4, D3, D2, and D1, respectively. Leaf area, plant height, biomass, boll number, and boll weight were significantly correlated with the light interception rate. D5 (87,000 plants·ha−1) had a higher light interception rate and the highest yield. The highest lint yields produced by D5 were 1673.5 and 1375.4 kg·ha−1 in two years, and was 3.2, 4.3, 5.6, 9.7, and 24.7% higher in 2019, and 6.8, 10.6, 13.5, 21.5, and 34.4% higher in 2020 than D6, D4, D3, D2, and D1, respectively. The boll retention of the lower fruit branch under D5 reached 0.51 and 0.57 in two years, respectively. The shedding rate of the upper fruit branch decreased with the increase in cotton density in two years. The boll retention rate and shedding rate in the lower part of cotton plants were most closely related to light interception, with R2 values of 0.91 and 0.96, respectively. Our study shows cotton yield could be improved through higher light interception by optimizing planting density and canopy structure.

scholarly journals QUALIDADE E PRODUTIVIDADE DE FRUTOS DE FIGO CULTIVADO EM TRÊS DENSIDADES DE PLANTIO

2018 ◽  
Vol 14 (4) ◽  
pp. 161-166
Author(s):  
Scheila Lucia Ecker ◽  
Clevison Luiz Giacobbo ◽  
Leandro Galon ◽  
Adriana Lugaresi ◽  
Gian Carlos Girardi
Keyword(s):  
Fruit Quality ◽  
Dry Matter ◽  
Fruit Size ◽  
Dry Mass ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Planting Density ◽  
Significant Difference ◽  
Fig Tree

The objective of this work was to verify the influence of planting density on productivity and fruit quality of the fig tree. The design was used in three blocks, the plants of the cultivar Roxo de Valinhos were submitted to three planting spacings: 5 x 0.5 m; 5 x 1.0 m; and 5 x 1.5 m. The evaluated characteristics were: length of branches; average weekly growth of branches; fruit size; average fruit weight;soluble solids (°Brix); yield of mature fruits; productivity of green fruits; accumulated productivity; and dry mass of fruits.The length of the branches was not influenced by planting spacing, the plants conducted at lower densities presented higher productivity, both of green fruits and accumulated productivity.Plants submitted to lower planting density produced fruits with higher dry matter, but these were smaller in size, but without significant difference for those submitted to lower density. It wasconcluded that productivity is directly affected by fig planting density, but not all the qualitative aspects of the fruits were affected.

scholarly journals High Density and Uniform Plant Distribution Improve Soybean Yield by Regulating Population Uniformity and Canopy Light Interception

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1880
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Light Interception ◽  
Plant Distribution ◽  
Planting Density ◽  
Dry Matter Accumulation ◽  
Plant Spacing ◽  
Soybean Yield ◽  
The Relationship ◽  
Canopy Light Interception

Optimizing the spatial distribution of plants under normal conditions of water and fertilizer is widely used by farmers to improve soybean yield. However, the relationship between soybean yield and spatial plant distribution in the field has not been well studied. This study examined the effect of planting density and plant distribution pattern on soybean plant growth, yield components, canopy light interception, and dry matter accumulation. We also analyzed the relationship between photosynthetic rate, dry matter accumulation, and yield under different planting densities and plant distribution. A two year field experiment was conducted during the 2018 and 2019 soybean planting seasons. Two planting densities (1.8 × 105 and 2.7 × 105 plants ha−1) and two plant distribution patterns (uniform and non-uniform plant spacing) were tested. Higher planting density significantly increased the canopy light interception and dry matter accumulation during soybean growth, leading to increased soybean productivity. The seed yield of soybean under higher planting density was 22.8% higher than under normal planting density. Soybean planted under uniform spacing significantly reduced the differences plant-to-plant. Uniform plant spacing significantly increased the canopy light interception and dry matter accumulation of the soybean population. In addition, the coefficient of variation of seed weight per plant between individual plants under uniform plant distribution decreased by 71.5% compared with non-uniform plant distribution. Furthermore, uniform plant distribution increased soybean seed yield by 9.5% over non-uniform plant distribution. This study demonstrates that increasing planting density under uniform plant distribution can be useful to obtain higher seed yield without increasing other farm inputs.

scholarly journals Interpretation and Evaluation of Electrical Lighting in Plant Factories with Ray-Tracing Simulation and 3D Plant Modeling

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1545
Author(s):  
Jaewoo Kim ◽  
Woo Hyun Kang ◽  
Jung Eek Son
Keyword(s):  
Ray Tracing ◽  
Crop Production ◽  
Light Interception ◽  
Light Distribution ◽  
Planting Density ◽  
Environment Design ◽  
Photosynthetic Rates ◽  
Architecture Model ◽  
Light Intensities ◽  
Ray Tracing Simulation

In plant factories, light is fully controllable for crop production but involves a cost. For efficient lighting, light use efficiency (LUE) should be considered as part of light environment design. The objectives of this study were to evaluate and interpret the light interception, photosynthetic rate, and LUE of lettuces under electrical lights using ray-tracing simulation. The crop architecture model was constructed by 3D scanning, and ray-tracing simulation was used to interpret light interception and photosynthesis. For evaluation of simulation reliability, measured light intensities and photosynthetic rates in a growth chamber were compared with those obtained by simulation at different planting densities. Under several scenarios modeling various factors affecting light environments, changes in light interception and LUE were interpreted. The light intensities and photosynthetic rates obtained by simulation showed good agreement with the measured values, with R2 > 0.86. With decreasing planting density, the light interception of the central plant increased by approximately 18.7%, but that of neighboring plants decreased by approximately 5.5%. Under the various scenarios, shorter lighting distances induced more heterogenetic light distribution on plants and caused lower light interception. Under a homogenous light distribution, the light intensity was optimal at approximately 360 μmol m−2 s−1 with an LUE of 6.5 g MJ−1. The results of this study can provide conceptual insights into the design of light environments in plant factories.

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