scholarly journals Boll characteristics and yield of cotton in relation to the canopy microclimate under varying plant densities in an arid area

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12111
Author(s):  
Na Zhang ◽  
Liwen Tian ◽  
Lu Feng ◽  
Wenxiu Xu ◽  
Yabing Li ◽  
...  

Planting density affects crop microclimate and intra-plant competition, playing an important role on yield formation and resource use, especially in areas where the cotton is grown at relatively high plant densities in Xinjiang, China. However, more studies are needed to examine how the change in planting density affects the microclimate factors such as the fraction of light intercepted (FLI), air temperature(T) and relative humidity (RH) within different canopy layers, which in turn affect the boll number per plant (BNF), boll number per unit area (BNA), boll weight (BW), and boll-setting rate (BSR) at fruiting branch (FB) positions FB1–3, FB4–6, and FB≥7 in cotton. To quantify the relationships between boll characteristics, yield, and microclimate factors, we conducted a 2-year field experiment in 2019–2020 in Xinjiang with six plant densities: 9 (P1), 12 (P2), 15 (P3), 18 (P4), 21 (P5), and 24 (P6) plants m−2. With each three plants m−2 increase in density, the average FLI and RH across different canopy layers increased by 0.37 and 2.04%, respectively, whereas T decreased by 0.64 °C. The BNF at FB≥ 7, FB4–6, and FB1–3 decreased by 0.82, 0.33, and 0.5, respectively. The highest BNA was observed in the upper and middle layers in the P4 treatment and in the lowest canopy layer with the P5. The highest BW was measured in the middle canopy layer for P3, and the highest BSR was measured in the lower layer for P3. Plant density exhibited linear or quadratic relationships with FLI, T, and RH. Microclimate factors mainly affected the boll number in each layer, but had no significant effects on the BW in any layer or the BSR in the middle and lower layers. Cotton yield was non-linearly related to plant density. The 2-year maximum yield was achieved at a plant density of 21 plants m−2, but the yield increase compared to the yield with a density of 18 plants m−2was only 0.28%. Thus, we suggest that the optimal plant density for drip-irrigated cotton in Xinjiang is 18 plants m−2, which could help farmers grow machine-harvested cotton.

2020 ◽  
pp. 1662-1669
Author(s):  
Marcus Willame Lopes Carvalho ◽  
Edson Alves Bastos ◽  
Milton José Cardoso ◽  
Aderson Soares de Andrade Junior ◽  
Carlos Antônio Ferreira de Sousa

The objectives of this study were to: (i) evaluate the effect of different spatial arrangements on morpho-physiological characteristics and (ii) determine the optimal spatial arrangement to maximize grain yield of the maize hybrid BRS-3046 grown in the Mid-North region of Brazil. We tested two row spacings (0.5 and 1 m) and five plant densities (2, 4, 6, 8, 10 plants m-2), which corresponded to 10 different plant spatial arrangements. Different morphophysiological variables, gas exchange rates and grain yield were measured. The increased planting density led to a linear increase in LAI, regardless of row spacing, while the net CO2 assimilation rate increased until the density of 4 and 6 plants m-2, under a row spacing of 0.5 and 1.0 m, respectively. On the other hand, we found a linear reduction in the stomatal conductance with increasing planting density. The intercellular CO2 concentration and the transpiration rate were higher in the widest row spacing. The instantaneous efficiency of carboxylation, in turn, showed a slight increase up to the density of six plants m-2, then falling, regardless of row spacing. Increasing plant density resulted in a linear increase in plant height and ear insertion height, regardless of row spacing. However, it had an opposite effect on stem diameter. Grain yield, in turn, increased up to 7.3 plants m-2 at a row spacing of 0.5 m and 8 plants m-2 at a row spacing of 1.0 m. This spatial arrangement was considered as ideal for achieving maximum yield


1990 ◽  
Vol 30 (2) ◽  
pp. 257 ◽  
Author(s):  
LJ Wade ◽  
ACL Douglas

The extent and significance of the maturity x density interaction in dryland grain sorghum, and its implications for yield stability, were examined for 3 hybrids over 6 locations. Site mean grain yield ranged from 0.44 to 4.96 t/ha. Early maturity was superior in environments truncated by water stress, while late maturity was superior in favourable environments. Mid-season maturity provided greater stability of grain yield. Maximum yield by each hybrid at each yield level did not differ significantly from yield at a density of 75 000 plants/ha. The highest grain yields should be obtained with plant densities of 50000-100000 plants/ha under rainfed conditions, where yield expectations range from 0 to 5.0 t/ha. The results demonstrate the stability of sorghum grain yield over a wide range of plant density and crop maturity. Regression analysis aided data presentation and interpretation.


2018 ◽  
Vol 13 (4) ◽  
pp. 83-86
Author(s):  
Леонид Шашкаров ◽  
Leonid Shashkarov ◽  
Светлана Толстова ◽  
Svetlana Tolstova

The article deals with the issues of plant density and field germination of winter triticale on gray forest soils of the southeastern part of the Volga-Vyatka zone depending on the variety and seeding rates. The question of establishing the optimum density of sowing, the area of food for grain crops served as the object of study by many researchers. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. The plant stand density and field germination of winter triticale are significantly influenced by the weather conditions formed during the growing season of winter triticale plants. With an increase in seeding rates, the plant stand density and seeding rate increases, respectively, is important for the formation of a given density of productive stalks. In production, these elements of technology are often underestimated and often unjustifiably overestimate the seeding rate, which is absolutely unnecessary, since the really possible yield is achieved at an optimal seeding rate with minimal seed consumption. The winter triticale seeding rates, both in Russia and in the world as a whole varies from 2 to 8 million viable seeds per hectare. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. Until now, there is no consensus on the dependence of planting density on the degree of fertility. Some researchers believe that nutrient-rich soil requires less seed for maximum yield. Under these conditions, the plants develop better, they bush more, the maximum yield can be obtained with a lower seeding rate. The opposite opinion that it is necessary to sow thicker on rich soils has become widespread, especially in recent years. Advocates of the bottom conclusion explain their point of view by the fact that fertile soil has a greater supply of food and moisture, therefore, more plants can be grown on the same area, which means that the seeding rate should be increased [1,2.3,4.5,6,7]. Research results indicate that winter triticale with increasing seeding rates increases plant density and field germination of winter triticale plants.


2021 ◽  
Vol 6 (1) ◽  
pp. 761-770
Author(s):  
Reni Lestari ◽  
Kartika Ning Tyas ◽  
Arief N. Rachmadiyanto ◽  
Mahat Magandhi ◽  
Enggal Primananda ◽  
...  

Abstract Sorghum (Sorghum bicolor (L.) Moench) is a potential plant for food, livestock feed, biofuel, sugar, alcohol, and other bioindustry products. Sorghum could be adaptable to grow and expand in marginal areas of the world. Varieties of sorghum have their specific morpho-agronomic characters. It would be significant to compare the performance of multiple sorghum varieties to identify a suitable one for the intended use. The increase in biomass plant production could be caused by cultivation factors, such as an increased planting density. This study aims to determine the response of four different sorghum varieties to the treatment of the plant density on the biomass, grain production, and sugar content of stem juice. This research was conducted using two factors: sorghum variety (“Super 1,” “Keler,” “Lepeng,” and “Rio”) and the plant density (two, four, and six plants per hole or 106,667; 213,333; and 320,000 plants ha−1, respectively). The results of the study showed that all four sorghum varieties tested could be used as biomass resources. The highest plant dry biomass was gained from six plants per hole with 44.0 t ha–1, whereas the lowest one was two plants per hole with 30.4 t ha–1. “Super 1” was a superior variety due to the significant highest sugar content of the stem juice (13.9°Brix) and grain production. “Lepeng” variety was the lowest in both sugar content (8°Brix) and grain production, whereas “Keler” and “Rio” varieties contained sugar in between 8.5 and 10.8°Brix of the stem juice.


HortScience ◽  
2021 ◽  
Vol 56 (2) ◽  
pp. 286-290
Author(s):  
Ravneet K. Sandhu ◽  
Nathan S. Boyd ◽  
Lincoln Zotarelli ◽  
Shinsuke Agehara ◽  
Natalia Peres

Florida vegetable growers are facing high production costs due to high input costs, lower profitability, and competition from foreign markets. Multi/intercropping allows growers to increase the yields and profits per unit area by producing multiple crops on the same beds. Experiments determining the effects of intercropping and plant spacing was conducted in Fall 2018 and 2019 at Gulf Coast Research and Education Center, Balm. Tomato and bell pepper were intercropped at low and high planting density on plastic-covered beds. Bell pepper shoot biomass was significantly (P < 0.001) reduced when intercropped with tomato, compared with monocropped bell pepper. However, tomato shoot biomass was significantly reduced when tomato plant density increased, but it was unaffected by bell pepper intercropping. Biomass of both crops was unaffected by relay cropping. Bell pepper yields when intercropped with tomato at low density (60 cm tomato-tomato and 38 cm pepper-pepper) had similar yields to bell pepper planted alone in low and high planting density. We concluded that bell pepper plants were more sensitive to interspecific competition, whereas tomato plants were more sensitive to intraspecific competition. Intercropping may be a viable option for growers at recommended plant densities used for monocrops. However, high plant density is not recommended.


2000 ◽  
Vol 36 (3) ◽  
pp. 379-395 ◽  
Author(s):  
P. Q. CRAUFURD

Three alternate-row intercrop experiments of sorghum (Sorghum bicolor)–cowpea (Vigna unguiculata) and/or millet (Pennisetum glaucum)–cowpea were grown at plant densities of 20 000 to 80 000 plants ha−1 at two locations in northern Nigeria between 1990 and 1992 to examine relations between yield and plant density. These relations were examined using the reciprocals of yield per plant to determine effects of environment, species and genotype on the theoretical maximum yield and optimum plant density. The intercrops were dominated by cereals, and cowpea biomass (BY) and seed yield (SY) were <10% of cereal BY and SY. Cowpea yields decreased as cereal plant density (D) increased, whereas cereal and total intercrop yields increased asymptotically with increasing D. Biomass yield of all intercrops responded to increasing D in a similar manner and the theoretical maximum intercrop BY was 12 290 kg ha−1 in all experiments. The response of SY to D varied among intercrops and was greatest and least with early and late maturing cereals respectively. The optimum D required to produce 90% maximum intercrop BY and SY varied between 15 600 and 30 000 plants ha−1, and 0 (no response to D) and 120 000 plants ha−1 respectively, and was higher for sorghum than for millet intercrops. The implications of these responses for agronomic management and germplasm improvement of cereal–cowpea intercrops are discussed.


1973 ◽  
Vol 81 (3) ◽  
pp. 455-463 ◽  
Author(s):  
E. S. Bunting

SUMMARYResults from 10 field experiments are reported. Inra 200, the standard variety in official maize grain trials in Britain, was grown in six of the trials; comparative information was obtained on a range of competitive commercial hybrids and an experimental, early flowering, hybrid. The final plant densities most commonly involved ranged from 5 to 20 plants/m2, with extremes of 2 and 30 plants/m2. The effects of spatial arrangement were also considered in multifactorial or systematic designs; in general, yields increased slightly with more even spacing but no evidence was adduced that spacing, within the limits likely to be encountered in commercial practice, would significantly modify interpretations of density effects.In all varieties tested, a satisfactory model for the response in yield of grain to changes in plant density was 1/y = a + bx + cx2, where y = grain yield/plant and x = density. Estimated parameter values, however, were not the same for all varieties and significant genotype × density interactions were obtained.Grain yield/unit area in Inra 200 was maximal at densities of 8–10 plants/m2, but the response curve did not have a pronounced peak; differences in average yieldat densities ranging from 6 to 14 plants/m2 were less than 6%, and yield at 20 plants/m2 was about 80% of the maximum. Other flint × dent hybrids grown commercially for grain in northern areas (Anjou 210, L.G. 11, Warwick SL 209) reached maximum grain yield/unit area at lower densities (6–8 plants/m2), and the decline in yield with increasing density was much more marked than in Inra 200. In contrast, an earlier flowering, shorter growing, experimental hybrid (ARC 51 A) did not reach maximum yield until density was raised to 14 plants/m2, and was even more tolerant of high plant densities than Inra 200. With increasing plant density the number of ears/plant declined, falling below 1–0 in Inra 200 at densities in excess of 10 plants/m2, and averaging about 0–8 at plants/m2. Over the range 6–20 plants/m2 shelling percentage was reduced by no more than 4%, but water content of the ear (grain plus rachis) increased significantly with density. In the very early hybrid, ARC 51A, the difference in water content of the ear at 6 and 20 plants/m2 was less than 3%, but in Inra 200 it averaged about 8% and in varieties less tolerant of high densities it was often ofthe order of 15%. These results could be related to the delaying effects of increasing density on time of silk emergence. Relatively, time of pollen shed was little affected by density changes. In Inra 200 the difference in time between mid-anthesis and mid-silk was about 7 days more at 20 plants/m2 than at 6 plants/m2 while in Anjou 210 and Kelvedon 59A the comparable increase was 14 days.The practical significance of the findings is discussed in relation to current grain and silage maize production practices, and to future breeding and testing programmes in Northern Europe.


2021 ◽  
Vol 911 (1) ◽  
pp. 012046
Author(s):  
Suwardi ◽  
Syafruddin ◽  
Muhammad Aqil ◽  
Roy Efendi ◽  
Z. Bunyamin

Abstract One of the strategies to increase maize production is by selecting the proper combination among variety and planting density. The plant density population experiment was carried out to identify the candidate of maize variety that has high productivity with limited sunlight levels. Our hypothesis was how the erect leaf maize type can get optimal sunlight and affect the productivity. The study was conducted in IP2TP Bajeng, Gowa, South Sulawesi from March to June 2020. This study was designed under split plot design where spacing or plant density as the main plot with 3 levels of treatment (70 cm x 20 cm (population 71,428 plants/ha), 60 cm x 20 cm (population 83,333 plants/ha) and 50 cm x 20 cm (population 100,000 plants/ha). Furthermore, eight genotypes of hybrid maize (ERC 01, ERC 02, ERC 03, ERC 04, ERC 05, ERC 06, ERC 07, ERC 08), including control varieties (JH 45 and Pioneer 36) were treated as the sub-plots. The results indicated that the maize yield increase in line with the increase in plant population. The plant’s spacing of 70 x 20 cm with 100,000 plants/ha was produced 10.61 t/ha, significantly higher than other treatments.


1969 ◽  
Vol 68 (3) ◽  
pp. 243-252
Author(s):  
J. E. Asiegbu ◽  
J. O. Uzo

Results indicated the need for use of organic manures even when a high rate of NPK fertilizer was applied. Farmyard manure (FYM) benefitted fruit set in egg plant and generally enhanced size characters in both onion and eggplants. FYM helped to increase the proportion of grade one onions, especially at relatively high plant densities. Increasing plant density increased yield per hectare, but decreased productivity per plant. Yield increase per hectare was therefore largely dependent on number of plants contributing to yield and, in eggplant, also on the number of fruits set per plant.


HortScience ◽  
1998 ◽  
Vol 33 (5) ◽  
pp. 816-818 ◽  
Author(s):  
Haim Nerson

Two field experiments were conducted in Bet Hashita (1992) and Newe Ya'ar (1993), Israel, in order to examine the possibility of using plant growth habit, chlorflurenol, and plant population density to concentrate yield of pickling cucumber (Cucumis sativus L.) under a simulated once-over mechanical harvest system. Two near-isogenic cucumber lines, WI 1983G normal and WI 1983G little leaf, were grown under three plant densities, 5, 10, and 20 plants/m2, and at flowering half of the plants were treated with 50 mg·L-1 chlorflurenol solution. The little leaf line produced a smaller canopy than the normal line under five plants/m2 but a larger canopy under 20 plants/m2. The average commercial yield of the little leaf line was higher than that of the normal leaf line by 28% and 55% in Bet Hashita and in Newe Ya'ar, respectively. The highest yield of each line was achieved under the highest plant density. The average commercial yields under 20 plants/m2 were 1.13 and 0.91 kg·m-2 in Bet Hashita and 1.86 and 0.92 kg·m-2 in Newe Ya'ar for little leaf and normal leaf, respectively. Chlorflurenol increased fruit number per unit area but did not increase yield. Nevertheless, it increased the proportion of small fruits, which are more valuable. The present study shows that the little leaf growth habit can increase the yield concentration in pickling cucumber and make this crop more suitable for a once-over mechanical harvest. Chemical name used: methyl-2-chloro-9-hydroxyfluorene-9-carboxylate (chlorflurenol).


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