scholarly journals Spacing experiments with brussels sprouts grown for single-pick harvests.

1970 ◽  
Vol 18 (1) ◽  
pp. 89-104
Author(s):  
E.W.M. Verheij

Two-year trials are discussed on the effects of different spacings, planting pattern and row orientation, stopping the plants, and time of harvest on the cropping, habit and root growth of the hybrid brussels sprouts variety Thor. Yields of dry matter per sq.m. rose sharply with increasing plant density up to about 4 plants per sq.m., above which there was little further increase. The average weight per plant, however, showed the reverse trend, and declined with closer spacing. The total yields of sprouts from unstopped plants attained a maximum at a density of about 1 plant per sq.m., but the maximum yields and numbers of marketable sprouts were obtained with densities of about 2 and 2 plants per sq.m., respectively. Plants grown at high densities were taller and more slender than low-density plants, a habit well suited to mechanical stripping. Moreover, the sprouts from high-density plants were more uniform, which facilitated grading. There was little difference between the number and distribution of the roots, including depth of rooting, over a wide range of plant densities. However, high-density plants had fewer thick roots, and at the widest spacings the total number of roots per sq.m. declined. The pattern of planting had a slight influence on the height of the low-density plants, but differential effects of various row orientations were negligible. Stopping the plants greatly increased the total yields of sprouts at all densities; the numbers of marketable sprouts from the stopped plants were also greater, especially at densities of 3 plants per sq.m. and above. Harvesting stopped plants in late October instead of late September resulted in much higher yields of sprouts at all densities except the lowest, despite a decline in the fresh weights of the plants during this period.-I.T.T., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

2019 ◽  
Vol 4 (3) ◽  

The present study was undertaken with a view to study the effect of plant density on yield and yield attributes of two soybean varieties in kharif–II season. The experiment was conducted in kharif-II season 2012 at mymensingh with two soybean varieties, namely PB-1 (Shohag) and G-2 (Bangladesh soybean-4) and six plant densities, viz; 20, 40, 60, 80, 100 and 120 plants m-2 established using an equidistant (square) planting pattern of 22.4cm x 22.4 cm, 15.8 cm x 15.8 cm, 12.9 cm x12.9 cm, 11.2 cm x 11.2 cm, 10 cm x 10 cm and 9.1 cm 9.1 cm, respectively. The experiment was laid out in a split-plot design with varieties in main-plots and plant densities in sub-plots. The treatments were replicated three times. Increased plant density increased plant height, number of nodes plant-1, total dry matter, seed yield (1.02 t ha-1) and Stover yield (1.15 t ha-1) 80 to 100 plants m-2 and then decreased with increased plant density. Again increased plant density linearly decreased in number of branches plant-1, fertile pods plant-1, non-fertile pods plant-1, number of seeds plant-1, seed yield plant-1 and 100- seed weight up to 120 plants m-2 depending on variety and season. The study concludes that the highest yield of soybean in kharif –II season could be obtained from varietyPB-1 with a plant density of 100 plants m-2 and 80 plants m-2in G-2.


1980 ◽  
Vol 16 (3) ◽  
pp. 321-326 ◽  
Author(s):  
G. O. Iremiren ◽  
G. M. Milbourn

SUMMARYIncreasing plant density in maize from 8 to 32 plants/m2, without irrigation, had little effect on the time of ear primordia differentiation but delayed the time of silking (by up to 16 days), reduced the potential grain sites available for pollination and the number of grains pollinated, and increased grain abortion during the grain fill period. In cv LG11 sufficient fertile ears were retained to maintain grain yield throughout the wide range in density, whereas yield fell in Anjou 210 due to barrenness after silking, which was the major factor responsible for the intolerance of this variety to high density. However, in a variety such as Anjou 210, which has a tendency to barrenness under stress, the grain content of the end product would not be affected at the plant densities normally used for maize silage.


2017 ◽  
Vol 30 (3) ◽  
pp. 670-678 ◽  
Author(s):  
ROGÉRIO PERES SORATTO ◽  
TIAGO ARANDA CATUCHI ◽  
EMERSON DE FREITAS CORDOVA DE SOUZA ◽  
JADER LUIS NANTES GARCIA

ABSTRACT The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.


1978 ◽  
Vol 26 (4) ◽  
pp. 383-398 ◽  
Author(s):  
A. Darwinkel

The effect of plant density on the growth and productivity of the various ear-bearing stems of winter wheat was studied in detail to obtain information on the pattern of grain production of crops grown under field conditions. Strong compensation effects were measured: a 160-fold increase in plant density (5-800 plants/m2) finally resulted in a 3-fold increase in grain yield (282 to 850 g DM/m2). Max. grain yield was achieved at 100 plants/m2, which corresponded to 430 ears/m2 and to about 19 000 grains/m2. At higher plant densities more ears and more grains were produced, but grain yield remained constant. Tillering/plant was largely favoured by low plant densities because these allowed tiller formation to continue for a longer period and a greater proportion of tillers produced ears. However, at higher plant densities more tillers/unit area were formed and, despite a higher mortality, more ears were produced. The productivity of individual ears, from main stems as well as from tillers, decreased with increasing plant density and with later emergence of shoots. In the range from 5 to 800 plants/m2 grain yield/ear decreased from 2.40 to 1.14 g DM. At 800 plants/m2 nearly all ears originated from main stems, but with decreasing plant density tillers contributed increasingly to the number of ears. At 5 plants/m2, there were 23 ears/plant and grain yield/ear ranged from 4.20 (main stem) to 1.86 g DM (late-formed stems). Grain number/ear was reduced at higher densities and on younger stems, because there were fewer fertile spikelets and fewer grains in these spikelets. At the low density of 5 plants/m2, plants developed solitarily and grain yield/ear was determined by the number of grains/ear as well as by grain wt. Above 400 ears/m2, in this experiment reached at 100 plants/m2 and more, grain yield/ear depended solely on grain number, because the wt. of grains of the various stems were similar. The harvest index showed a max. of about 44% at a moderate plant density; at this density nearly max. grain yield was achieved. At low plant densities the harvest index decreased from 45% in main stems to about 36% in late-formed stems. However, no differences in harvest index existed between the various ear-bearing stems if the number of ears exceeded 400/m2. (Abstract retrieved from CAB Abstracts by CABI’s permission)


Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5273
Author(s):  
Luis Carlos Sandoval-Herazo ◽  
Alejandro Alvarado-Lassman ◽  
María Cristina López-Méndez ◽  
Albino Martínez-Sibaja ◽  
Alberto A. Aguilar-Lasserre ◽  
...  

Wastewater treatment (WWT) is a priority around the world; conventional treatments are not widely used in rural areas owing to the high operating and maintenance costs. In Mexico, for instance, only 40% of wastewater is treated. One sustainable option for WWT is through the use of constructed wetlands (CWs) technology, which may remove pollutants using cells filled with porous material and vegetation that works as a natural filter. Knowing the optimal material and density of plants used per square meter in CWs would allow improving their WWT effect. In this study, the effect of material media (plastic/mineral) and plant density on the removal of organic/inorganic pollutants was evaluated. Low (three plants), medium (six plants) and high (nine plants) densities were compared in a surface area of 0.3 m2 of ornamental plants (Alpinia purpurata, Canna hybrids and Hedychium coronarium) used in polycultures at the mesocosm level of household wetlands, planted on the two different substrates. Regarding the removal of contaminants, no significant differences were found between substrates (p ≥ 0.05), indicating the use of plastic residues (reusable) is an economical option compared to typical mineral materials. However, differences (p = 0.001) in removal of pollutants were found between different plant densities. For both substrates, the high density planted CWs were able to remove COD in a range of 86–90%, PO4-P 22–33%, NH4-N in 84–90%, NO3-N 25–28% and NO2-N 38–42%. At medium density, removals of 79–81%, 26–32, 80–82%, 24–26%, and 39–41%, were observed, whereas in CWs with low density, the detected removals were 65–68%, 20–26%, 79–80%, 24–26% and 31–40%, respectively. These results revealed that higher COD and ammonia were removed at high plant density than at medium or low densities. Other pollutants were removed similarly in all plant densities (22–42%), indicating the necessity of hybrid CWs to increase the elimination of PO4-P, NO3-N and NO2-N. Moreover, high density favored 10 to 20% more the removal of pollutants than other plant densities. In addition, in cells with high density of plants and smaller planting distance, the development of new plant shoots was limited. Thus, it is suggested that the appropriate distance for this type of polyculture plants should be from 40 to 50 cm in expansion to real-scale systems in order to take advantage of the harvesting of species in these and allow species of greater foliage, favoring its growth and new shoots with the appropriate distance to compensate, in the short time, the removal of nutrients.


1999 ◽  
Vol 132 (2) ◽  
pp. 173-180 ◽  
Author(s):  
J. E. LEACH ◽  
H. J. STEVENSON ◽  
A. J. RAINBOW ◽  
L. A. MULLEN

The effects of plant density on the growth and yield of winter oilseed rape (Brassica napus) were examined in a series of five multifactorial experiments at Rothamsted Experimental Station between 1984 and 1989. Plant densities, manipulated by changing the seed rate and row spacing, or because of overwinter losses, ranged from 13·5 to 372 plants/m2. Normalized yields for the multifactorial plots increased with densities up to 50–60 plants/m2. In very high density plots in 1987/88, yield decreased as density increased >150 plants/m2. Plants grown at high density had fewer pod-bearing branches per plant but produced more branches/m2. Branch dry matter (DM) per plant was decreased by 42%, the number of fertile pods per plant and pod DM/plant by 37%. There was no effect of density on the number or DM of pods/m2. Over 74% of the fertile pods were carried on the terminal and uppermost branches of plants grown at high density in 1987/88 compared with only 34% in plants grown at low density in 1988/89. Seed DM/plant decreased with increase in density but seed size (1000-seed weight) increased. There was no effect of density on seed glucosinolate or oil contents.


1988 ◽  
Vol 28 (3) ◽  
pp. 377 ◽  
Author(s):  
GJ Leach ◽  
DF Beech

Interception of radiation by chickpea (Cicer arietinum L.), in a year of below-average rainfall, and water use in both wet and dry years, were studied on a deep vertisol soil at Dalby, south-eastern Queensland. Measurements were made on 4 accessions (cv. Tyson, K223, CPI 56287 and CPI 56289) grown at a number of row spacings. Canopies intercepted less than 20% of incident radiation during the first 70 days after sowing (DAS) in the dry year (1980) before radiation interception reached a peak in mid-September (100 DAS) at about 70% interception in 250 mm rows. Above-ground dry matter was linearly related to intercepted radiation to the end of September (119 DAS), giving an efficiency of radiation conversion of 1.4 g DM per MJ of intercepted photosynthetically active radiation. Efficiency of conversion was marginally higher with 125 mm than with 62.5 mm intra-row spacing in rows 250 mm apart. In a wet year (1979), chickpea extracted water from below 1 m depth in the soil profile and used 356 mm water. In the dry year, only 16 1 mm water was used and none was extracted from below 1 m. K223 used water faster than cv. Tyson, and extraction was faster with close than with wide row spacing. Above-ground dry matter was produced at an efficiency of 3.4 (1980) to 4.2 (1979) g m-2 mm-I of water during the main period of growth through September, and a mean of 0.7 g m-2 seed for 2 seasons was produced per mm of water used over the whole season. The small differences in water extraction between accessions and spacing treatments were reflected during pod-filling as differences in plant water potential of 0.1-0.2 MPa during the early afternoon stress period. Chickpea appears to have poor stomata1 control over water loss, being comparable to summer legumes like soybean rather than to cowpea. We conclude that the benefit of close row spacing in enhancing radiation interception outweighs the small disadvantage from accelerated water depletion. The ability of chickpea to produce useful seed yields over a wide range of soil water availability makes it well suited for opportunistic winter cropping.


2019 ◽  
Vol 157 (1) ◽  
pp. 63-71
Author(s):  
A. C. Vieira ◽  
C. J. Olivo ◽  
C. B. Adams ◽  
J. C. Sauthier ◽  
L. R. Proença ◽  
...  

AbstractThe effects of growing pinto peanut mixed with elephant grass-based pastures are still little known. The aim of the current research was to evaluate the performance of herbage yield, nutritive value of forage and animal responses to levels of pinto peanut forage mass mixed with elephant grass in low-input systems. Three grazing systems were evaluated: (i) elephant grass-based (control); (ii) pinto peanut, low-density forage yield (63 g/kg of dry matter – DM) + elephant grass; and (iii) pinto peanut, high-density dry matter forage yield (206 g/kg DM) + elephant grass. The experimental design was completely randomized with the three treatments (grazing systems) and three replicates (paddocks) in split-plot grazing cycles. Forage samples were collected to evaluate the pasture and animal responses. Leaf blades of elephant grass and the other companion grasses of pinto peanut were collected to analyse the crude protein, in vitro digestible organic matter and total digestible nutrients. The pinto peanut, high-density dry matter forage yield + elephant grass treatment was found to give the best results in terms of herbage yield, forage intake and stocking rate, as well as having higher crude protein contents for both elephant grass and the other grasses, followed by pinto peanut with low-density forage yield + elephant grass and finally elephant grass alone. Better results were found with the grass–legume system for pasture and animal responses.


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.


1982 ◽  
Vol 62 (4) ◽  
pp. 1143-1148 ◽  
Author(s):  
L. J. FISHER ◽  
N. A. FAIREY

A late-maturing corn hybrid, Funk brand G4444, was planted in 2-ha plots at 60 000 plants per hectare (low density) and at 100 000 plants per hectare (high density). At harvest, the dry matter and ear contents were 24.2 and 34%, respectively, for the low-density treatment and 22.8 and 28%, respectively, for the high-density treatment. Two groups of 10 lactating cows were used to compare the nutritive value of the ensiled forages over a 10-wk feeding period. Silage dry matter intake, milk yield and milk fat content were 10.33 kg/day, 27.11 kg/day and 3.52% for the cows fed high-density silage compared to 11.79 kg/day, 31.88 kg/day and 2.91% for those fed the low-density silage. Feeding the low-density silage resulted in a decreased level of acetic acid in the rumen and an increased level of propionic acid. Blood hematocrit and plasma calcium levels were lower for cows fed the silage from the low-density planting. Dry matter digestibility of the complete ration was 72.5 and 71.8% for the high- and low-density plantings, respectively. It was concluded that an increased ear content of approximately 10 percentage units resulted in a corn silage which was consumed more readily, altered rumen fermentation and caused a decrease in milk fat content. Key words: Corn silage, lactating dairy cows, planting density


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