Plant Population Management

1994 ◽  
pp. 61-83
Author(s):  
David R. Given
Keyword(s):  
Population Management ◽  
Plant Population

PENGARUH POPULASI TANAMAN DAN PENGGUNAAN MULSA TERHADAP POPULASI GULMA DAN HASIL PUCIL JAGUNG MANIS (ZEA MAYS SACCHARATA STURT) DI LAHAN KERING

AGRICA ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 124-133
Author(s):  
I Ketut Arsa Wijaya
Keyword(s):  
Zea Mays ◽  
Block Design ◽  
Plant Population ◽  
Cyperus Rotundus ◽  
Corn Kernel ◽  
Plastic Mulch ◽  
Rice Plants ◽  
Straw Mulch ◽  
Combination Treatments ◽  
Randomized Block Design

This study was conducted in Balai Benih Induk (BBI) Luwus, Baturiti District, Tabanan Regency, with the high of place 506m above sea level occurring in March to May 2014. This research used randomized block design arranged per factor, namely population of plants (P) including three steps: P1=80.000 plants per hectare, P2= 100.00 plants per hectare, P3= 120.000 per hectare; and mulch (M) that include: M0= without mulch and without cleaning, M1= without mulch with clean weeding, M2= rice plants straw mulch (5 ton per hectare) and M3= black silver plastic mulch. Eventually, there were 12 combination treatments, each of which was repeated 3 times to obtain 36 land slots. The research indicates that there was no real interaction between the treatment of plant population and mulch usage in all variables observed. The 100.000 plant population per hectare can produce the weight of dry and fresh oven corn kernel without highest cornhusk that was to say 4.79 tons and 0.53 tons or 11.66 % and 20.45% higher compared to 120.000 plant population per hectare. The use of black silver plastic and rice plants straw mulch can produce the weight of fresh and dry oven corn kernel without cornhusk per hectare each of which is 4.69 tons, 4.57 tons, and 0.54 tons, 0.47 tons or 26.76%, 38.46 %, and 23.51 %, 20.51 % higher than without mulch and without clean weeding. Clean weeding treatment can produce the weight of fresh and dry oven corn kernel without cornhusk per hectare with its weight of 4.63 tons and 0.51 tons or 25.35 % and 35.90 % higher than without mulch and cleaning. Clean weeding treatment was not obviously different from mulch treatment. The identification of weed types were 19 kinds of weeds and Cyperus rotundus L. Weeds. They have the highest density and each absolute frequent of 1249.333 stems m-2 and 1.00.

scholarly journals Limited Dispersal, Deleterious Mutations and the Evolution of Sex

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1053-1060
Author(s):  
Joel R Peck
Keyword(s):  
Mathematical Model ◽  
Sexual Reproduction ◽  
Genetic Locus ◽  
Genetic Material ◽  
Plant Population ◽  
Deleterious Mutations ◽  
Animal Populations ◽  
Offspring Sex ◽  
Limited Dispersal ◽  
Hermaphroditic Plant

Abstract This study presents a mathematical model that allows for some offspring to be dispersed at random, while others stay close to their mothers. A single genetic locus is assumed to control fertility, and this locus is subject to the occurrence of deleterious mutations. It is shown that, at equilibrium, the frequency of deleterious mutations in the population is inversely related to the rate of dispersal. This is because dispersal of offspring leads to enhanced competition among adults. The results also show that sexual reproduction can lead to a decrease in the equilibrium frequency of deleterious mutations. The reason for this relationship is that sex involves the dispersal of genetic material, and thus, like the dispersal of offspring, sex enhances competition among adults. The model is described using the example of a hermaphroditic plant population. However, the results should apply to animal populations as well.

scholarly journals Variable-rate in corn sowing for maximizing grain yield

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eder Eujácio da Silva ◽  
Fábio Henrique Rojo Baio ◽  
Daniel Fernando Kolling ◽  
Renato Schneider Júnior ◽  
Alex Rogers Aguiar Zanin ◽  
...  
Keyword(s):  
Grain Yield ◽  
Vegetative Growth ◽  
Maximum Yield ◽  
Influential Factors ◽  
Plant Population ◽  
Seeding Density ◽  
Corn Yield ◽  
Growth Indices ◽  
Experimental Conditions ◽  
Soil Attributes

AbstractSowing density is one of the most influential factors affecting corn yield. Here, we tested the hypothesis that, according to soil attributes, maximum corn productivity can be attained by varying the seed population. Specifically, our objectives were to identify the soil attributes that affect grain yield, in order to generate a model to define the optimum sowing rate as a function of the attributes identified, and determine which vegetative growth indices can be used to predict yield most accurately. The experiment was conducted in Chapadão do Céu-GO in 2018 and 2019 at two different locations. Corn was sown as the second crop after the soybean harvest. The hybrids used were AG 8700 PRO3 and FS 401 PW, which have similar characteristics and an average 135-day cropping cycle. Tested sowing rates were 50, 55, 60, and 65 thousand seeds ha−1. Soil attributes evaluated included pH, calcium, magnesium, phosphorus, potassium, organic matter, clay content, cation exchange capacity, and base saturation. Additionally, we measured the correlation between the different vegetative growth indices and yield. Linear correlations were obtained through Pearson’s correlation network, followed by path analysis for the selection of cause and effect variables, which formed the decision trees to estimate yield and seeding density. Magnesium and apparent electrical conductivity (ECa) were the most important soil attributes for determining sowing density. Thus, the plant population should be 56,000 plants ha−1 to attain maximum yield at ECa values > 7.44 mS m−1. In addition, the plant population should be 64,800 plants ha−1 at values < 7.44 mS m−1 when magnesium levels are greater than 0.13 g kg−1, and 57,210 plants ha−1 when magnesium content is lower. Trial validation showed that the decision tree effectively predicted optimum plant population under the local experimental conditions, where yield did not significantly differ among populations.

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