Pots were then firmly tapped on the floor 4 times to settle the soil. In the spring and experiments, K was not found to be influenced by the experimental factors Tables 3. A study by Chambers and Holm using P32 to study the site of P uptake from soil by green foxtail Setaria viridis L. Soil fertility requirements for lettuce production on organic soils in Florida have been established Sanchez, Spiny amaranth densities of 1 and 4 plants per 2. Spiny amaranth density Duration of weed interferencea Low High P conc.

While K fertilizer can be applied as needed after the crop is planted, the entire amount of P to be used for a crop is applied before planting. In the spring of , 10 heads were taken from each side of the bed. Phosphorus application Experiment pH Pwa broadcast band Kg ha’ – spring 6. You are commenting using your Google account. Per plant dry weight data were analyzed using analysis of variance with a complete factorial treatment arrangement.

All components of the intended mixtures are of economic value to the grower.

These series can be established at each of several levels for the set density component of a series Vleeshouwers et al.

The purpose of these studies was to establish P fertility rates to be used in the competition studies. This is an example of how the term competition is commonly used to refer to the overall effect that weeds have on crop growth due to interactions between plants growing in close proximity to one another.

I also am greatly indebted to the faculty at the Everglades Research and Education Center at Belle Glade for valuable assistance and encouragement they provided me.

Literature review on amaranthus hybridus

For the duration of weed interference of hybriduz days, P concentrations in lettuce were lower under high than low weed density. This suggests that with broadcast fertilizer application lettuce may have been taking up more P than was required for the yields obtained in the experiments.


Some information concerning the effect weeds have on lettuce is found in studies in which herbicides and other control methods are evaluated Dusky et al. In order to address the question of the effect that density has on competitive relations, the method can be further expanded by conducting the replacement series at varied densities Jolliffe et al.

literature review on amaranthus hybridus

Greater than 90 percent of this production occurred on Everglades histosols. Phosphorus applied broadcast as an experimental treatment. However, there were no interactions between density and P fertility in the analysis of interspecific competition.

literature review on amaranthus hybridus

Lettuce Nutrient Analysis Concentrations of macronutrients in lettuce in the springfall and spring studies are given in Tables 3. Actual means and regressions of yield on durations of weed interference are shown. It is called keerai masial.

Fertilizer P for the banded treatments was applied during the bed formation process. Nevertheless, competition for both below and above ground factors appears to be important. Each experiment was conducted as a randomized complete block design with 3 replications.

Samples were thoroughly mixed following grinding and a subsample of the ground material was used for hybriidus. As plant growth progressed and pot weight differences became evident, container weight differences due to differential moisture loss were compensated for by adding deionized water.

The interactions between the experimental factors for N concentrations did not appear to be meaningful.

Literature review on amaranthus hybridus – Don’t have time to do homework

In these studies with lettuce and spiny amaranth, however, essentially only the growth of lettuce was found to be influenced by P fertility. Increases in nutrient availability in competitive situations can be more detrimental than advantageous to the crop in some instances. During the final five weeks prior to harvest of the spring experiment there was considerable rainfall and substantially reduced solar radiation hjbridus two periods of several days.


Crop mineral nutrition is important in the production of quality lettuce Ryder, Duration of weed interference also had a significant effect on yield of untrimmed lettuce Table 3. Amaranths are recorded as food plants for some Lepidoptera butterfly and moth species including the nutmeg moth and various case-bearer moths of the genus Coleophora: As P concentration in lettuce tissue increased from 0.

The crop responds to each of P and K amendment in a predictable manner on these soils Sanchez and Burdine, In the spring study PA interacted with weed density Table 3. Soil fertility requirements for lettuce production on organic soils in Florida have been established Sanchez, On a longer term, competition is an important force influencing the higher plant composition of the ecosystem Grime, The study also suggested that proper timing of fertilization, in conjunction with weed control, can be valuable in enhancing the ability of the crop to suppress weeds that survive control measures.

Spiny amaranth densities of 1 and 4 plants per 2. In the spring experiment Ca concentrations showed a negative response to P application but did not differ for the two P application methods Table 3.

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