Dataset of allelopathic effects of Casuarina equisetifolia-L leaf aquatic extract on seed germination and growth of selected plant crops

In agricultural fields that are surrounded by dunes, the Casuarina tree is usually used as windbreaks. In addition, it plays a significant role in inhibiting nearby vegetation growth. In this dataset, the effect of Casuarina equisetifolia-L leaf aquatic extract on seed germination and growth of four selected plant crops (Maize, Lentil, Mustard, and Wheat) was tested. Seed germination test and a greenhouse experiment were conducted to study the effects of Casuarina equisetifolia aquatic leaf extract on seed germination and seedling growth. Various concentrations of leaf extract were used (0, 1.25%, 2.5%, and 5%). Results revealed that aqueous leaf extract of Casuarina equisetifolia-L affected significantly seed germination of all selected plant crops under laboratory conditions. Both wheat and maize have a comparable reduction in root length at 2.47 cm and 2.45 cm, respectively, but show a remarkable difference in percentage at 92% and 54% respectively under the effect of 5% aqueous solution. Similarly, lentil shows the highest drop in shoot length (SL) of 69% while no significant reduction observed in Mustard (SL) at the same aqueous solution concentration (5%). In the greenhouse experiment, dried leaf powder was mixed with soil in different concentrations (0, 15, 30, and 45 g kg−1 soil). Greenhouse experiments demonstrated that C. equisetifolia exhibited significant inhibition on wheat germination and seedling characteristics under all treatments. However, soil pH and electrical conductivity (EC) were examined and showed a relative reduction in pH and marked an increase in (EC).


a b s t r a c t
In agricultural fields that are surrounded by dunes, the Casuarina tree is usually used as windbreaks. In addition, it plays a significant role in inhibiting nearby vegetation growth. In this dataset, the effect of Casuarina equisetifolia-L leaf aquatic extract on seed germination and growth of four selected plant crops (Maize, Lentil, Mustard, and Wheat) was tested. Seed germination test and a greenhouse experiment were conducted to study the effects of Casuarina equisetifolia aquatic leaf extract on seed germination and seedling growth. Various concentrations of leaf extract were used (0, 1.25%, 2.5%, and 5%). Results revealed that aqueous leaf extract of Casuarina equisetifolia-L affected significantly seed germination of all selected plant crops under laboratory conditions. Both wheat and maize have a comparable reduction in root length at 2.47 cm and 2.45 cm, respectively, but show a remarkable difference in percentage at 92% and 54% respectively under the effect of 5% aqueous solution. Similarly, lentil shows the highest drop in shoot length (SL) of 69% while no significant reduction observed in Mustard (SL) at the same aqueous solution concentration (5%). In the greenhouse experiment, dried leaf powder was mixed with soil in different concentrations (0, 15, 30, and 45 g kg À1 soil). Greenhouse experiments demonstrated that C. equisetifolia exhibited significant inhibition on wheat germination and seedling characteristics under all treatments. However, soil pH and electrical conductivity (EC) were examined and showed a relative reduction in pH and marked an increase in (EC

Data
Allelopathy refers to the valuable or damaging effects of a specific plant on another, both crop and weed species, by the release of chemicals from plant parts [1]. Phenolics, terpenoids, and organic cyanides were reported as active allelochemicals can be leaching from leaves and stem of Casuarina trees and many plants to the environment [2e4]. The current data focused on the potential effects of Casuarina equisetifolia-L on Maize, lentil, Mustard, and Wheat crops during the study.
An experiment was conducted to measure the germination percentage, seedling inhibition, root and shoot length under the effect of the allelochemical compounds released from Casuarina equisetifolia leaves on Maize, Lentil, Mustard, and Wheat crops using Petri dishes under controlled lab conditions. Specifications Table   Subject Agricultural, chemical science Specific subject area Allelopathic effect of Casuarina equisetifolia leaf on seed germination Type of data Value of the Data Understanding the allelopathic effects of Casuarina equisetifolia-L on some plant crops (Maize, lentil, Mustard, and Wheat) germination percentage and seedling inhibition, root and shoot length. The present dataset could be useful for concerned researchers and those who interested in cultivation, from the potential effects of crops surrounded by Casuarina trees in order to select the candidate most suitable plant. Furthermore, the dataset introduced in this article can be used to investigate the possible effect of the chemicals released from Casuarina equisetifolia leaves on the potential of hydrogen (pH) and Electrical Conductivity (EC) of the soil.
The second experiment was performed using pots in the greenhouse, to study the actual effect of the fallen Casuarina equisetifolia leaves on the wheat crop germination and seedling in the presence of Mustard as a weed. Furthermore, the effect of soil mixed with Casuarina equisetifolia-L powder on (pH), and Electrical Conductivity (EC) were studied.

Petri-dish experiment
An aqueous leaf extract solution of Casuarina equisetifolia-L was added to each Petri dish to study the potential inhibition effects of germination in all crops selected. Significant effects on seeds germination were observed in the laboratory. Seedling growth results from the current study showed that the germination percentage, shoot, and root length of lentil, wheat, mustard, and maize were markedly suppressed by increasing the leaf aqueous extract concentration. (Tables 1 and 2).

Descriptive data
One-way ANOVA test was done to check the growth variation between four different treatments (0, 1.25, 2.5, and 5%) in the laboratory. A significant variation in (GP) was observed between the treatments in Lentil, Mustard, and Maize while in Wheat no significant difference found (Table 3).
Shoot and root length variations were tested under the same treatments and conditions. Germination percentage (GP), Standard Deviation (SD), root length (RL), shoot length (SL).  Significant variation was recorded between treatments in all seeds except Mustard shoot length (p > 0.05) at a confidence interval of 95% (Table 3).
The mean values of germination% (GP), shoot length (SL), and root length (RL) (with a standard deviation) for the studied crops were illustrated in Fig. 1

Greenhouse experiment
Greenhouse experiments were conducted to investigate the potential effect of Casuarina equisetifolia leaves on seedling growth of Wheat as a crop and Mustard as a weed with four treatments (control, 15, 30, 45 g/kg soil).
The seedling measurements of (GP, SL, and RL) were recorded weekly in three weeks. The results concluded that the growth of Wheat and Mustard plants, as indicated by germination percentage (Tables 4 and 5), showed opposite outcomes with Wheat (Stimulatory effect); the most significant germination occurred at high concentration (45 g kg À1 ) (Fig. 2).   A significant variation of seed germination percentage, shoot, and root length of wheat and Mustard between treatments were found except the Mustard root length had no differences among means (p > 0,05) at 95% confidence interval (Table 6).
Two physical parameters (pH and EC) of soil were tested under the effect of Casuarina dry leaves that were mixed with soil in different concentrations (Table 7).
The mean of measured pH values of soil was decreased gradually with increasing the treatment concentration, while the mean of EC was on the contrary (Fig. 3).
ANOVA test represents a noted variation (p > 0.05) between treatments in both pH and EC parameters. (Table 8).

Experimental design, materials, and methods
The treatments were organized in a completely randomized design (CRD) with four replicates in each set. In the Petri dish experiment, each single petri dish was considered as a replicate. Moreover, in the greenhouse experiment, each pot is considered one replicate Table 7 Means of pH, the electrical conductivity of soil, and their standard deviations as influenced by different concentrations of Casuarina leaf extracts of wheat and Mustard experiment in a greenhouse.   a Indicates significant differences among means at 0.05. The potential of Hydrogen (pH) and Electrical conductivity (EC).

Preparation of aqueous extract of Casuarina equisetifolia-L
Fresh leaves of Casuarina equisetifolia were collected from the area surrounding the College of Arts and Sciences, Qatar University. Leaves from mature trees were brought to the laboratory and were airdried in the oven at 50 C for 48 hours (Fig. 4). Then, the dried leaves were chopped into small pieces and ground into a fine powder. Distilled water was used to make plant extraction. Approximately 5 g of dried leaves powder was soaked into 50 ml distilled water followed by vigorous shaking for 48 hours at room temperature. The resulting solution was centrifuged, and the supernatant was filtered using a vacuum filter unit 1000 ml (Buchner Apparatus) to obtain a stock solution. The resulting brownish and dark extract was stored in the fridge in conical flasks until required.
Sequential dilutions were applied to the prepared stock solution to obtain three different concentrations (1.25%, 2.50%, and 5.00%) using Equation (1) (Table 9), with distilled water used as a control treatment (Fig. 5).
where. DF% is a final concentration percentage after dilution.

Germination test
Seeds of four crop plants (Maize, lentil, Mustard, and Wheat) were used in the seed germination test. Healthy uniform size seeds were selected and washed thoroughly four times by distilled water to remove any chemical residues and well dried using tissue paper. 10e20 seeds of each species were placed evenly (based on seed size) in sterilized 9 cm Petri dishes lined with a double layer of Whatman filter papers. The experimental set includes four different concentration of aqueous extract 0% 1.25%, 2.50% and 5.00%. The treated Petri dishes with distilled water were taken as a control, and it was  considered as a zero concentration, while others were treated with approximately 8 ml of different aqueous extracts. Petri dishes were kept undisturbed under controlled lab conditions (room temperature (24 ± 2 C), light) on the laboratory bench until germination occurs. (Fig. 6).

Seed germination and seedling growth
Seeds are considered germinated upon radical emergence, germination is determined by counting the number of germinated seeds each two days interval over a 6e8 days period to observe the germination rate. After eight days, the germination percentage (GP) was determined by counting the number of seeds germinated during the period of the experiment over the total number of seeds based on Equation (2), [5].

GP ¼
Number of germinated seeds Total number of seeds Â 100 Where GP. Germination percentage. Shoot length and root length were measured using a centimeter ruler by taking five seedlings at random from each petri dish.

Greenhouse experiment
The experiment was performed in the greenhouse to investigate the effect of C. equisetifolia leaves on plant growth. Two different crop plants were selected to grow together in this experiment under C. equisetifolia leaf residuals with different dosages. Mustard is considered as a weed plant and competition  factor against wheat growth. Dried leaf powder of C. equisetifolia was mixed with peat moss and clay (1:4) at a rate of 15, 30, and 45 g kg À1 of soil, in addition to the control treatment with no leaf powder. Plastic pots of 15 cm in diameter were filled with 2 kg of soil. Ten viable seeds of wheat with fifteen seeds of Mustard were sown together in each pot. Water supplied as required to avoid water stress. Pots were arranged in a completely randomized block design with four replications (Fig. 7).

Data collection of the greenhouse experiment
Number of germinated seeds was observed weekly in three weeks, then germination percentage was calculated by counting the number of seeds germinated over the total number of seeds based on Equation (2), [5]. After plant maturity, data were recorded for growth parameters including the number of shoots, root lengths (cm), number of spikes, plant height, fresh and dry weights (g/plant), stem diameter (mm), as well as a number of leaves. In addition, soil physical analysis was conducted Electric conductivity EC and pH. In the end, statistical analysis was conducted to all the collected results using analysis of variance and means comparisons.