Effect of Alchornea cordifolia , Tithonia diversifolia and Mezoneuron benthamianum treatment time on agromorphological parameters of tomato in Daloa (Côte d’Ivoire)

— The cultivation of tomato (Solanum lycopersicon L.) is confronted with many production problems related to the strong parasite pressure and especially to the fertility of soils. Thus, the effectiveness of powdery extracts of three plants (Alchornea cordifolia, Tithonia diversifolia and Mezoneuron benthamianum) was evaluated on the tomato crop and their ability to improve agromrphological parameters. Quantities of 5 g and 15 g of these extracts were used to treat the cultivation soil one month, one week and the day of transplanting of tomato plants. The results showed that A. cordifolia, Tithonia diversifolia and Mezoneuron benthamianum significantly improved the growth parameters and development of the plants at the amounts of 5 g and 15 g, on. The efficacy of the extracts varied depending on the plant used, the concentrations and the period of soil treatment. These plant extracts have biostimulatory properties and can be used as renewable resources for healthy and sustainable agriculture.


INTRODUCTION
Tomato (Solanum lycopersicon) is one of the most important vegetable crops in the world (Naika et al., 2005). According to the Food and Agriculture Organization of the United Nations (FAO), it is the second most important vegetable crop after potatoes. It is cultivated in more than 170 countries of the world in various climates, including relatively cold regions thanks to the development of crops under cover (FAO, 2007). Global tomato production has grown significantly since 1978, when it increased from 48 million tons to over 180 million tons in 2017 (FAOSTAT, 2018). Tomato, is grown for its fleshy, highly sought after fruit, rich in phenolic antioxidants and then mineral elements such as lycopene, carotenoids, vitamins A, C and E (Daniel et al., 2012;Ignace et al., 2015). Tomato is one of the most important fruit vegetables in the human diet as it contributes to a healthy and balanced human diet that can be consumed fresh or processed [6] (Willcox et al., 2003).
En Côte Ivoire, fresh tomato production was estimated by the FAO in 2014 at 32,364 tons per year and increased to 44078 tons in 2018.Tomatoes are one of the main revenue crops in vegetable farming because many actors (producers and traders) make a living from tomato production and marketing (Coulibaly et al., 2019). However, environmental degradation is occurring due to the use of chemicals for both soil fertilization and plant treatments to increase tomato production.
In an effort to significantly reduce the use of chemicals, several studies have been conducted on biological control with satisfactory results. A study focused on composting showed that it improves crop yields compared to chemical fertilizers (Outéndé, 2016 , 2010). It is in this context that our work aims to improve the cultivation of tomato through the use of plant extracts.

Collection and treatment of plant material
The plant material consisted of leaves of Alchornea cordifolia, Tithonia diversifolia, and Mezoneuron benthamianum. These leaves were collected in the locality of Daloa during the month of May 2020 and were used for the treatment of the tomato crop soil. Fresh harvested leaves were shade dried at room temperature in the laboratory (25 to 27°c±2) for three weeks, as exposure to sunlight often reduces their efficacy (Anjarwalla et al., 2016). Furthermore, the dried leaves were powdered separately using a grinding machine (RETSCH type: SK100/C Gusseinsen) to obtain the powdered ones.

Setting up the experimental plot
For the realization of the experiment, a plot of 68 m2 was weeded with a machete and then weeded with a daba. Then 6 ridges of 3 m by 3.5 m were made. On each ridge 7 lines separated by 40 cm were made and on each line 6 sowing points separated by 50 cm were also made. The experimental set-up consisted of two completely randomized blocks of 6 ridges. Each ridge constituted a treatment and each treatment consisted of 7 lines. Each treatment was repeated twice.

Treatments
Quantities of 5 and 15 g of Alchornea cordifolia, Tithonia diversifolia, and Mezoneuron benthamianum powders were weighed for the treatment of the crop soil at the level of the pits. These treatments were performed as follows: -Treatment 1: cultivation soil treated with the powdery extracts on the day of transplanting -Treatment 2: cultivation soil treated with powdery extracts one week before transplanting -Treatment 3: cultivation soil treated with powdery extracts one month before transplanting.

Transplanting of plants
Tomato plants aged 21 days were transplanted at the level of the sowing points made with the different treatments. Watering was done twice a day for eight weeks and once a day until harvest. Regular weeding was done to maintain the plot. The staking of the plants was carried out four weeks after transplanting.

Data collection
Plant survival rate, growth and yield parameters were evaluated. Plant survival rate was recorded at three days, seven days and two weeks after transplanting. The survival rate was calculated according to formula (1).  (2) ym: average observed parameter; xi: observed parameter; xp: total number of plants observed.
Yield parameters were recorded from four weeks for the number of flowers and five weeks for the number of fruits.

Statistical Analysis
Data were subjected to a multi-factor analysis of variance (ANOVA) using STATISTCA 7.1 software. ANOVA was used to evaluate the effect of the extracts of the three plants on the agro-morphological parameters and the incidence and severity of diseases. When a significant difference was observed (P<0.05) between the different factors, multiple comparisons were performed using the LSD Fisher test at the 5% threshold.

Effect of A. cordifolia, T. diversifolia and M. benthamianum extracts on tomato plant survival rates
The survival rates of tomato plants ranged from 80.50 to 100 %. These rates were higher for the A. cordifolia, (94.44 to 100 %) and T. diversifolia (91.67 to 97.17 %) treatments one week and one month before transplanting. On the other hand, for M. benthamianum, it is rather the treatments on the day of transplanting and one week before transplanting at the quantity 5 g that gives the best survival rates. However, statistical analysis showed that there was no significant difference (P˃0.05) between the survival rates with the different treatments of the extracts of the three plants (

Effects of A. cordifolia, T. diversifolia and M. benthamianum extracts on agromorphological parameters of tomato
The effectiveness of the plant extracts used varied according to the plant species and agromorphological parameters studied. Thus, statistical analysis showed a significant difference (P< 0.05) in the span, leaf area and number of flowers. However, plant size, number of leaves, crown circumference, number of branches and number of fruits were not influenced by the type of extract (P > 0.05) ( Table  2). Also, Alchornea obtained the highest values in some parameters.

Effects of A. cordifolia extracts on agromorphological parameters of tomato
Agromorphological parameters of tomato plants treated with A. cordifolia varied with concentration and soil treatment period. Thus, the concentration 15 g (C2) of the soil treated one week before transplanting (treatment 2) recorded the highest values for the agromorphological parameters, except for the number of branches, whose highest value was obtained at the concentration 5 g (C1) of the soil treated one month before transplanting (treatment 3). The smallest values were obtained at the concentration 15 g (C2) of the treated soil on the day of transplanting (treatment 1). Statistical analysis showed a highly significant effect (P<0.01) of the treatments performed on the different parameters studied ( Table 3).

Effects of T. diversifolia extracts on agromorphological parameters of tomato
The effect of T. diversifolia also varied according to concentrations and treatments on agromorphological parameters. Statistical analysis showed a highly significant difference (P<0.01) among the studied parameters. The concentration 5 g (C1) of the soil treated one month before transplanting (treatment 3) recorded the highest values for the different parameters, except for the number of flowers, neck circumference and number of fruits, for which the highest values were obtained at the concentration 15 g (C2) of the same treatment (

IV. DISSCUSSION
Tomato is a very demanding crop in terms of water but also in terms of mineral elements, which makes the periodic replenishment of the soil reserves in these elements essential to maintain a good productivity. The powdery extracts of T. diversifolia, A. cordifolia and M. benthamianum were used to improve the fertility parameters of tomato growing soil.
The results show that the survival or recovery rates of the seedlings did not vary from one treatment to another, but the values remained high (80 to 100%). This result shows that the treatments performed influenced the recovery of the seedlings or that the vigor of the seedlings used favored their recovery. Indeed, the work of Ojetayo et al. (2011) and Musas (2012) showed that the recovery rates of vegetable plants from the nursery does not depend on the mineral elements contained in the soil but rather on the vigor of the plants. Also the work of Soro et al. 2008 showed that the age of transplanting of nursery tomato plants influences the mortality rate of the plants. These authors showed that plants aged 21 to 25 days are more resistant to attacks by Pythium sp. responsible for the death of young plants.
Treatments performed on tomato plants showed that the powdery extracts of the three plants applied four weeks before transplanting of the plants was more effective on morphological and production parameters of tomato. This could be explained by the synchronization of nutrient release from the extracts during their decomposition and assimilation by the plant. Indeed, Cobo et al. (2002) showed that the rate of decomposition of organic matter and the increase in yields was closely related to the timing between the release of nutrients and their assimilation by the plant. The various extracts incorporated into the soil thus appear to have a suitable decomposition rate that allowed the plant to assimilate a large proportion of the nutrients released during the decomposition of the organic matter. Also, an increase in parameters such as, number of flowers, spread and leaf area was recorded on the plants whose soils were treated with Alchornea cordifolia. This would result from the importance and the quantity of nutrients such as phosphorus, nitrogen, potassium contained in this extract which contribute to the nutrition of the plant. Indeed, Alchornea cordifolia is a plant that is found in Ivorian fallow soils and contributes to increase the organic matter of the soil. (Solanaceae), Anacardium sp. (Anacardiaceae) to minimize the severity of whitefly virosis and increase the yield of treated plots. This is explained by the fact that the extracts of these plants contain chemical substances such as terpenoids, steroidal heterosides, flavonoids, tannins, saponins, carbohydrates that act on the pest population and thus reduce their infections.

V. CONCLUSION
The results of this study showed that the powdery extracts of A. cordifolia, T. diversifolia and M. benthamianum had satisfactory effects on the improvement of growth and development parameters of tomato plants. However, only the Alchornea treatments had more significant effects on the studied parameters. For the different concentrations of plant extracts studied, C1 (5 g) gave the best results. It is therefore the optimal dose for treatment efficiency. The results also showed that the treatment of the soil one week before transplanting gave the best agromorphological parameters for A. cordifolia and M. benthamianum contrary to T. diversifolia which records the highest parameters when the treatments are done one month before transplanting. The work carried out showed the capacity of the extracts of these plants to be used to boost quantitatively and qualitatively the production of tomato