Effects of 12% Chlorothalonil and 12% Procymidone Smoke Agents on Physiology and Yield of Quinoa in Greenhouse

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1. Semi-arid Agricultural Engineering Technology Research Center of China, Shijiazhuang 050000, China; 2. Institute of Cereal and Oil Crops, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050035, China; 3. Agricultural and Rural Bureau of Handan District, Handan City, Handan 056001, China; 4. Agricultural and Rural Bureau of Congtai District, Handan City, Handan 05002, China; 5. Institude of Millet Crops, Hebei Academy of Agriculture and Forestry Sciences/Cereal Crops Research Laboratory of Hebei Province/National Foxtail Millet Improvement Center, Shijiazhuang 050035, China

Abstract [Objectives] To study the effects of 12% chlorothalonil and 12% procymidone smoke agent on physiology and yield of quinoa in greenhouse. [Methods] The chlorophyll content and photosynthesis rate of quinoa were determined by using the conventional application method of smoke agent at the dosage of 3 kg/ha. Finally, the total yield and increased yield of quinoa were calculated. [Results] The chlorophyll content and photosynthesis rate of leaves were all increased by two kinds of smoke agents, and the photosynthesis rate was also increased significantly. [Conclusions] These two smoke agents can promote the growth of quinoa, including the increase of chlorophyll and the enhancement of photosynthesis, and its further mechanism needs to be further discussed.

Key words Quinoa, Smoke agents, Pesticides

1 Introduction

Quinoa, native to the Andes in South America, has been cultivated for more than 5 000 years. It is the main traditional food of the Inca indigenous people, known by the Incas as "the mother of food", "the mother of grain" and "the true gold of the Andes". Its seeds and seedlings are edible, and quinoa has been recognized all over the world because of its high nutritional value and a variety of development and utilization values. The Food and Agriculture Organization of the United Nations (FAO) recommends quinoa as the perfect nutritious food that can meet all the basic material needs of the human body with the only single plant. It was first introduced to China in 1987 and the planting area gradually expanded in 2010. With the planting of quinoa, the edible value of quinoa seedlings has been more and more widely recognized. Quinoa vegetable is also very rich in nutrients and tastes good, and as a kind of green leafy vegetable, it is increasingly favored by consumers.

With the area of quinoa facility land increasing year by year, people pay more and more attention to the prevention and control of quinoa diseases. For the diseases such as downy mildew, anthrax, gray mildew, powdery mildew and early blight, it is necessary to seek a convenient, safe and effective agent to produce green organic quinoa. The practice shows that it is better to use chlorothalonil and procymidone smoke agents to control the above diseases in greenhouse and other facilities. The purpose of this project is to study the effect of smoke agent on photosynthesis and chlorophyll content of quinoa and its yield-increasing effect in greenhouse.

2 Materials and methods

2.1 MaterialsQuinoa cultivated in the greenhouse, 12% chlorothalonil smoke agent (Hebei Tangshan Xinhua Pesticide Co., Ltd.), 12% procymidone smoke agent (Henan Wuxing Pesticide Factory); ECA-PC1401 photosynthesis measuring instrument (Beijing Yikangnong Science and Technology Development Co., Ltd.), ECA-YLS02 chlorophyll measuring instrument (Beijing Yikangnong Science and Technology Development Co., Ltd.).

2.2 Methods

2.2.1Determination of chlorophyll content and photosynthesis rate. The representative greenhouses with good equipment conditions were selected, and the pesticide treatment was carried out by the above-mentioned conventional application way of smoke agent. In the scheduled days of the application of smoke agent, the automatic chlorophyll content meter and photosynthesis meter were used to determine the samples from multiple points in different treatment plots of the designated area. The determination results are summarized in Table 1.

2.2.2Statistical analysis of the effects of disease prevention and yield increase. Taking the greenhouse as a unit, 12% high-efficiency chlorothalonil and 12% procymidone were used for 4 times in the greenhouse of quinoa in autumn-winter season and in winter-spring season, respectively. The harvest results in different treatments were emphatically recorded, and the total yield and yield increase were calculated.

3 Results and analysis

3.1 Effects on physiological metabolism of vegetables

3.1.1Effects on chlorophyll content of vegetables. The results of Table 1 showed that the chlorophyll content of leaves increased significantly with the passage of time after quinoa was treated with the new agent. On the second day after fumigation, it could be seen that the two smoke agents had a significant effect on plants, and the growth rate reached 4.52% to 6.44%. On the fourth day after fumigation, it could be seen that the growth rate reached 8.78% to 10.10%, which produced a more significant effect.

Table 1 Effects of two kinds of smoke agents on chlorophyll content of quinoa leaves in greenhouse

TreatmentChlorophyll content∥mg/dm2(the afternoon of the second dayafter fumigation)Increase∥%Chlorophyll content∥mg/dm2(he afternoon of the fourth dayafter fumigation)Increase∥%12% high-efficiency chlorothalonil smoke agent6.834.527.5210.1012% procymidone smoke agent6.946.447.438.78CK6.52-6.83-

3.1.2Effects on photosynthesis of quinoa. From Table 2, it was found that the treatment and application of the two smoke agents also had a significant effect on the photosynthesis of quinoa. Table 2 showed the effects of the application of two kinds of smoke agents on the photosynthesis rate of quinoa.

Table 2 Effects of new agent on photosynthesis of quinoa (measured at 10:00 before ventilation on the fourth day after fumigation)

TreatmentPhotosynthesis rateμ/molco2sIncrease∥%12% high-efficiency chlorothalonilsmoke agent12.438.9912% procymidone smoke agent12.8713.0CK11.50-

Through the application of 12% high-efficiency chlorothalonil smoke agent, the photosynthesis rate increased by 8.99% after four days of application. Through the application of 12% high-efficiency procymidone smoke agent, the photosynthesis rate increased by 13.0% after four days of application. It could be seen that the two pragents could significantly improve the photosynthesis rate.

3.2 Effects on yield increase of vegetablesIt was known from Table 3 that in the Yongnian greenhouse in autumn-winter and winter-spring, the yield was increased by 21.79% and 16.43%, respectively, by using the new smoke agent of 12% high-efficiency chlorothalonil alternately. The yield was increased by 16.82% and 13.30%, respectively, with the application of 12% procymidone smoke agent.

Table 3 Effects of two new smoke agents on disease control and yield increase of quinoa

TreatmentQuinoa production during autumn-winterYield∥kg/haIncrease∥%Quinoa production during winter-springYield∥kg/haIncrease∥%12% high-efficiency chlorothalonil smoke agent23 89521.7925 08016.4312% procymidone smoke agent22 92016.8224 40513.30CK19 62021 540

4 Conclusions

The effective smoking rates of 12% high-efficiency chlorothalonil smoke agent and 12% procymidone smoke agent are mostly about 85%. Through the indoor multi-point field test and large area demonstration, it showed that its disease prevention and yield-increasing effect was good, and the smoke agent was uniformly and moderately dispersed in the greenhouse. It floated in the way of Brownian Motion for a long time, so it could penetrate the plant canopy and fall evenly on the front, side and back of the leaves, and the upper to the lower part of the quinoa canopy. The active and co-active substances might be atoms, particles, chemical zones or organic compounds, or nano-effects produced by nano-sized aerosol particles. This could significantly increase the content of chlorophyll and improve the photosynthetic efficiency. The increase of metabolic activity would naturally improve the disease resistance activity and plant productivity.