Breeding and High-yield Cultivation

Wei DUAN Shengli LIU Yantao LIU Peng WANG Hongye DONG

Techniques for Oil Sunflower New Variety "Xin Kui No.27"

Abstract This paper introduced the breeding process， characteristics， yield performance， disease resistance， quality characters， and suitable production areas of the new early-maturing oil sunflower variety "Xin Kui No.27"， and summarized high-yield cultivation techniques based on large-area continuous cultivation demonstration to serve agricultural production.

Key words New variety of oil sunflower; "Xin Kui No.27"; Breeding; Cultivation Technology

Received： October 3， 2021  Accepted： December 1， 2021

Supported by China Agriculture Research System of MOF and MARA （CARS-14-1-12）; Scientific and Technological Research Project in Key Areas of the Corps （2021AB011）; Nine Division Science and Technology Planning Project （2021JS007）.

Wei DUAN （1968-）， male， P. R. China， researcher， master， devoted to research about new variety breeding， high-yield cultivation technology research and popularization of sunflower.

*Corresponding author. E-mail： 495437597@qq.com.

Sunflower is an important oil crop and economic crop in China. It has unique regional advantages and the characteristics of good salt and alkali tolerance， good barren tolerance， strong drought resistance， strong cold resistance， short growth period， and strong adaptability. It has high seed oil content and excellent oil quality， and plays an important role in improving soil improvement， adjusting planting industry structure， increasing multiple cropping index and increasing farmers’ income. Through the application of new breeding technologies and the creation of high-quality， disease-resistant and stress-resistant sunflower germplasms， new varieties with outstanding dominant traits and excellent comprehensive traits have been selected， and combining the application of high-yield and high-efficiency supporting technologies and the industrialization of high-quality seeds， these new varieties can serve agricultural production to meet the needs of sunflower production in multi-cropping wheat areas following wheat harvest and in cold mountainous areas.

Selection Process

Oil sunflower "Xin Kui No.27" is an early-maturing sunflower hybrid selected by Xinjiang Academy of Agricultural Sciences for oil use. In 2004， self-bred inbred line 950C-132212 was crossed with the oil sunflower hybrid TSC3012. After selection in segregating generations and continuous backcrossing， testcross and screening was performed from the 7th generation， and the genetically stable sterile line BH4-92432 and a maintainer line were bred. In 2004， oil sunflower hybrid NX00997 was bagged and self-crossed， and systematic selection was performed in segregating generations through propagation in the south and cultivation in the north. The testcross combining ability test was started from the 7th generation， and the genetically stable restorer line XX4-a211 was obtained.

In 2008， sterile line BH4-92432A and restorer line XX4-a211 were used to prepare hybrid AR8-0501. The obtained hybrid participated the variety tests conducted from 2009 to 2011 and the oil sunflower reseeding regional tests in Xinjiang Autonomous Region from 2012 to 2013， and oil sunflower reseeding production tests were conducted in Xinjiang Autonomous Region in 2014. It was approved by the Xinjiang Uygur Autonomous Region Crop Variety Approval Committee in January 2016， under the approval number Xinshenkui 2015 No.19.

Characteristics

"Xin Kui No.27"is an early-maturing oil sunflower variety with a growth period of 99 d for spring sowing and 84-87 d for reseeding.

Plant character

The leaves are dark green， and the plants grow neatly with a plant height of 180.3 cm. Each plant has 27 leaves， and the stem thickness is 2.02 cm.

Sunflower head characters

The tongue-shaped flowers are yellow， and there is a large amount of tubular pollen. The sunflower heads are convex and have an inclination of level 2-3， and the diameter of flower plates is 17.02 cm. The grain weight of single plate is 68.85 g， and the seed setting rate is 89.76%.

Seed character

The grains are long and tapered， and have black and dark gray stripes on seed coats. The weight per 100 seeds is 5.58 g， and the kernel rate is 66.71%. The oil content is 51.4% in spring seeds， and 43.0% in the seeds from reseeding cultivation.

Stress resistance

The variety is resistant to lodging， downy mildew， black spot and rust.

Yield Performance

Variety test

In the comparison test of oil sunflower reseeding varieties in Xinjiang Academy of Agricultural Reclamation Sciences， the average seed yield was 3 730.95 kg/hm2 in 2009， showing an increase of 7.43% compared with the control "Xin Kui No.10". In the comparison experiment of oil sunflower spring-sown varieties in Xinjiang Academy of Agricultural Sciences， the average seed yield was 3 355.5 kg/hm2 from 2010 to 2011， exhibiting an increase of 13.37% compared with the control "Xin Kui No.10".

From 2009 to 2014， in the fifth oil sunflower line comparison test in Shihezi， Xinjiang and Beitun， Xinjiang， the average seed yield was 3 682.95 kg/hm2， which increased by 12.37% compared with the control "Xin Kui No.10" （3 277.35 kg/hm2）.

Reseeding regional test of oil sunflower in Xinjiang Autonomous Region

In the 2012 reseeding regional test in Xinjiang Autonomous Region， the average yield of "Xin Kui No.27"was 2 220.0 kg/hm2， which increased by 7.2% compared with the control "Xin Kui No.10" （2 071.5 kg/hm2）. In the 2013 reseeding regional test， the average yield of "Xin Kui No.27"was 4 003.5 kg/hm2， which was 13.56% higher than the control "Xin Kui No.10" （2 926.5 kg/hm2）. "Xin Kui No.27" showed high yield and good stability. The average yield in the two years was 3 497.4 kg/hm2， showing an increase of 8.72% compared with the control. The growth period was 86 d， one day later than the control.

Reseeding production test of oil sunflower in Xinjiang Autonomous Region

In the 2014 reseeding production test of oil sunflower in Xinjiang Autonomous Region， "Xin Kui No.27" had an average yield of 3 696.75 kg/hm2， which increased by 2.52% compared with the control "Xin Kui No.10". The growth period was 87 d， which was 3 d longer than the control.

Resistance Identification

At the Changji test site for reseeding production tests of oil sunflower in Xinjiang Autonomous Region， "Xin Kui No.27" was identified by plant protection and plant inspection station of Changji Agricultural Technology Center in fields. The results showed that in "Xin Kui No.27"， the disease index of rust disease was 0.14%， and the disease index of black spot disease was 0.18%， which was significantly lower than that of the control and other varieties. It was moderately resistant to rust and black spot.

According to the investigation at the Shihezi test site at the Plant Protection Station of the Shihezi Agricultural Technology Extension Station in Xinjiang， no downy mildew， rust， brown spot， black stem disease were found in "Xin Kui No.27"， and the disease index of sclerotinia was 1.5%.

Quality Characters

The oil and product quality supervision， inspection and testing center of the Ministry of Agriculture （Urumqi） showed that the oil content in the seeds of "Xin Kui No.27" from the reseeding season was 43.0%.

Suitable production areas

"Xin Kui No.27" is suitable for planting in high-altitude cold agricultural areas， and in winter wheat areas along the Wuyi Highway in Xinjiang having a long frost-free period and sufficient light and heat resources after wheat harvest[1].

Spring-sowing High-yield Cultivation Techniques

Site selection and soil preparation

Mildly to moderately alkali-saline land or loam land with medium fertility and above can be selected. The land should be level and easy to irrigate. Crop rotation for more than three years should be implemented. Through crop rotation， the nutrients of the soil can be used in a coordinated manner and the physical and chemical properties of the soil can be improved. The selection of continuous cropping and alternate cropping fields should be avoided， and it is best to choose the fields with a previous crop of maize， wheat and melons， free of long-acting herbicide residues.

In order to increase the active soil layer， plowing is carried out after autumn crops are harvested， and the saline-alkali soil is subjected to deep ploughing to leach the upper layer of salt to the lower layer. The crop can be grown in a safe saline-alkali range in the early stage to increase the survival rate of seedlings.

Soil leveling and preparation should meet the requirements that the topsoil is fine and the bottom is solid， the topsoil is finely broken， and the ground surface is flat， and has no furrows， ridges and debris that affect sowing.

Sowing on reasonable sowing date

If the seedlings of "Xin Kui No.27" are planted too early， the seedlings will be difficult to emerge and weak seedlings will be vulnerable to freezing damage and pest damage due to the low and unstable air temperature and ground temperature at that time. A reasonable sowing date should be determined according to the actual situation in various parts of China. Appropriately adjusting the sowing date can avoid high temperature during the flowering period， which is beneficial to increase the seed setting rate of sunflower.

The suitable sowing period is early and mid-April for spring sowing. Precise dibble seeding or artificial sowing can be adopted at a sowing rate of about 6 kg/hm2 with a sowing depth of 4-5 cm， and the seeds are slightly suppressed[2].

Precision management

Irrigation is performed for 5-6 d after emergence， and the germination of seeds in the field is checked. If there are long vacant strips， seeds are re-sown in time after pre-germination. Rainfall after sowing makes it easy to form on the soil surface hard cover compaction， which should be broken in time before the sprouts break out.

Final singling of seedlings is started at the stage of one pair of true leaves and finished at the stage of two pairs of true leaves. Early final singling can promote early emergence， growth and robustness of seedlings. For the plots with severe pests and diseases or susceptible to saline-alkali， final singling can be set a little later， but should not be after the emergence of three pairs of true leaves at the latest.

Intertillage can be performed when seedlings emerge in rows， and 1 to 2 times of intertillage can be conducted combining with weeding between rows. The first intertillage is performed before  final singling of seedlings with a depth of 8 cm， and the second intertillage is performed 7-10 d after final singling of seedlings with a depth of 12-15 cm. Intertillage should be wide and deep under the premise of not damaging the seedlings or burying the seedlings， in order to achieve better effects of weeding and raising the ground temperature. Manual weeding can eliminate weeds and reduce ineffective consumption of nutrients and water.

Reasonable dense planting can improve the utilization rate of light energy， ensure that the population has the largest production capacity， and increase the yield per unit area. Reasonable dense planting can also increase the oil content， reduce the empty grain rate， and reduce the hull rate. The seedling density is 75 000-82 500 plants/hm2， and no double plants are left.

Reasonable fertilization and irrigation

Strong plants are cultivated through field management measures such as water and fertilizer regulation. The plants are irrigated at the right time according to the soil and plant growth conditions， and there is no need to deliberately expose the plants to drought which will affect normal growth. For plots without the application of base fertilizer and seed fertilizer， appropriate fertilization （dripping monoammonium 60 kg/hm2， urea 45 kg/hm2） at the 8-10 leaf stage can be conducted to meet the nutrient needs of seedling growth. The plants are irrigated 3 to 4 times during the whole growth period. If the sunflower blooms with high temperature， rainy， low-sunshine and other weather， it will affect normal fruiting and reduce yield. Therefore， the plots with conditions can be watered shallowly once during the blooming period to reduce field temperature， increase humidity and improve seed setting.

After the sunflower blooms， water is indispensable. The principle of "watering when the soil is observed to be dry" can promote large and full grains， high yield and high quality. It is recommended not to irrigate in the late stage of maturity， so as to avoid causing in the field excessive humidity which easily induces sclerotinia[3] .

Under medium soil fertility conditions， it is recommended to topdress 3 times with a total of 180-225 kg/hm2 of monoammonium， 300-375 kg/hm2 of urea， and 180-225 kg/hm2 of potassium sulfate. Potassium fertilizers can enhance late leaf function， improve disease resistance and control and prevent lodging. Fertilization is combined with irrigation. In drip irrigation fields， the amount of fertilizers for each application is determined according to the irrigation cycle and the remaining planned amount of fertilizers， and water-soluble fertilizers are selected and applied with water drops.

Supplementary pollination

Sunflower is an insect-pollinated and cross-pollinated crop， which requires insects to pollinate to normally fruit and form seeds. In recent years， due to the extensive use of chemical pesticides， the number of insects has decreased， resulting in a low pollination rate of sunflowers.

Bee-assisted pollination during the flowering period can significantly increase production. Beehives are placed at a distance of about 150 m from water sources. If necessary， artificial assisted pollination will be started when sunflower enters the flowering period 2 to 3 d.

Pests and diseases

Pest damage is mostly manifested as direct feeding， resulting in a decrease in the number of florets. Diseases are mostly manifested as affecting leaf photosynthesis or the absorption and transportation of nutrients and water， resulting in malnutrition of plants and the condition that florets cannot form and grow normally. It is necessary to prevent and control pests in time. We should also prevent and control the occurrence and development of diseases， use medicines rationally， and reduce the losses caused by diseases.

Timely harvest

The best harvest period is when the leaves on the back of sunflower plates and the middle and upper leaves of plants become yellow， the shells of the grains become hard and the grains show an inherent color. Harvesting too early means insufficient grain maturity， which will affect the yield. Harvesting too late will cause seeds to lose water， and the seeds will no longer be arranged tightly， and will fall during the harvesting process. After threshing， the site should be clean and dry when drying. When the kernels are hard after the seeds are peeled， they should be cleaned immediately[4] and packaged.

Agricultural Biotechnology2022

Key Points of Reseeding Cultivation Techniques

The reseeding of "Xin Kui No.27" （along the Wuyi Highway in Xinjiang） should be conducted before July 10 （according to the irrigation for emergence） with a seeding rate of 6 kg/hm2， and the seeding depth is 3-4 cm. Proper measures are taken to keep 82 500-90 000 plants/hm2 in the field.

After the emergence of seedlings， soil loosening， weeding and final singling are performed in time， intertillage and topdressing are performed early， and the plants are managed diligently and promoted to the end. The plants are irrigated twice from budding to maturity. When sowing， triple superphosphate 120 kg/hm2 and urea 45 kg/hm2 are applied in furrows with seeds as the seed fertilizer. Topdressing is performed with urea 300-375 kg/hm2 during the intertillage and furrowing period to ensure the supply of water and fertilizers during the flower bud period.

After harvest， the film-covered fields should be cleared of residual film in time to purify the farmland and prevent film pollution. Residues of diseased plants are taken out of the field in time and burned or buried deeply to prevent pathogenic bacteria from overwintering in the soil and bringing diseases to crops in the

coming year. After harvest， the grains should be stored in a low-temperature， dry， ventilated environment to prevent moisture and leakage.

References

[1] LIU WJ， LI HH， WEI LM， et al. The influence of different sowing dates on sunflower growth， yield and occurrence of diseases and pests[J]. Jiangsu Agricultural Sciences， 2015， 43（2）： 110-112. （in Chinese）.

[2] DUAN W， LI WY. Breeding and high-yied cultivation technique of oil sunflower new variety "Xin Kui No.19" [J]. Seed， 2012， 31（1）： 110-112. （in Chinese）.

[3] LIU SL， LIU YT， WANG P， et al. Breeding and high-yield cultivation techniques for oil sunflower new variety： "Xin Kui No.26"[J]. Horticulture & Seed. 2017（7）： 65-66， 75. （in Chinese）.

[4] DUAN W， LI WY. Simple cleaning and selection equipment for sunflower seeds： China， 201320359039.3[P]. 2013-11-20. （in Chinese）.

Editor： Yingzhi GUANG  Proofreader： Xinxiu ZHU