Response of Foeniculum Vulgare Plant to NPK Doses and Some Biostumulants

Introduction

Fennel (Foeniculum Vulgare Mil , Fam. Apiaceae ) is a strong aromatic and medicinal plant native to North Africa, Mediterranean region, southern Europe and Asia. In Egypt, fennel fruits are considered an important export spice, the country cultivates about 11000 feddans of fennel, mostly in Assiut and Qena Governorates, as a winter annual herb. The constituents of fennel volatile oil are anethole, limonene, fenchone, estragole, safrole, α-pinene, camphene, β-pinene, β-myrcene and p-cymene (Saravanaperumal and Terza, 2012).The fruits of the plant are used for folk medicine for its antispasmodic and stomachic, sedative, balsamic, cardiotonic, digestive, lactogogue and tonic properties.The essential oil is used for cosmetics and pharmaceutical products and it has a valuable antioxidant, antibacterial, anticancer and antifungal activity (Bahmani et al., 2012). Fertilizer management is an important factor for a successful growth of officinal plants and the identity of suitable fertilizers in plants could have the desirable effects on quantitative and qualitative indices (Arab et al., 2015).  Mineral fertilizers (e.g. N, P, K…etc.) have a number of different negative influences on both the environment and health of humans due to accumulation of nitrate in growing plants, ground water and soil. Overusing chemical fertilizers has changed the biological ecosystem, affecting non-target organisms and adversely influencing microorganisms in the soil. To mitigate the risk of the bad effects of mineral fertilizers, it is necessary to replace chemical fertilizers by organic or biological fertilizers which are able to provide plant nutrients and also increase the sustainability of agro-ecosystems in the long term (Moradi et al., 2011). Plant bio-stimulants (e.g. salicylic acid, tryptophan and ascorbic acid) are effective when applied in small doses, thus leads to the plant growth and production enhancement (Li and Ni, 1996). Plant bio-stimulants are organic materials that appear to impact several metabolic procedures such as respiration, photosynthesis, nucleic acid synthesis and ion uptake and when applied in small quantities, improve the plant growth and development (Castro and Vieira, 2001). Therefore, this work was conducted to increasing the growth, essential oil% and yield productivity of fennel plant, as well as, reduce environmental pollution by reducing rates of N, P, and K fertilizers by sprinkling with salicylic, tryptophan and ascorbic acids.

Material and Methods

Fennel seeds of local variety (Foeniculum Vulgare Mill) was sown on 1^st and 2^nd Nov.2016 and 2017 seasons, respectively in rows 60 cm apart and hills 30 cm in between. The experimental unit was 2X2 m² contains 24 plants (4 rows, each row was cultured with 6 plants). After complete germination the seedlings were thinned to one plant / hill on 21^st and 23^rd Dec. 2016 and 2017 seasons, respectively.Soil samples of the experimental area in private Farm at Maghnin village, Koum Hamada city, El-Behera Governorate, Egypt, were collected at 10, 20 and 30 cm in depth then mixed carefully to determine the physical and chemical parameters (Table 1) according to Jackson (1973).   

Table (1). Some physical and chemical parameters of the experimental soil.

Physical parameters

Chemical parameters

The experiment design:

The experiment was setup as a split plot design whereas, NPK fertilizers were arranged at random in the main plots and the used acids were arranged at random in the subplots, The experiment was replicated three times each replicate contained 20 treatments (4 NPK doses X 5 treatments of used acids).

The treatments of NPK were: 1) 100% NPK dose (suggested dose = 150+150+50kg/fed of ammonium sulphate (20.5% N), calcium super phosphate (15.5 %P₂O₅) and potassium sulphate (48% K₂O), respectively, 2) 75% NPK dose, 3) 50% NPK dose, and 4) 25% NPK dose. Where, calcium superphosphate was added as one dose at soil preparation before planting. While ammonium sulphate and potassium sulphate were divided into two equal doses, first dose was added two days after the thinning and the second one was added one month from the first dose in the two seasons.

The treatments of the used acids were: 1) Control (disteld water), 2) 200 mg/l of each ascorbic acid (AA) and salisylic acid (SA), 3) 200 mg/l of each (AA)and tryptophan acid (TA), 4) 200 mg/l  of each (SA) and (TA), and 5) 100 mg/l of each (AA), (SA) and (TA).Where, the plants were sprayed 3 times on 26^th  and  30^th Dec., 26^th  and 30^th Jan. and 25^th  Feb. and 1^st March in 2016/217 and 2017/2018 seasons ,respectively. The plants were sprayed in morning to run off.

Data recorded, at the full flowering stage on 15^th April and 21^st for both seasons ,respectively, the following traits were measured 1) Vegetative and flowering traits [ plant  height(cm),  shoots number/plant, main stem diameter at 5 cm from soil surface(mm), umbels number/plant and umbels diameter (cm)],2) leaf green color degree (SPAD units) was estimated by Minolta SPAD-502, Japan (Markwell et al ., 1995), 3) Leaf NPK , where N% was determined by the modified micro–Kejeldahle method (Chemists and Horwitz, 1990), P% by colorimetrically spectronic (20) spectrophotometer (Murphy and Riley, 1962), and K% by flame photometer (Cotteine et al.,1982) and 4) At harvesting time on  4^th Jun and 1^st Jun. in the two seasons,  respectively. The following traits were recorded. Dry weight/plant (g), fruits weight/ plant (g), weight of 100 fruits (g) , total carbohydrate percentage in seeds according to Herbert et al. (1971), essential oil % in the air dried fruits (British Pharmacopoeia, 1963), whereas,

 essential oil % =  × 100 and essential oil yield/plant = essential oil % × fruits weight /plant (ml).

The statistical analysis:

Duncan’s Multiple Rang Test was used to compare the treatments mean at 0.05 level of probabily according to Snedecor and Cochran (1989).

Results and Discussion

3.1 Effect of NPK doses, used acids and their interaction on vegetative and flowering parameters:

In respect to NPK doses, data in Table 2 showed that 100% NPK dose resulted in significant increases in vegetative growth traits (plant height, shoots number/plant main stem diameter, leaf green color degree (LGCD) and dry weight /plant) and flowering traits (umbels number /plant and umbel diameter) in comparing to the 75, 50 and 25% NPK doses in the two seasons. Too, it is noticed that the differences among the NPK doses reached the significant level (p > 0.05) for all such traits mentioned before,  expect for number of shoots in the first season and umbel diameter in the second one,  whereas the difference between 100% and 75% doses did not reach the significant level.

This result may be due to that 100% suggested NPK dose was suitable for reaching the soil with N, P, and K nutrients, because N, P and K are essential to all crops .N is the element that most limits crop yield.

Most of N in plants is an organic form: nucleic acids, amino acids proteins, some vitamins, harmonies, membrane component, coenzymes and pigment. P is an essential component of the energy transfer compounds (ATP, ADP and other nuclei proteins), the genetic information system, cell membranes and phospho-lipids. K is serving as an enzyme activator or cofactor for some enzymes, it also aided in the maintenance of osmotic potential and water uptake (Khorshidi et al., 2009). These results are in accordance to these of Abaas (2014) who found that the highest values of all growth parameters of sage plant were obtained at 230 kg N ha^-1 +80 kg P ha^-1. He added that the effect of N and P may belong to role of them in accumulation of chlorophyle material which very important in photosynthesis process and other physiological processes in plant. Likewise, Waskela et al. (2017) cleared that 60+40+40 NPK kg ha^-1 exhibited significant maximum growth, yield attributes, yield and quality of fennel. Additionally, Al-Mansour et al. (2018) revealed that application of recommended FYM (10 t ha^-1) along with recommended NPK (160:80:80 kg ha^-1) recorded the highest fresh herbage yield of sweet basil.

Table (2). The Mean Effect of NPK doses on vegetative and flowering traits of                   fennel in  2016/2017 and 2017/2018 seasons

In the same row means followed by the same letter are not significantly different according to DMRT at 0.05 level probability

Regarding the effect of acids treatments data in Table 3 cleared that all treatments of the used acids exhibited significant increases in plant height, shoots number/plant, stem diameter, LGCD, dry weight/plant, umbels number/plant and umbel diameter in compassion to the control treatment in the two seasons expect for shoots number in the first season, where the differences among the all treatment did not reach the significant level. In the sometime, the treatment 100 mg/l of each AA, SA and TA significantly increased the values of aforementioned traits over than the after used stimulants treatments in the both seasons, with exception in case of shoots number in the first season.

It is abvioused from the resulted that the most effectiveness treatment was 100 mg/l of each AA, SA, and TA may be 100 mg/l of each occurred a balance among the used stimulants that reflected on the plant growth .Also, amino acids play wide roles in plants including acting as regulatory and signaling molecules. Amino acids affect synthesis and activity of some enzymes, gene expression, and redox homeostasis (Rai, 2002). Too SA acts on the growth and development of the plant and, for this reason, is also regarded as a plant hormone (Liu et al., 2011). This result was supported by Youssef (2014) revealed that the tallest plant, the highest number of flowering heads and their fresh and dry weights of Echinacea purpurea were recorded by 200ppm tryptophan combined with 150ppm Zn. Likewise, Ali et al. (2017) on fennel plants found that 100 or 200 ppm ascorbic acid or salicylic acid improved plant growth and flowering traits.

Table (3). The Mean Effect of the used acids on vegetative and flowering traits of  fennel in 2016/2017 and 2017/2018 seasons

In the same row means followed by the same letter are not significantly different according to DMRT at 0.05 level probability

Table (4). Effect of interaction of NPK doses and used acids on vegetative and flowering traits of fennel in 2016/2017 and 2017/2018 seasons

In the same column means followed by the same letter are not significantly different according to DMRT at 0.05 level probability

Concerning the interaction effect, the presented results in Table 4 demonstrated that the treatment of 100% NPK dose combined with 100 mg/l of each AA, SA, and TA caused significant increases in plant height, shoots number / plant, main steam diameter, leaf green color degree, dry weight / plant umbels number / plant and umbel diameter in comparison to the other interaction treatments in the two seasons. On the other side, the treatment of 25% NPK dose without spray with stimulants gave the least significant values of such traits, expect for shoots number / plant in the first season .where this fact result from 50% NPK dose without spray with stimulants. The differences among the interaction treatments reached the significant level in the most cases during the both seasons.

These results are in harmony with those of El- Tarawy et al. (2012) who reported that the treatment of 75% NPK (112.5, 112.5 and 37.5 kg /fed of ammonium sulphate, calcium superphosphate and potassium sulphate, respectively) plus 200 mg/l of each ascorbic and salicylic acids recorded the best results of branches number /plant, herb fresh and dry weights and umbels number/plant. El-Mahrouk et al. (2016) mentioned that the significantly highest values of plant height, shoots number / plant and fresh and dry

weights of sage plant resulted from ¾ NPK dose ( 225+150+75 kg /fed of ammonium sulphate, calcium superphosphate and potassium sulphate , respectively) plus 200 ppm ascorbic acid .

 Effect of NPK doses, used stimulants and their interaction on seed yield, essential oil and chemical composition.

 As for NPK doses, data in Table (5) showed that the treatment of 100% NPK dose was the most significant effective in increasing weight of 100 seeds, essential oil % and yield/plant, leaf N, P and K% and total carbohydrates% in fruits in comparing to the other NPK doses in the two seasons .While the significantly highest value of seed yield / plant was recorded for 75%NPK dose in the both seasons. It is clear from the results that the values of such traits decreased gradually with decreasing NPK doses with one exception of seed yield / plant whereas, 75% NPK dose caused an increase over than 100% NPK dose in the two seasons . The results indicated that 100% NPK dose was the suitable for yield, essential oil productively and chemical composition, that may be referred to that NPK play important roles in the physiological, chemical and biochemical processes in plant cell and the genetic information system, which positively reflect on the plant development and its yield and chemical composition. These results confirmed with those of Nik et al. (2011) on Ajowan plant who found that 120 kg, N 200 kg P, 150 kg K , 25kg Zn and 25 kg Mg per ha had significant effect on seed yield . Yousuf et al. (2014) mentioned that N, P, K and S at 70, 50, 30 and 20 kg / ha gave the highest seed yield of coriander. Waskela et al. (2017) found that NPK at 60+60+40 kg/ ha exhibited significant maximum yield of fennel. Al –Mansour et al. (2018) showed that the higher essential oil % and yield of sweet basil resulted from 10 t/ha FYM +NPK (160+30+80kg /ha).

Concerning AA, SA, and TA effect, data in Table 6 pointed out that the used treatments of stimulants caused significant increases in yield, essential oil and chemical composition parameters under study over than the control treatment. Meanwhile, the treatment of 100 mg/l of each AA, SA, and TA had positive pronounced effect on such traits in comparing to the other ones in the two seasons. These results may be attributed to that 100 mg/l of each AA, SA, and TA was the suitable level, which caused better balance among them, that reflected on the plant yield and chemical composition. Also, a plant bio-stimulant is any substance or microorganism applied to plants with the aim to enhance nutrition efficiency, abiotic stress tolerance and/or crop quality traits, regardless of its nutrients content (Patrick, 2015). SA, AA and TA play crucial roles in the regulation of physiological and biochemical processes during the entire life span of the plant (Karnok, 2000; Vicente and Plasencia, 2011 and Rasmy et al., 2012).

Table (5). Effect of NPK doses on seed yield, essential oil and chemical in 2016/2017 and 2017/2018 seasons composition of fennel               

In the same row means followed by the same letter are not significantly different according to DMRT at 0.05 level probability

These results are similar to thoseofIbrahim and Taha (2016) revealed that the highest values of total soluble sugars and N, P and K % of Ficus  microcarpa were recorded for the plants treated with 150 mg/l tryptophan. Ali et al. (2017) found that application of AA at 100 mg/l gave the maximum essential oil yield of fennel. Additionally, Yeganehpoor et al. (2017) reported that SA at 1mM led to increment in seed oil of coriander.

Table (6). Effect of the used acids on seed yield essential oil and chemical  

                 composition fennel in 2016/2017 and 2017/2018 seasons

In the same row means followed by the same letter are not significantly different according to DMRT at 0.05 level probability

In regard to the interaction effect data in Table 7 indicated that the combination treatments of NPK doses and used stimulants had differently exhibit effects on seed yield / plant, essential oil % and yield / plant, weight of 100 seed and percentages of N, P, K and carbohydrate in the two season. Meanwhile, the treatment of 100% NPK dose combined with 100 mg/l of each AA, SA and TA resulted in significant increases in such traits over than the other ones in the both seasons. In the same time, the plants received 25% NPK dose and did not treat with stimulants had the least significant values of such traits aforementioned in the two season.

These results are in agreement with those of El-Tarawy et al. (2012) revealed that total carbohydrate % and essential oil productivity of fennel were higher from application of 75% NPK dose + 200 ppm AA+SA. Also, El- Mahrouk et al. (2016) cleared that the essential oil yield / plant ,N,P,K  and carbohydrate % in sage plant resulted from ¾ NPK dose +200mg /l AA (NPK full dose is 300+200+100kg/fed of ammonium sulphate, calcium super phosphate and potassium sulphate, respectively ). Finally, Sakr et al. (2018) mentioned that extract of moringa at 6g/l, 600+300+150 kg /fed of NPK, respectively and aloe at 75 ml/l resulted in a positive increase in oil production and chemical composition of Pelargonium graveolens.

Table (7).Effect of interaction of NPK doses and used acids on seed yield, essential oil and chemical composition of fennel in 2016/2017 and 2017/2018 seasons

In the same column means followed by the same letter are not significantly different according to DMRT at 0.05 level probability