Effect of Fertigation and Foliar Application of Seaweed’s Bio Stimulant on Banana Yield

In order to shed light on the effect of the seaweed Ascophyllum nodosum (L.) bio stimulant on the banana fruit, foliar application (Fo), fertigation(F1) and a mix of both interventions (M) were done during 2018-2019 season on banana plants grown in South Lebanon compared with control (Ctrl). The period between flowering and harvest, the bunch weight, the weight and dimensions of fruit, were measured during the study. The results showed that the shortest period between flowering and harvest was observed on samples treated through foliar application (Fo), less with fertigation and then the mix of both (M). Those treatments were very effective in stimulating the weight of bunch and length of fruit, while a significant increase in the weight of fruit was noticed when both applications were done together (M). All treated modalities showed better performance compared with control. There was no difference in the diameter of fruit between all treatments. Therefore, the application of eco-friendly seaweed-based bio stimulant would be beneficial for the time of harvesting, and the size of banana fruits.


Introduction
Banana (Musa sp.), is an important fruit crop in sub-tropical and tropical countries. It is native to tropical south and Southeast Asia, cultivated in the world in an area of 4.8 million ha with global production of 99.99 million metric tons (Dombale et al., 2018).
Banana cultivation in Lebanon is widespread, in general, in coastal areas and in the south in particular. Export value of Lebanon Bananas, including plantains, fresh or dried was more than 12 million $ in 2014 (UN, 2014). However, due to Syrian war, the banana exports dropped from 38,000 to 30,000 tons in 2017 (FAO, 2017). Concerning world imports, the import value of bananas in Lebanon including plantains, fresh or dried was 135,060$ in 2014 with an estimated weight of 198 tons (UN, 2014).
Banana farming in Lebanon had been booming. However, in the recent period, because of some climate-related problems, difficulty in the discharge of production, and spread of high levels of diseases with a continuous rise in pesticides' cost, the quality of banana decreased and banana cultivation isn't competitive in the market as before. This caused the orientation of farmers towards other profitable crops (Avocado, Citrus), but they didn't have experience in that. Thus they moved back to banana culturing, and tried to plant more areas to receive higher productivity. Therefore, the aim of our study was to improve the production and the quality of banana culture. It was based on applying the brown algae, Ascophyllum nodosum (L.), as a growth bio stimulant to confirm its effect on the productivity and quality of bananas. By accomplishing these objectives, we would contribute to higher banana land productivity and encouraging farmers to keep on planting bananas, that can promote the evolution of sustainable banana cultivation in Lebanon.

Material and Methods
This study was carried out during 2018, 2019 on a 130 banana plants (Spanish variety) at Adloun, a coastal village at south Lebanon at 61 km from Beirut with geographical coordination of elevation: 127 m above sea level, latitude: 33.41ºN and longitude: 35.27ºE. The plants were cultivated at spacing 2 m x 3 m. Drip irrigation system was used. All horticultural practices already applied in the orchard, were applied as usually implemented by local farmers.

Planned Experimental Design
The plot was divided into four modalities: Control (Ctrl) by irrigating banana with only water.
Fertigation (F1), the bio stimulant liquid was used through the irrigation system at a dosage of 500 ml per deca (1000m2). The first application was done ten weeks before flower emergence, followed by a four monthly treatments.
Foliar application (F0), the bio stimulant liquid was sprayed on the leaves at a dosage of 200 ml per deca (1000m2). The first application was done ten weeks before flower emergence, followed by a second one 20 days later.
Mixed (M) application where both fertigation and foliar application where used.

Parameters of the Experiment
The studied parameters were the time between flower emergence and harvest, the bunch weight, and the finger weight and dimensions.

Time between flower emergence and harvest
The time (in days) between flower emergence and harvest for each plot was collected by monitoring the dates of flower emergence and harvesting for each sample, and calculating the time in days between them.

Bunch weight
The banana bunch weight (Kg) of each sample was measured using a digital balance after they were harvested at bunch maturation stage, when the fingers reached the full mature stage during the season.

Weight of finger
The finger weight (g) was calculated by dividing the total weight of the bunch on the number of fingers per bunch.

Dimensions of finger
The dimensions of finger (length, diameter and perimeter) were measured in (cm) using a measuring tape.

Statistical Analysis
A statistical analysis was performed using One-way ANOVA in SPSS 24.0 software (IBM Corporation, Armonk, New York, USA) and means were compared using Tukey's B and Tukey HSD tests at 5% level. The results of this study were expressed as means.

Time Between Flower Emergence and Harvest
The average period between flower emergence and harvest for treatments Ctrl, F0, F1 and M was 178.50 days, 126.91 days, 156.83 days and 148.08 days respectively.
According to the obtained results (Table 1), the average period between flowering and harvest in treatments F0 was slightly lower than that in treatments M and F1 respectively where there was a trend close to significant difference. On the other hand, our results showed that there was an interesting trend between the treatment Ctrl and the two treatments, M and F1 at P>0.1 where the average period between flowering and harvest in M and F1 was lower than that of the Ctrl. The only clear significant difference was between treatments F0 and Ctrl in which P=0.005 where the samples in F0 clearly needed less time to be harvested after flowering than that of the Ctrl. A shorter interval between flower emergence and harvest was observed in the trial done in West Africa by Van Iperen where the same product was used on banana plants.
These results agreed with the study done by Roshdy (2014), who showed that the time of flowering was significantly advanced when spraying potassium silicate and seaweed on grand naine banana. These findings were also clarified by Soliman et al. (2000) and Neumann and Zur-Nieden (2001), noting that the advancing effect of silicon and seaweed extract on flowering time might be attributed to their essential role in balancing the ratio between carbohydrates and nitrogen in favor of flowering.

Bunch Weight
The results of the weight of bunch for each plot are shown in Table 1. The average bunch weight for treatments Ctrl, F0, F1 and M was 22.45kg, 27.15 kg, 28.28 kg, and 28.68 kg respectively. Based on the above results (Table 1), the average bunch weight of treatment F0 was slightly lower than that of treatments F1 and M respectively where the difference wasn't significant between them. However, the bunch of samples treated by Van Iperen Stim Pure AA liquid through the 3 types of the mentioned applications were significantly heavier than that of the Ctrl P<0.05.
The improving effect of seaweed extract on the yield and its attributes came to an agreement with those obtained by Roshdy (2014), where the single application of seaweed extracts was significantly accompanied with improving the bunch weight. According to the study of Eman A. Abd el Moniem et al. (2008), the increase in bunch weight was due to the great benefits of algal extract on amending the plants with their requirements from organic and mineral nutrients.
Indeed, our results confirm that in banana crops, foliar spray application is as effective as the application by root drench. Similar increase in weight has been found with other seaweed extracts (Kumari et al., 2011;Zodape et al., 2011), and on other crops sprayed with A. nodosum extract including cucumber, watermelon and pepper (Abdel-Mawgoud et al., 2010).
According to the study of Ali et al. (2015), A. nodosum extract conduct a significant increase by 63% in fruit yields, with 0.5% of A.nodosum extract. This increase in fruit yield was due to the bio-stimulant and bio-fertilisation effects.

Weight of Finger
The results of weight of finger for each plot are shown in Table 1.
The average weight of finger for treatments Ctrl, F0, F1 and M was 115.75 g, 132.03 g, 133.74 g and 135.75 g respectively.
The average weight of finger in Ctrl was slightly lower than that of treatments F0 and F1 which showed approached significant difference between the Ctrl and treatments F0 and F1 in which P was approximately 0.1. On the other side, the average weight of fingers in treatment M was slightly greater than that of treatments F0 and F1 which also showed no significant difference between them in which P>0.05. We can note that the only significant difference appeared between treatments M and Ctrl, where the average weight of finger treated by both fertigation and foliar application (mix) was significantly higher compared with that of the control. Similar results about other crops were reported by Little and Spann (2010), Neily et al. (2010), Ross and Holden, (2010) and Nahed et al. (2011) where the highest amounts of different fruit yield was recorded from A. nodosum extract usage. Based on the study of Norrie J. (2014), the application of Ascophyllum nodosum (L.) under field conditions, showed 8% yield increase in tomato trials, 30% weight gain in pepper trials,25% in bananas,31% in grapes and 7% in apples. Koyama et al. (2012) confirmed that A. nodosum causes the stimulation of vegetative growth in the early stages and promoted reproductive growth in the later stages of crop development, the increased fruit yield is suggested to be partly due to increased translocation of nutrients in the large stems. as.ideasspread.org Agricultural Science Vol. 3, No. 1;2021 In other crops, some authors noticed an increase in fruit weight sprayed with A. nodosum seaweed extract (Abetz andYoung, 1983, Jeannin et al., 1991;Danesh et al., 2012;Bozorgi, 2012) or with extracts from other seaweed species (Khan et al., 2009;Briceno-Dominguez et al., 2014;Satish et al., 2015).

Dimensions of Finger
The dimensions of finger consist of the average length, average diameter and average perimeter.

Average Length of Finger
The results for the average length of finger for each plot are shown in Table 1.
The average length of fingers for treatments Ctrl,M,F1 and F0 was 12.68 cm,13.35 cm,13.37 cm,and 13.51 cm, respectively.
According to Table 1, the average length of fingers in M was slightly lower than that in F1 and F0 which showed no significant difference between them. We can note that the foliar, fertigation and mix (foliar with fertigation) applications of Van Iperen Stim Pure AA liquid were clearly responsible for the increase in the length of finger in which the average length of finger in Ctrl was significantly lower than that of F0, F1 and M at P<0.05.
Similar results about eggplants and different plants were reported by Bozorgi (2012) where the highest fruit length of eggplant was 34.42 cm recorded from 2 g/l of A. nodosum extract applied by foliar spraying application.

Average Diameter of Finger
The results for the average diameter of finger for each plot are shown in Table1. The average diameter for treatments M, F1, Ctrl, and F0 was 3.44 cm, 3.48 cm, 3.48 cm, and 3.49 cm respectively.
The average diameter of finger (Table 1) in treatment M was slightly lower than that of treatments F1, Ctrl and F0 which showed no significant difference between them at P>0.05. Thus, the application of seaweed bio stimulant has no effect on banana average diameter of fingers.

Average Perimeter of Finger
The results for the average perimeter of finger for each plot are shown in Table 1. The average perimeter for treatments Ctrl, M, F1 and F0 was 11.58 cm, 11.63 cm, 11.65 cm, and 12.21 cm respectively. The average perimeter (Table 1) in treatment Ctrl was slightly lower than that of treatments M and F1 which showed no significant difference between them at P>0.05.

Conclusions
Van Iperen's Ascophyllum nodosum (L.) bio stimulant product used clearly showed effects on reducing period between the banana flowering and harvest time, with a significant increase in bunch weight disregarding the method of treatment (foliar, fertigation or mixed application). Even though we noticed a slight increase in fruit length of 5.83%, no significant correlation was established between the increased weight and the dimensions of the fruit. This leads us to conclude that the average increase in finger weight at 15.57% is actually more due to an increase in fruit density rather than fruit size. The application of bio stimulant in the Mediterranean coastal area can be economically justified because of increase of yield and financial returns.