Effect of Organic and Inorganic Fertilizers Amendments on Inflorescence and Flower Morphology and Yield of Coconut ( Cocos nucifera L. )

A study was conducted at the Plant Introduction Center (PIC), Southern Agricultural Center (SARC), Pakistan Agricultural Research Council (PARC), Karachi for the effect of Organic {Neem Seed Powder (NSP) and Gliricidia sepium leaves (GSL)} and Inorganic {(Urea (N), Di-ammonium phosphate (P) and Murait of potash (K), (NPK)} Fertilizers Amendments on Inflorescence and flower Morphology and Yield of Coconut. The experiment consist of eight treatments namely; T 1 (NPK + NSP + GSL), T 2 (NPK+ NSP), T 3 (NPK+ GSL), T 4 (NSP + GSL), T 5 (NPK), T 6 (GSL), T 7 (NSP), T 8 control without treatments. The experiment was laid down as Complete Randomized Block Design replicated three times. The results demonstrated that the number of spikelets with female flowers were significantly high in T 1 to T 7 as compared to T 8 treatment. The 1 st spikelets with number of female flowers (48.97) were significantly (p<0.05) high in T 1 as compared to T 2 , T 3 , T 4 and T 8 . In case of stalk length (38.05 cm) it was significantly (p<0.05) high in T 1 as compared to T 8 . The findings of the study indicated that the number of nuts (99.33) and fruit weight (1490.77 g) were significantly (p<0.05) highest in T 1 as compared to T 3 to T 8 and T 2 to T 8 treatments, respectively. The T 1 treatment also showed better fruit length (25.75 cm), fruit breadth (42.97 cm), husk weight (448.66 g), shell weight (278.11 g), kernel weight (434.22 g) and nut water (188.77 ml) with significant differences in some of the treatments. The application of organic amended with inorganic fertilizers, enhanced the growth and nut production in nutrient deficient soils. It is therefore, recommended that treatment T 1 {NPK+NSP+GSL)}/palm/year was enough to improve the morphological, inflorescence, flower morphology, high nut production, better income to coconut farmers, economical and beneficial for conservation of coconut genetic resources in coastal area of Pakistan.


Introduction
Coconut, (Cocos nucifera L.) is grown in nearly 90 countries existence along the tropical belt. There are about 10 million families rely on coconuts as their main source of food and income. 11.9 million hectares of coconut are grown in the world, eight million hectares, or about 70% is in South East and East Asia (Harries, 1978;Carpio et al., 2005). The coconut is a perennial oil crop, rich in lauric acid and is one of the most important food and cash crop grown in the world. It is widely adapted to the environments and climatic conditions of many producing countries, notably occupying over 20% of the available arable land in most of these countries (Magat, 1996).
The Pakistan coast is an ecologically virgin area and has varied agroecological conditions suitable to grow various crop commodities. The area near the sea coast has a tropical climate and a number of tropical fruit plants are grown including coconut (Laghari and Solangi, 2005). Among the plantation crops of tropical humid areas, coconut occupies an important position in view of the commercial value of its oil on the international market. Coconut tree crop grows well in warm humid weather with an estimated 120 sunshine hours monthly (Murray, 1977). The ideal temperature is around 27 °C with a diurnal variation of 5 °C to 10 °C. Coconut is found in places where the annual precipitation is between 1300 and 2500 mm or above. An average monthly rainfall of 150 mm is ideal for good growth and high nut yield. A prolonged dry spell lasting from five to seven months adversely affects the palms (Rajagopal et al., 1990). Coconut is a cross -pollinated perennial crop and specially propagated through seeds. The coconut seed takes a long time before it attains a stable level of production. Proper selection and planting of good quality seed nuts must be done to ensure a productive plantation (Magat, 1999). Coconut is found to grow well between 20 0 North and South of the equator. Banzon and Velasco, (1982) stated that rainfall has been used as a guide on the suitability of locations for coconut production. The ideal mean rainfall is 150 mm per month or 1800 mm/year. As for the light requirements for coconut crop, the optimum ranges are between 2000 to 2200 hours/ annum (120 hours/month was the minimum) (ICAR, 2004). The coconut palm prefers certain climatic conditions and for its commercial viability climatic factors such as rainfall distribution, altitude, period of drought has to be given serious considerations, whereas the ecological factors are strongly interrelated one finds difficult to classify their influence on the performance of coconuts according to their importance (Karunanayake, 1996).
The coconut tree is known as the tree of life because of its range of environmentally sustainable uses (Foale, 2003). The uses and value of coconut palm to farmers are far greater than Kernel (copra) and oil. The wood or the trunk is used in the building of houses, bridges, cattle sheds and aqueducts (Channel). The root contains drug, recommended against diarrhea. The dry leaves are used for thatching baskets, hats, mats, and curtains. The petioles and midribs of the dry leaves are used for canes, brush, needles, pins, and fishhooks. The flowers opened inflorescences when cut, yield a liquid called toddy from which palm wine is prepared. About 70 percent of the female flowers a coconut palm produced are shed or lost. These buttons contain 10 to 12 percent tannins. The coconut water contains growth promoting substance, some ascorbic acid, protein, and carbohydrates. The fibrous husk yields important fiber called coir. Coir dust is used as insulating materials and for the reclamation of low-lying areas (Nathanael, 1961;Von-Uexhull, 1971). Balakrishna, (1975) studied that all the inorganic and organic fertilizers mixture treatments have consistent and significant effects on the yield. The non responsiveness to fertilization of seedlings in the early nursery stages could be due to the already sufficient levels of nutrients available while they were still in the endosperm stage. Inorganic and organic fertilizers, nevertheless, differ in the availability of mineral plant nutrient they contain. Nutrients in inorganic fertilizers are directly available to plant roots provided water or soil moisture ionized the fertilizers, whereas the nutrients of organic materials, particularly organic N are low availability.
The identification of specific characters in coconut which may contribute to its increased yield, adaptation to specific environment and production of products preferred by the consumers should be prioritized (Foale, 1992). Studies on coconut for morphological descriptions such as color, size and shape of the fruit, robustness of the trunk, and crown size carried out (Child, 1964;Ohler, 1984). Relation between leaf length and yield in coconut indicated that a palm with longer leaves and more leaflets per leaf would show higher yield (Abeywardena, 1976). Jayalekshmy and Rangasamy (2002) studied characters included both vegetative, inflorescence and fruit characters. Ratnambal et al., (2005) noticed that the popular cultivars known across the world (West Coast Tall, Tiptur Tall (both from India), West African Tall, Philippines Ordinary Tall and Sri Lanka Tall) have many fruit characters in common. In other words, in most of the coconut growing countries, the cultivators considered the fruit type of these cultivars as the ideal. The indigenous collections also exhibited enormous variability. The correlation among the fruit characters was attributed to three causative factor's, the first one related to weight measurements, second is for nut-constituents and third for the husk. The important characters that cause divergence as obtained from the canonical analysis were weight of fruit, length of fruit, volume of cavity, weight of shell and percentage of husk to fruit weight. The aim of the present research is to investigate the effect of organic and inorganic amendments on morphological diversity and yield of adult coconut along with comparative performance of different organic and inorganic soil amendments on the coconut nut production and to find out the suitable and economical dose of fertilizers for coconut palm.

Selection of experimental site
A four years (2007 to 2010) study was conducted at the Plant Introduction Center (PIC), Southern Agricultural Research Center (SARC), Pakistan Agricultural Research Council (PARC), Karachi. Karachi is situated on the coast along the Arabian Sea (Latitude 24° 50`-25° 15` North and Longitude 65° 51`-67° 40` East, altitude 26 ft above sea level) of Pakistan. The climate of Karachi is subtropical maritime desert (Chaudhry, 1961). Climatically, the study area falls under humid type, and forms a part of the coastal area. The sensitivity to temperature not only limits coconut in terms of the latitude (27 o N and 27 o S) but within these ranges the altitude higher than 600 m above sea level is some what the maximum limit for optimum coconut growth. The average temperature 33-35 °C and Yearly relative humidity was 80% of the past six years (2005 to 2010) (PMD, 2011). The physiochemical properties of the soil was analyzed prior to the trial and the result showed mean amount of 0.78 EC (ds/m), 34.00% CaCO 3 , 0.34 MO%,0.012ppm N, 12.72ppm P, 79.0ppm K . The soil was sandy loam alkaline with pH 8.47.

Inflorescence and flower Morphology
The experiment was conducted to study the effect of organic and inorganic amendments on the adult palms at PIC, Karachi. For each treatment, three coconut palms were selected randomly from the experimental plots and each treatment was carried out in three replicates. Thus, in the whole study 72 adult coconut palms were characterized by the method of IPGRI (International Plant Genetic Resource Institute), (1995) and Santos, (2001).
The inflorescence length, number of spikelets, number of spikelets with female flowers, 1 st spikelet with number of female flowers and stalk length were measured. The stalk length is the distance between the point where the bunch is attached to the palm and the base of the first spikelet. The coconut fruit set and developed to maturity in about 12 months and yield is usually estimated in terms of the number of nuts produced per palm. The nut production of coconut (No. of nuts), fruit weight, fruit length, fruit breadth, husk weight, shell weight, kernel (meat) weight and quantity of nut water was recorded as described by Santos, (2001) and BI (Bioversity International), (2007).

Organic and Inorganic Fertilizers
The detail of amendments included Urea, Di-ammonium phosphate and Muriate of potash (NPK) in combination with Neem seed powder (NSP) and Gliricidia sepium leaves (GSL) at different levels is given below:-

Statistical Analysis
The experiments of organic and inorganic amendments were laid out in a Completely Randomized Block Design (CRBD). All the data were statistically analyzed by the analysis of variance (ANOVA) (Gomez and Gomez, 1984) and Duncan Multiple Range Test (DMRT) (Duncan, 1955 andZar, 2010).

Results
The effects of organic and inorganic amendments on inflorescence length and total number of spikelets were non significant in all the treatments observed (Table 1). The results of the present investigations also revealed that the number of spikelets with female flowers were significantly (p<0.05) high in T 1 to T 7 as compared to T 8 treatment. The 1 st spikelet with number of female flowers were significantly (p<0.05) high in T 1 as compared to T 2 , T 3 , T 4 and T 8 , whereas non significant differences were recorded in T 2 to T 8 . In case of stalk length, it was significantly (p<0.05) high in T 1 as compared to T 8 . Moreover, no significant differences were found in T 2 to T 8 treatments.
The nut production of coconut was affected significantly (p<0.05) by the application of organic and inorganic amendments ( Table 2). The findings of the study indicated that the number of nuts were significantly (p<0.05) higher in T 1 and T 2 as compared to rest of the treatments, whereas T 3 , T 4 and T 5 treatments showed significantly (p<0.05) high number of nuts as compared to T 6 , T 7 and T 8 treatments. Similarly, the number of nuts were significantly (p<0.05) high in T 6 as compared to T 7 and T 8 treatments. The fruit weight was significantly (p<0.05) high in T 1 as compared to rest of the treatments. The treatments T 2 to T 7 showed significantly (p<0.05) high yield as compared to T 8 . The fruit length was significantly (p<0.05) high in T 1 as compared to T 4 , whereas non significant results were found in T 2 to T 8 treatments. The fruit breadth was significantly (p<0.05) high in T 1 as compared to T 4 , T 6 and T 7 . Moreover, non significant differences were found in T 2 to T 8 treatments. The present study also reveals that husk weight of coconut was significantly (p<0.05) high in T 1 , T 3 and T 4 as compared to T 6 , T 7 and T 8 . Similarly, the husk weight was found significantly (p<0.05) high in T 2 as compared to T 7 . Moreover, non significant differences were found in T 1 to T 5 treatments. The husk weight was also found non significant in T 5 to T 8 treatments.
The effect of organic and inorganic amendments on shell weight was significantly (p<0.05) high (278.11 g) in T 1 as compared to T 7 and T 8 treatments whereas, no significant difference was recorded in T 1 to T 6 (Table 3). Moreover, non significant differences were found in T 2 to T 8 treatments. The results indicated that, the kernel weight was significantly (p<0.05) high in T 1 and T 2 as compared to T 6 to T 8 treatments, whereas non significant differences were found in T 3 to T 8 treatments.
The present study also reveals that the quantity of nut water (188.77 ml) was significantly (p<0.05) high in T 1 as compared to rest of the treatments. Moreover, non significant    Table 3. Effects of organic and inorganic amendments on shell weight, kernel weight and quantity of nut water of coconut (Cocos nucifera L.) differences were found in T 2 to T 6 treatments. The quantity of nut water was also significantly (p<0.05) high in T 6 as compared to T 8 treatment, whereas, non significant results were found in T 7 and T 8 treatments.

Discussion
The effects of organic and inorganic amendments on inflorescence length and total number of spikelets were non significant in all the treatments. The number of spikelets with female flowers were significantly (p<0.05) high in T 1 to T 7 as compared to T 8 treatment. The 1 st spikelet with number of female flowers were significantly (p<0.05) high in T 1 as compared to T 2 , T 3 , T 4 and T 8 , whereas non significant differences were recorded in T 2 to T 8 . In case of stalk length, it was significantly (p<0.05) high in T 1 as compared to T 8 . Moreover, no significant differences were found in T 2 to T 8 treatments. The results confirmed with the findings of Emmanual, (2002) and Uddin, (2003) who reported moderate diversity in vegetative characters of coconut populations. Selection based on these morphological characters might be immense value in the coconut improvement program.
The findings of the study indicated that the number of nuts were significantly (p<0.05) higher in T 1 and T 2 as compared to rest of the treatments, whereas T 3 , T 4 and T 5 treatments showed significantly (p<0.05) high number of nuts as compared to T 6 , T 7 and T 8 treatments. Kalpana et al., (2006) also studied the effect of two integrated nutrients treatments, 50% organics + inorganics 50% and 100% organics on yield, soil and plant nutrient status in coconut based cropping system and observed that the highest nut yields/palm/year (113) was recorded in the first treatment as compared to only 89 nuts/palm/year in second treatment. According to Longanathan (1977) investigated that the fertilizer is the most important and costly input to enhance crop yield. There is no doubt that fertilizers play a very active role in increasing crop yield. Systematic manuring with balanced fertilizer mixtures is an essential practice in the cultivation of coconut. The present study also reveals that the quantity of nut water (188.77 ml) was significantly (p<0.05) high in T 1 as compared to rest of the treatments.  found that the application of the recommended rats of inorganic fertilizers and goat manure during the early stage of coconut growth significantly improved the vegetative growth characters of palms. Kalpana et al., (2006) studied the effect of two integrated nutrients treatments, 50% organics + inorganics 50% and 100% organics on yield, soil and plant nutrient status in coconut based cropping system. The results showed that the highest nut yields/palm/year (113) was recorded in the first treatment as compared to only 89 nuts/palm/year in second (control) treatment. Devasenapathy et al., (1996) studied that the application of sodium chloride at 1kg/palm/year along with the recommended dose of NPK had significantly influenced the growth, nut characteristic and nut yield. Marimuthu et al., (2001) reported that application of 50 kg farm yard manure, along with the recommendation dose of NPK, recorded the highest N, P and K contents in soil and leaf, with 47% high nut yield compared to the control.

Conclusion
The study demonstrated that the treatments T 1 {Nitrogen, Phosphorus and Muriate of potash (NPK) + Neem seed powder (NSP) + Gliricidia sepium leaves (GSL)} and T 2 (NPK+ NSP) significantly (p<0.05) increased most of the morphological characters (number of spikelets with female flowers, 1 st spikelets with number of female flowers, stalk length, number of nuts, fruit characters and quantity of nut water).
In this investigation, it is concluded that the application of organic amended with inorganic fertilizers, enhanced the growth and nut production in nutrient deficient soils in growing sites of coastal areas. It is therefore, recommended that treatment T 1 {NPK (1.0:0.5:1.0kg) + NSP (10.0kg) + GSL (20.0kg)} palm/year was enough to improve the Inflorescence and flower Morphology high nut production, better income to coconut farmers, economical in coastal area of Pakistan.