Effects of NPK 15 : 15 : 15 Fertilizer on the Growth and Yield of Two Landrace of Snake Tomatoes , ( Trichosanthes cucumerina L . )

DOI: 10.15580/GJAS.2013.9.110913835 The study was conducted to evaluate the effects of NPK 15:15:15 fertilizer on the growth and yield of two landrace of Snake tomatoes, (Trichosanthes cucumerina L..), with the aim to determining the landrace of Trichosanthes cucumerina that best suit the environmental condition of South South ecological zone with special reference to Benin City and also the landrace that responds better to fertilizer application. The experiment was conducted twice in the early and late cropping seasons of 2010. Four fertilizer levels of 0, 80, 160 and 240kg/ha were paired with two landraces of Trichosanthes cucumerina, V1, V2,.The experimental layout was a 4 × 2 factorial experiment in a Randomized Complete Block Design (RCBD). Number of leaves, vine length, and vine girth were taken at 4 and 8 Weeks after Transplanting (WAT), leaf area was determined at mid flowering, while number of days to flowering, fresh weight, dry weight, length of fruits and number of seeds were taken at harvest. The result of the study showed no significant difference in number of days to flowering, aborted flowers, rotted fruits, and leaf area among the landraces, but there was highly significant difference for vine length, vine girth, fruit girth, fruit length, number of seeds, fresh weight, and dry weight between the landraces. NPK 15:15:15 fertilizer levels were significant for all the parameters determined, except for number of leaves at 4 Weeks after Transplanting, and number of days to flowering. Interactions between NPK15:15:15 fertilizer levels and landraces was not significant across the parameters taken at 4 WAT, however it had significant effects on yield data taken. Submitted: 11/09/2013 Accepted: 22/09/2013 Published: 29/09/2013


INTRODUCTION
The Food and Agricultural Organization of the United Nations (FAO), (1998), reported that countries of West and Central Africa sub-regions have a large number of underutilized indigenous edible plant species that are important in the nutrition of the livelihood of rural population.In Africa, scientific studies by Chweya (1996), Adebooye (1996), Adebooye et al (2001), Abutkutsa-onyago (2003) have highlighted the importance of the indigenous edible plants in the nutrition of the rural human population in Africa.These traditional food plants reported by Adebooye (1996) are major sources of nutrients for rural dwellers that cannot afford milk, egg and their products.One of such high premium indigenous food plants is Trichosanthes cucumerina L. commonly known as snake tomato, English tomato and snake gourd.Some other literatures refer to it as Trichosanthes aguina.
Trichosanthes cucmerina is a newly introduced crop of increasing importance in several parts of Africa including Ghana and Nigeria, mainly for the red fruit pulp used as a substitute for the regular tomato sauce, components which provide protection against harmful free radicals and have been strongly associated with reduced risk of chronic diseases such as cardiovascular diseases, cancer, diabetes, Alzheimer disease, cataracts and age related functional decline in addition to other health benefits (Wang et al 1996;Velioglu et al 1998;Cohen et al 2000;Liu et al (2000); Knett et al 2002; Sweeney et al 2002;.Sahlin et al (2004).These positive effects as highlighted above are believed by Lavelli et al (2000) as well as Zhang and Hamauzu, (2004) to be attributable to the anti-oxidants, particularly the carotenoids, flavonoids, lycopene, phenolics and βcarotene.
Earlier studies by Soladoye, (1985) and Adebooye and Olayode (2005) documented that there was little information in the literature on the agronomic practices of T.cucumerina, despite the good nutritional attributes of the crop as highlighted above.It is in consideration of these important nutritional attributes that the cultivation and utilization of the crop should be promoted.In order to promote its cultivation, there is the need to cultivate the different landraces available with the view to knowing the one that best suit this south South ecological zone (Benin City), determine the landraces that respond better to nutrient availability as well as by the cultivation create awareness on the crop to farmers who reside in the community where experiment was carried out (Egor local Government Area).

MATERIALS AND METHODS
The experiment was conducted during 2010 cropping seasons (early and late) at the Teaching and Research Farm of the University of Benin, Benin City, Edo State, Nigeria.The study area fall between latitude 5 0 , 04 N and 6 0 43'' E and longitude 6 0 14" S and 7 0 34 N. with mean rainfall of 2300mm/annum.The seeds of Trichosanthes cucumerina were sourced from the University of Agriculture Abeokuta Ogun state, tagged landrace1 (V1) and Evboneka village in Ovia North East Local Government area of Edo state tagged landrace2 (V2), The latter is the indigenous (local) landrace.
The field was cleared and prepared manually.The land was tilled slightly to loosen up the soil for transplanting.Cow dung manure (cured) was spread evenly all over the entire plot at a flat rate (booster) before transplanting of the seedling, the nursery for the early season experiment was established in March and the late season was established in July 2010.The seeds were planted at a depth of 3cm in a poly bag filled with humus soil weighing 2kg and watered twice daily (morning and evening).Sprouting was observed between 5-7 days after planting until it showed at least 3 distinct leaves.Thereafter, the seedlings were transplanted to the field and planted at a spacing of 1m x 1m on a Plot size of 4m x 2m with a furrow of 1m in between block and plots to prevent border effect.This was followed by thinning to one viable plant per stand, 1 week after transplanting.Trellis was erected on each plot as the crop sown is an annual herbaceous climber.Other agronomic practices carried out include weeding and fertilizer application which was done with the ring method of application six weeks after planting.
Soil samples were collected before and after the experiment in both early and late planting to determine the physico-chemical properties of the soil.
Data was collected on agronomic parameters at 4 and 8 weeks after transplanting.These include vine length, number of leaves, stem girth / vine girth number of days to flowering Four plants were selected and tagged for data collection.Leaf area was measured by meter rule and stem girth by using Vanier caliper.These were carried out at mid-flowering as suggested by Emir, (2009).The yield data were taken during and after harvest.These include fresh fruit weight, dry fruit weight, fruit length, fruit girth and number of seeds per fruit.The fresh fruit weight was determined using a weighing scale, while the fruit dry weight was determined by oven drying the fruits at 105 0 C until a constant weight is reached.The fruit girth and length were determined using Vanier caliper and a meter rule.Harvesting was carried out at full maturity when the fruits started showing signs of color changes from green to orange red, indicating that ripening has started and this was observed at 3 -4 months after transplanting.
The data collected were subjected to analysis of variance and treatment means were compared using the Duncan's Multiple Range Test (DMRT) at 5% probability level using the GENSTAT statistical package.Tables 1 and 2 shows the physico-chemical properties of the soil before planting and after harvest in the early and late planting seasons respectively.Table 3 shows the effects of landraces on the growth parameters measured at 4 weeks after transplanting.Average number of leaves was 7.82cm for landrace1 and 9.88cm for landrace 2, in the early cropping season.Landrace 2 had more number of leaves, and was significantly different from landrace 1 in the early season, although no significant difference was observed at 5% probability level in the late season.

RESULTS
Vine length was 13.58cm and 20.96cm in landrace 1 and 2 respectively with landrace 2 having the longer vine in both seasons, landrace 2 was significantly different from landrace 1 in the early season, but in the late season, the difference observed was not significant at 5% probability level.Vine girth measured was 0.53cm-0.86cmfor both the early and late planting season respectively.Landrace 1 had bigger vine girth and was significantly different from landrace 2 at 5%level of probability.Table 3 and 4 show that there were significant differences between the two landraces used in this study.Landrace 2 produced more leaves and had longer vines.On the other hand, landrace 1 had bigger vine girth.For late season planting, Table 4 shows that landrace 1 flowered early than landrace 2.
There was no significant difference in the flowering pattern for the early season).Leaf area was more in landrace 2 compared to landrace 1 and the differences observed were significant at 5% level of probability.Number of days to flowering was the same for both landraces in the early season as both landrace 1 and 2 took an average of about 80-81 days to get to flowering, however in the late season the result was different as landrace 1 had less number of days to flower (72-73 days) and the difference in the number of days to flowering observed in the late season for both landraces was significant at 5% level of significant Table 6 shows the effects of landraces on yield parameters.The number of aborted flowers was higher in landrace 1 compared to landrace 2. The difference observed in the early season was not significant at 5% level of probability.Fruit girth was more in landrace 1, it was bigger in size compared to ecotype 2 and the difference observed in size was statistically significant at 5% probability level.Landrace 2 was observed to be longer compared to landrace 1 as shown in table 6.The difference observed was significant at 5% probability level.Number of seeds per fruit was more in landrace2 compared to landrace 1, the number of seeds per fruit of landrace 2 ranged between 48-57 while that of landrace 1 ranged between 32-35.The difference observed was statistically significant at 5% probability level.Number of rotted fruits per plot was more in landrace 1 which had an average of about 2 fruits per plot while landrace 2 had an average of 1 fruit per plot, the difference was however not statistically significant in the early season but in the late season the difference was found to be significant.Fresh fruit yield ranged between 3.72-4.11t/ha for landrace 1 and 4.75-5.22t/ha in landrace 2, The difference observed was significant in the early season but in the late season, it was found to be insignificant at 5% probability level.The same trend was observed for the fruit dry yield.Table 7 shows the effect of interaction between landraces and fertilizer level applied on the yield parameters measured.The number of aborted flowers was more in landrace 1 fertilizer level 0 while the least was observed in landrace 2 fertilizer level 3.The differences observed in the various interaction levels were significant at 5% probability level.However, the differences between ecotype 1 fertilizer level 3 and ecotype 2 fertilizer level 3 was not significant at 5% level of probability.The highest fruit length was observed in landrace 2 fertilizer level 3 for both seasons while the least was in landrace1 fertilizer level 0. The differences observed was highly significant at 5% probability level for the early season while the late season crop shows that landrace2 and the various fertilizer levels applied did not differ significantly.The same was also observed in landrace 1 and the various fertilizer levels.Fruit girth was observed to be highest in landrace1 fertilizer level3 while the least was in landrace 2 fertilizer level 0. The differences observed were not significant at 5% level of probability.However landrace1 fertilizer level 3 was significantly different from all other combinations.Number of seeds per fruit was more in landrace 2 fertilizer level 3 for both seasons, though the difference between landrace 2 fertilizer level 3 and landrace 2 fertilizer level 2 was not significant at 5% level of probability.In the early season, the differences observed in landrace 2 and the various fertilizer level applied was not significant at 5% probability level.Number of rotted fruits was observed to be highest in landrace 1 fertilizer 0 while the least was observed in landrace 2 fertilizer 3. The differences observed were significant at 5% level of probability.However, the differences observed in landrace 1 fertilizer level 0 and fertilizer level 1 in the late season was not significant at 5% probability level.Landrace 2 fertilizer level 3 had the highest fruit weight (both for fresh and dry weight) in both early and late seasons, the weight recorded in landrace 2 fertilizer level 1,2 and 3 were not significantly different at 5% level of probability in both season.The same trend was observed in the fruit dry weight.

Number of leaves
The differences observed in the number of leaves showed that landrace 2 was significantly different from landrace 1 which could be adduced to adaptation of landrace 2 to this ecological zone (Benin City) as landrace 2 was locally sourced, hence it is indigenous.Landrace 2 combined favorably with 240kg/ha fertilizer level to bring about highest number of leaves.As the number of leaves in a plant is directly related to the growth and yield of the plant as growth and yield is function of the processes involved in photosynthesis.

Vine length
Landrace 2 had the highest vine length compared to landrace 1 which could be adduced to genetic makeup and also the fact landrace 2 was locally sourced.The interaction shows that landrace 2 combined better with fertilizer applied to efficiently bring about optimum growth compared to landrace 1.

Number of Days to flowering
Landraces 1 and 2 took approximately the same number of days to flower in both the early and late season, though there was little difference in the late cropping season which was significant at 5% level of probability.The result showed that landrace 2 flowered earlier compared to landrace 1, which could be adduced to adaptation and genetic makeup of landrace 2.
Landrace 1 fertilizer level 0 gives the least number of days to flowering.Indicating that the landraces of snake tomato respond to fertilizer application as increase in fertilizer level brings about positive changes in the crop response.

Number of aborted flowers
The observation that landrace 1 had more number of aborted flowers compared to landrace 2 can be adduced to adaptation and the fact that landrace 2 is indigenous and use to the climatic condition of Benin City.
The interaction shows that the least number of aborted flowers was recorded in landrace 2 fertilizer level 3 while the highest was in landrace 1 fertilizer level 0 which gives an indication that fertilizer use efficiency was more efficient in landrace2 compared to landrace 1, because the interaction table showed that landrace 2 fertilizer level 3 was 0.67 and 1.67 for early and late cropping season respectively while landrace 1 fertilizer level 3 was 0.33 and 1.67 respectively.

Fruit length
Fruits of landrace 2 were found to be longer compared to landrace 1, which is likely due to genetic makeup of the plant.

Fruit Girth
Fruit girth of landrace 1 were larger compared to landrace 2. This may most likely be as a result of the genetic constitution of the landrace The interaction between landrace and fertilizer level showed that landrace 1 fertilizer level 3 had the highest fruit diameter of 21.53cm, while the landrace 2 fertilizer level 3 had 18.73cm for the early season while in the late season, landrace 1 fertilizer level 3 had 22.77cm and ecotype 2 fertilizer level 3 had 19.57cm.The diameter of landrace 1 fertilizer level 0 was higher than that of Landrace 2 fertilizer 2 indicating that the diameter of the fruit had a lot to do with the genetic makeup of the landrace while fertilizer only had little influence.

Number of Rotted Fruits
Landrace 2 had the least number of rotted fruits per plot compared to landrace 1.This might be due to adaptation of landrace 2 to the weather condition prevalent in Benin City

Fresh Fruit and Fruit Dry Weight
Landrace 2 had a higher weight compared to landrace1 probably because the former is well adapted to this ecological zone.The differences recorded for both cropping seasons was significant at 5% level of probability.

CONCLUSION AND RECOMMENDATION
In conclusion, landrace 2 performed better in terms of growth and yield except for fruit girth.From all result collated with particular reference to the table of interaction between fertilizer and landrace during the study period, and it responded better to nutrient availability.Hence recommended for the ecological zone (Benin City).It is suggested that further research should be done in the areas of appropriate staking method for better yield and Extension work into bringing the awareness of the importance of the crop to both the rural and urban dwellers.Its improvement will provide alternative for the poverty stricken local Africans who are in constant need of a substitute for the regular tomato, especially during the period of regular tomato scarcity and its attendant high and unaffordable prices .Improving this plant will also help in its conservation and prevent it from the threat of extinction.It is globally acknowledged today that many plants are facing a threat because they have long been neglected in the research and development process.