MSc.

A field experiment was conducted at the Agricultural Research Station, Mannuthy, Thrissur during December 2012 to February 2013 to study the effect of “Fertigation in oriental pickling melon (Cucumis melo var. conomon (L.) Makino) under high density planting” grown in summer rice fallows. Balanced growth, development and yield of oriental pickling melon demand adequate supply of water and nutrients. This research was aimed at increasing the yield and quality of oriental pickling melon by high density planting and fertigation. The crop was planted at a population of 33,333 plants per hectare.
The experiment was laid out in Randomised Block Design (RBD) with three replications. The treatments consisted of combinations of four irrigation levels (50, 75 and 100 % Ep through drip irrigation and farmers practice of pot irrigation) and three fertilizer levels (100, 150 and 200 % RDF). Hence totally it consisted combinations of 12 treatments.
Levels of irrigation significantly influenced the length of vines at harvest, number of leaves per vine, number of branches per vine and LAI. Drip irrigation with 100 per cent Ep recorded the highest values of these parameters. Fertilizer levels also significantly influenced these parameters and the highest values were recorded with 200 per cent RDF.
Interaction between irrigation and fertilizer level was significant on length of vine, number of leaves per vine, number of branches per vine, LAI and shoot dry matter production. In all the growth parameters, I3F3 (100 % Ep with 200 % RDF) recorded significantly the highest length of vine, number of leaves per vine, number of branches per vine, LAI and shoot dry matter production. So there was positive interaction up to 100 per cent Ep through drip irrigation and 200 per cent of fertilizer level. A very high level of irrigation through farmers practice did not respond favourably to increasing doses of fertilizers as under I2 (75 % Ep) and I3 (100 % Ep) in promoting the growth parameters of oriental pickling melon.
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Number of fruits per plant was significantly influenced by the irrigation levels. Maximum number of fruits per plant was recorded at 100 per cent Ep given through drip irrigation and was significantly superior to all other irrigation levels. Fertilizer levels also significantly influenced number of fruits per plant. The highest number of fruits per plant was recorded with 200 per cent RDF.
The fruit characteristics like weight of fruit and volume of fruit were significantly influenced by the levels of irrigation. Maximum weight and volume of fruits were observed at 100 per cent Ep given through drip irrigation and was significantly superior to all other irrigation levels. Fertilizer levels also significantly influenced weight and volume of fruit. The highest average weight of fruit and volume were observed with 200 per cent RDF.
Levels of irrigation significantly influenced the fruit yield. Maximum fruit yield was recorded at the irrigation level of I3 and was significantly superior to all other irrigation levels. Fertilizer levels also significantly influenced fruit yield. Significantly the highest fruit yield was observed with F3.
Interaction between irrigation and fertilizer level was significant on fruit yield. I3F3 recorded significantly the highest fruit yield. So there was positive interaction up to 100 per cent Ep through drip irrigation and 200 per cent of fertilizer level.
Uptake of nitrogen, phosphorus and potassium by the crop depended on the total dry matter production and their contents in fruit and shoot dry matter. In general, their uptake increased significantly up to I3 (100 % Ep) and up to F3 (200 % nutrient level). Since the increase in uptake of nutrients showed linear relationship, higher levels of drip irrigation with more than 100 per cent Ep and nutrient level above 200 per cent are to be tried under high density planting. A high level of irrigation through pot watering resulted in reduced uptake of nutrients.
The favourable interaction between nutrients and water is a well known fact. The study revealed that the favourable interaction between them took place only
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under an ideal moisture level supplemented by drip irrigation with 75 or 100 per cent Ep. Less than an optimum moisture supplementation by drip method with 50 per cent Ep or very high level of moisture supply by a flooding method like pot irrigation did not contribute to favourable interaction between irrigation and nutrients on nutrient uptake.
Field water use efficiency decreased significantly with increase in irrigation levels. From among the treatment combinations, 50 per cent Ep drip irrigation with 200 per cent RDF recorded significantly the highest field water use efficiency and the lowest by pot irrigation.
Levels of irrigation and fertilizer significantly influenced the available nitrogen, phosphorus and potassium in soil at different growth stages of the crop and after harvest. With increasing irrigation level, the nutrient content of soil was decreased at all the stages. Highest available nutrients at all the cropping period and at harvest were recorded with 200 per cent RDF.
Soil moisture content increased with increase in irrigation level from I1 to I4 in all the layers viz. 0-15, 15-30 and 30-60 cm at 15, 30 and 45 DAS. There was no appreciable change in soil chemical properties like pH and EC due to levels of irrigation or fertilizer doses. A slight increase in soil EC was observed with increase in fertilizer level at all the stages of observation.
Among the treatment combinations I3F3 recorded the highest net profit per hectare and was followed by I3F2. Maximum benefit cost ratio was also recorded by I3F3. Most profitable production of irrigated oriental pickling melon under high density planting during summer months was obtained by fertigation with daily drip irrigation at the rate of 100 percent Ep combined with 200 per cent of recommended fertilizer dose. Since the crop response to drip irrigation levels and fertilizer level was linear, it is necessary to further study the effect of fertigation level above 100 per cent Ep and fertilizer level above 200 per cent of recommended dose in oriental pickling melon.