Evaluation of STCR based targeted yield equations of oriental pickling melon (Cucumis melo var. conomon) in Southern laterites

Abstract

The present study entitled “Evaluation of STCR based targeted yield equations of oriental pickling melon (Cucumis melo var. conomon) in southern laterites” was carried out in the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2020-2021. In this study, a randomized block design-based field experiment was conducted to test verify the targeted yield equation developed by STCR 2007 for oriental pickling melon for cultivating it at AEU 8. A farmer’s field was selected in Kalliyoor gram panchayath, Thiruvananthapuram for the field experiment. The variety used in the study was Mudicode. The test experiments included five treatments namely, POP KAU with organic manure management (T1), POP KAU based on soil test (T2), STCR recommendation for a targeted yield of 30 tonnes (T3), STCR recommendation for a targeted yield of 34 tonnes (T4) and STCR recommendation for a targeted yield of 38 tonnes (T5). The targeted yield equation used in the study is; FN = 3.24T – 0.095SN – 0.084ON FP2O5 = 1.64T – 1.332SP – 0.226OP FK2O = 3.16T – 0.068SK – 0.134OK Were, FN, SN and ON is fertilizer nitrogen dose, nitrogen contribution of soil and nitrogen contribution (in kg ha-1) of organic sources respectively. FP2O5, SP and OP are fertilizer phosphorus dose, phosphorus contribution (in kg ha-1) of soil and organic sources respectively. FK2O, SK and OK are fertilizer potassium dose, potassium contribution (in kg ha-1) of soil and organic sources respectively. Here T is the yield targeted in tonnes ha-1. Initial, soil fertility status, nutrient status of organic manures which was used in the field were analysed to calculate the fertilizer dose in T3, T4 and T5. Biometric observations, yield parameters, pre- and post-harvest physicochemical properties of soil and the nutrient content in shoot, root, fruits and dry matter production were recorded to study their influence on yield. Among the treatments, T5 (STCR recommendation for a targeted yield of 38 tonnes) is found to be superior in the biometric and yield observations taken. The 123

targeted yield of 38 tonnes was achieved in this treatment. A maximum fruit length, girth and weight were observed in T5. The major contributing factor for yield increase was the increase in the number of fruits per vine. The vine length and internodal distance were maximum in T5 and days to the appearance of male and female flowers were found to be minimum in T5. There was no significant difference between the treatments while considering the particle density, bulk density, porosity, water holding capacity and porosity. The highest level of primary nutrients was observed in T5 and lowest was observed in T1. The plant nutrient content was analyzed for different plant parts to study the nutrient uptake. The highest uptake of primary nutrients was observed in T5 where the highest yield was also observed. The lowest uptake of nutrients was observed in T1 which yielded the least. This reveals that the fertilizer application can have a direct effect on nutrient uptake and thereby improve the yield of the crop as long as the supplied nutrient is well within the optimum range of crop as suggested in the Mistcherlich equation. The study concluded that the yield targets can be achieved using the targeted yield equations developed for oriental pickling melon in AEU 8. The crop responded positively to higher fertilizer doses in T5 which is reflected in the results obtained while analysing the nutrient content of the crop and the nutrient uptake studies. There was no significant difference between the treatments when the plant secondary and micronutrient content was studied. These nutrients were maintained in a sufficiency range. While considering the economic aspect too, T5 showed superiority over the treatments. The STCR- IPNS based targeted yield equations incorporating recommended organic manures for oriental pickling melon for target up to 38 tonnes per ha can be adopted in AEU 8 as the yield targets can be achieved with optimum use of fertilizers without deterioration of the soil quality and yield. . It also provides serious insights towards improving productivity by optimizing fertilizer dose. This will be useful in upgrading the existing package of practices and doing significant need based research in future which is a vital step towards perfecting the package of practices of KAU.