Pruning and foliar nutrition for rejuvenation in passion fruit (Passiflora edulis f.edulis Sims.) for enhancing growth, yield and quality

Abstract

The study entitled “Pruning and foliar nutrition for rejuvenation in passion fruit (Passiflora edulis f. edulis Sims.) for enhancing growth, yield and quality” was conducted in the Department of Fruit Science, College of Agriculture, Vellayani, from 2020 December to 2021 December. Micronutrients and secondary nutrients play a major role in crop production due to their essentiality in plant metabolism and adverse effect that manifest due to their deficiency. The present work was undertaken to assess the effect of pruning and foliar nutrition on growth, yield and quality of passionfruit. The field experiment was laid out in Randomized Block Design (RBD) with 12 treatments and 3 replications. The purple passion fruit variety 134P was selected for the research purpose. Treatments were T1- Removing quarter portion (25%) of current fruiting branch + 19:19:19 @ 1 % , T2 - Removing quarter portion (25%) of current fruiting branch + 19:19:19 @ 1 % + Sampoorna KAU micronutrient mixture @1 % T3 - Removing quarter portion (25%) of current fruiting branch + Water spray (control) T4 – Removing half portion (50%) of current fruiting branch +19:19:19 @ 1 % T5 – Removing half portion (50%) of current fruiting branch +19:19:19 @ 1 + Sampoorna KAU micronutrient mixture @1 % T6 – Removing half portion (50%) of current fruiting branch + Water spray (control) T7- Removing three quarter portion (75%) of current fruiting branch +19:19:19 @ 1 T8 - Removing three quarter portion (75%) of current fruiting branch + 19:19:19 @ 1 + Sampoorna KAU micronutrient mixture @1 % T9 –Removing three quarter portion (75%) of current fruiting branch + Water spray (control) . T10 – No pruning (control) + 19:19:19 @ 1 T11- No pruning (control) + 19:19:19 @ 1 + Sampoorna KAU micronutrient mixture @1 % and T12 –.- No pruning (control) + Water spray (control). Pruning was done in the month of December and foliar nutrient application was done at three times- one month after pruning, at time of flowering and at the time of fruiting. As per Ad hoc recommendation organic manure 112 (10 kg FYM plant-1 ) and NPK (80: 30: 60 g plant-1 year-1 ) were given uniformly to all treatments as soil application. Treatment combination with 75% pruning of current fruiting branch followed by application of 19:19:19@1% + Sampoorna KAU micronutrient mixture at one month after pruning at the time of flowering and at the time of fruiting increased the biometric characters like number of newly emerged branches per vine and reduces the days taken for emergence of new branches. Treatment combination with 50% pruning of current fruiting branch followed by application of 19:19:19@1% + Sampoorna KAU micronutrient mixture at one month after pruning at the time of flowering and at the time of fruiting increased the biometric characters like length of vine, girth of the vine, number of flowers produced per vine per month, total number of flower production and decreased the days taken for first flowering, days taken for first fruiting and flowering to harvest duration. The results revealed that yield characters such as fruit weight, pulp weight, fruit girth, fruit diameter, rind weight, seed weight, rind thickness, number of fruits per vine and total fruit per vine were the highest with the combined application of 50% pruning and foliar nutrition of 19:19:19@1% + Sampoorna KAU micronutrient mixture @1%.100 seed weight was highest for treatment combination of 25% pruning and foliar nutrition of 19:19:19@1% + Sampoorna KAU micronutrient mixture @1% Each character among the qualitative ones examined varied significantly. Combined application of 50% pruning and foliar nutrition of 19:19:19@1% + Sampoorna KAU micronutrient mixture @1% reduced the titrable acidity and recorded maximum TSS, total sugar, reducing sugar, ascorbic acid, carotenoid whereas control plants reported lowest values for these characters. Rind and pulp color also improved in this treatment. Highest non-reducing sugar was recorded in the treatment which received 75% pruning and foliar nutrition of 19:19:19@1% + Sampoorna KAU micronutrient @1% 50% pruning and foliar nutrition of 19:19:19@1% + Sampoorna KAU micronutrient mixture @1% increased the organoleptic qualities like appearance, 113 colour, taste, flavour and overall acceptability. Shelf life of fruits were longer with the same treatment. According to data from the plant analysis, nitrogen, phosphorous, potassium, zinc content was highest with the treatment combination which includes 50% pruning of current fruiting branch and foliar application of 19:19:19 @ 1% + Sampoorna KAU micronutrient mixture @ 1%. Similarly data from fruit analysis showed that nitrogen, phosphorous, potassium, boron and zinc content was highest with the treatment combination which includes 50% pruning of current fruiting branch and foliar application of 19:19:19 @ 1% + Sampoorna KAU micronutrient mixture @ 1% The Brown spot caused by Alternaria passiflorae and scab caused by Cladosporium oxysporum was noticed in the field with less than 1 per cent incidence rate. Also termite infestation was noticed in four plants. The pest and disease incidence were controlled by taking appropriate remedial measures as and when noticed The highest net income and benefit cost ratio was observed with treatment combination which includes removing half portion (50%) of current fruiting branch +19:19:19 @ 1 + Sampoorna KAU micronutrient mixture @1 %. From the above findings, it was concluded that removing half portion (50%) of current fruiting branch and foliar application of 19:19:19 @ 1 % + Sampoorna KAU micronutrient mixture @1 % at 1 month after pruning, at the time of flowering and at the time of fruiting along with the application of organic manure (10 kg FYM plant-1 ) and NPK (80: 30: 60 g plant-1 year-1 ) had increased the growth, yield and quality characteristics of passionfruit and it was economically viable too.