Standardization of propagation and performance assessment of mechanical harvesters in clove (Syzigium aromaticum (L) Merr. & Perry)

Abstract

The present investigation entitled “Standardization of propagation and performance assessment of mechanical harvesters in clove (Syzigium aromaticum (L) Merr. & Perry).” was carried out in the Department of Plantation Crops and Spices, College of Agriculture, Vellayani during the period 2020-2022 with the objective of standardization of seed treatment for improved seed germination, grafting method and performance assessment of mechanical harvesters in clove. Clove is commercially propagated by seeds but the viability of the clove seed is less and germination is generally poor. Hence, to improve the seed germination rate an experiment was conducted using seven seed pretreatments and were compared with the control. Freshly harvested fully matured clove fruits are collected and subjected to different pretreatments viz. IAA 20 ppm (T1), GA3 50 ppm (T2), GA3 100ppm (T3), PGPR Mix Ⅰ 5 per cent formulation (T4), PGPR Mix II 5 per cent formulation (T5), Piriformospora indica 105cfu/ml (T6), carbendazim 0.1% (T7) and control (T8). These pretreated seeds were sown in protrays and kept under two growth condition viz. polyhouse with temperature and humidity control (C1) and polyhouse without temperature and humidity control (C2). T1 C1 recorded the highest germination and survival percentage of 90% at 3MAS, basal shoot girth of 0.42cm, mean germination time of 33.15 days, mean germination rate of 3.02 x10-2day-1, coefficient of velocity of germination of 3.21x10-2, germination rate index of 26.82 %/day, germination index of 1477.30, root shoot ratio of 0.50 and allometric index of 0.99. At the same time T2C1 recorded the highest number of leaves of 7, leaf length of 6.90cm, leaf breadth of 2.76cm, leaf area of 12.37cm2, shoot length of 15.51cm, fresh shoot weight of 2.28g, dry shoot weight of 0.48g, root length of 13.85cm, fresh root weight of 0.43g, dry shoot weight of 0.17g, seedling vigour index Ⅰ of 2598.26 and seedling vigour index Ⅱ of 55.02. Even though seed treatment of IAA 20ppm along with growth condition in Polyhouse with temperature and humidity control was identified as ideal for better seed germination, seed treatment of GA3 50ppm along with growth condition in polyhouse with temperature and humidity control showed superior seedling growth characters. 138 Clove is commercially propagated by seed and development of any vegetative method of propagation can be helpful in reducing the height of the crop, early yield and true to type. The percentage of success to propagate clove by vegetative method was less. The production of phenol content may be one reason for this. Hence methods to overcome the phenol content was tried along with different grafting methods. The treatments included approach grafting without antioxidant treatment (T1), approach grafting with antioxidant treatment (T2), soft wood grating without antioxidant treatment (T3), soft wood grafting with antioxidant treatment (T4), epicotyl grafting without antioxidant treatment (T5), epicotyl grafting with antioxidant treatment (T6), patch budding without antioxidant treatment (T7), patch budding with antioxidant treatment (T8) kept under two growth conditions viz. polyhouse with temperature and humidity control (C1), polyhouse without temperature and humidity control (C2). At the end of 6 months, T2C1 recorded higher number of leaves (13.30), length of leaves (4.51) and breadth of leaves (2.46). Hence approach grafting with antioxidant treatment with growth condition of Polyhouse with temperature and humidity control is found to be best for the vegetative propagation of clove Performance assessment of mechanical harvesters and manual harvesting in clove were analysed. Mechanical harvesters such as VIMAL 2 stage tree pole pruner (T1), Wolf-Garten Bypass steel Telescopic pruner (T2), SHAFIRE Steel Blade Hand Pruner (T3) and Manual harvesting(T4) were compared. Manual harvesting was found to be more economically feasible, taking only less time for postharvest cleaning operation with significantly lower operator fatigue and high field coverage.