Avocado Production in Asia and the Pacific - United Nations in ...

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4. ESTABLISHMENT OF ORCHARDS If an avocado plantation is to be established in a relatively new area, the varieties to be selected for planting should belong to both A and B groups and their flowering must overlap. The proportion of A and B group varieties can be 1:1 or 2:1. Avocado is planted out to a distance of 6 to 12 metres depending on the vigour of variety and its growth habit. For varieties having a spreading type of growth, like Fuerte, a wider spacing should be given. In areas prone to excess water, they should be planted on mounds as avocados cannot withstand waterlogging. In Sikkim, a planting distance of 10 x 10 metres on hills slopes (on half-moon terraces) is preferred and planting is done in June- July. Pits of 90 x 90 centimetres are dug during February-March, and filled with farmyard manure and top soil (1:1 ratio) before planting. In Coorg, a region of Karnataka state, they have been planted also as one of the mixed crops in a primarily coffee-based cropping system. 5. CARE AND MANAGEMENT OF ORCHARDS Pruning is rarely practised except with upright varieties such as Pollock. In spreading varieties like Fuerte, branches are thinned and shortened. Heavy pruning has been found to promote excessive vegetative growth, consequently reducing the yield. Sprinkler irrigation has been reported to improve the fruit size and oil percentage; also, it advances harvesting time. Irrigation at intervals of three to four weeks during the dry months is beneficial to avocado. To avoid moisture stress during winter season, mulching with dry grass/dry leaves is desirable. Flooding is undesirable as it promotes root rot incidence. Avocados need heavy manuring, and application of nitrogen has been found to be most essential. In general, young avocado trees should receive N, P 2 O 5 and K 2 O in a proportion of 1:1:1 and older trees in the proportion of 2:1:2. At a pH of above 7, iron deficiency symptoms may appear, which may be corrected by applying iron chelate at the rate of 35 g/tree. Various micronutrients (Fe, Zn, B) have profound influences on tree growth, nutrient uptake and yield of avocado. Integrated nutrient management with inorganic fertilizer, supplemented by organic manuring, is advocated for avocado. In Sikkim, the soil is deficient in nitrogen, zinc and boron. Application of urea in two split doses, in March/April and September/October (just before and after the onset of the monsoon) is recommended. Foliar application of zinc sulphate (0.5 per cent) may be undertaken in April-May, and other fertilizers applied in soil during March-April. A tentative fertilizer schedule recommended for Sikkim (Upadhyay and Srivastava, 1996) is shown in Table 2. 27
Table 2. Fertilizer Schedule for Avocado in Sikkim Manure/ Fertilizer (kg/tree) Farmyard manure Urea Time of Age of Plants (year) Application 1 st 2 nd 3 rd 4 th 5 th 6 th 7 th & above February/March - 10 20 30 40 50 60 March/April 0.10 0.15 0.20 0.25 0.30 0.35 0.40-0.60 September/October 0.10 0.15 0.20 0.25 0.30 0.35 0.40-0.60 Muriate of March/April 0.10 0.20 0.30 0.40 0.50 0.60 0.70-0.80 potash Bone-meal March/April 0.30 0.40 0.50 0.60 0.70 0.80 1.00-1.50 Among insect pests, scales, mealy bugs and mites are the important ones, and may be controlled by suitable insecticides. Fruit spot disease caused by Colletotrichum gleosporioides results in shedding of young fruits. Fruits often become deformed. The infection may remain latent in some fruits. Another strain of the same fungus causes leaf spot. Accelerated softening of fruits caused by Fusarium solani and F. sambucinum has been reported. The Fuerte cultivar is reported to be more susceptible to anthracnose (Glomerella cingulata var. minor) and stem-end rot (Dothiorella aromatica) from fruit set till harvest. The time of infection has been found to vary with the seasons and is related to rainfall. In addition, Cercospora sport (Cercospora purpurea) and scab (Sphaceloma perseae) have been found to attack both leaves and fruits also. The most serious disease of avocado is the root rot caused by Phytophthora cinnamoni, leading to death of plant. The disease situation is aggravated by ill drained and waterlogged conditions. Metalaxyl (Ridomil) mixed with soil before planting or applied as a soil drench controls root rot at least for four months after treatment. 6. FRUIT HARVESTING AND YIELDS Avocado plants raised from seeds start bearing five to six years after planting. Mature fruits of purple varieties change their colour from purple to maroon, whereas fruits of green varieties become greenish-yellow. Fruits are ready for harvest when the colour of seed coat within the fruit changes from yellowish white to dark brown. Mature fruits ripen six to ten days after harvesting. The fruits remain hard as long as they stay on the trees, softening only after harvest. The yield ranges from about 100 to 500 fruits per tree. In Sikkim, specifically, on average 300-400 fruits can be harvested from 10-15 years old trees. In Sikkim, fruits of Purple variety are harvested during July, and for Green variety September-October is the usual harvesting time. In Tamil Nadu, July-August is the peak harvest time. The yield performance of avocado, both in tropical southern India and humid sub-tropical northeastern India is highly satisfactory. 28
Page 2 and 3: RAP PUBLICATION: 2000/09 AVOCADO PR
Page 4 and 5: TABLE OF CONTENTS Page FOREWORD ii
Page 6 and 7: INTRODUCTORY REMARKS Minas K. Papad
Page 8 and 9: WELCOME ADDRESS Prem Nath * It is a
Page 10 and 11: AVOCADO PRODUCTION IN AUSTRALIA Ant
Page 12 and 13: cultivar of the Guatemalan race and
Page 14 and 15: is good practice to cover the one s
Page 16 and 17: Australia. As it migrates into orch
Page 18 and 19: 8. POTENTIAL FOR AVOCADO PRODUCTION
Page 20 and 21: AVOCADO PRODUCTION IN CHINA Liu Kan
Page 22 and 23: Spacing The spacing varies with cli
Page 24 and 25: attacking young trees in Hainan. It
Page 26 and 27: 8. POTENTIAL FOR AVOCADO PRODUCTION
Page 28 and 29: will have a great potential market
Page 30 and 31: 2. PRESENT SITUATION OF AVOCADO CUL
Page 34 and 35: 7. POST-HARVEST HANDLING, STORAGE A
Page 36 and 37: AVOCADO PRODUCTION IN INDONESIA Sri
Page 38 and 39: 3. PRODUCTION OF PLANTING MATERIAL
Page 40 and 41: 9. GOVERNMENT POLICIES AND PLANS FO
Page 42 and 43: The avocado trees grown are all see
Page 44 and 45: AVOCADO PRODUCTION IN THE PHILIPPIN
Page 46 and 47: 227: The fruit is bottlenecked and
Page 48 and 49: Weeding and mulching Mulching of av
Page 50 and 51: Firstly, the avocado can be found g
Page 52 and 53: Table 2. Research Projects/Studies
Page 54 and 55: AVOCADO PRODUCTION IN SRI LANKA Mos
Page 56 and 57: 3. PRODUCTION OF PLANTING MATERIAL
Page 58 and 59: compost and cattle manure is the we
Page 60 and 61: 9. CONSTRAINTS IN AVOCADO PRODUCTIO
Page 62 and 63: AVOCADO PRODUCTION IN THAILAND Chal
Page 64 and 65: 4.3 Planting Planting is carried ou
Page 66 and 67: Table 1. Fruit Characteristics of S
Page 68 and 69: Royal Project Foundation helps avoc
Page 70 and 71: AVOCADO PRODUCTION IN VIETNAM Nguye
Page 72 and 73: Though avocado was introduced into
Page 74 and 75: Table 3. Rate of Fertilizer Use in
Page 76 and 77: without grading. To avoid partly th

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