Good Fruit Grower

December 2012

Issue link:

Contents of this Issue


Page 49 of 79

FIGURE 1 Cropping potential A guide to calculate the cropping potential of a peach or nectarine tree based on tree age, time of crop maturity, and average trunk size. Tree age (years) 2 3 4 4 4 of maturity All maturities All maturities Time Early (May, June) Mid (July, Aug.) Late (Sept., Oct.) 5 and older Early (May, June) 5 and older Mid (July, Aug.) 5 and older Late (Sept., Oct.) Number of fruit per Number of fruit centimeter of trunk per inch of trunk circumference 2.0 2.5 2.5 3.5 4.5 2.0–3.0 3.5–4.0 4.5–5.0 circumference 5.0 6.5 6.5 9.0 11.5 5.0–7.5 9.0–10.0 11.5–12.5 Measure the trunks of 10 trees with a small tape about 200 mm (8 inches) from the ground. These trees are your reference trees and must accurately represent the whole block. Calculate the average circumference and determine the number of fruit per tree by tree age. From this calculation you can work out how many laterals you should leave when you prune your trees in winter, i.e. one, two or three fruit per lateral for early, mid or late-maturing varieties respectively. SOURCE: Bas van den Ende tree casts upon itself limits the production of fruit more than anything else does. Peach and nectarine trees have canopies with dense foliage. It is common to see yellow leaves in midsummer and dead laterals in winter. The condition of the lat- erals in winter shows you how well you have managed sunlight in the previous summer. Summer pruning can alleviate internal shading to a large extent. Having pruned your reference trees, Working with you to help protect your business you can now determine the cropping potential from the average number of lat- erals per tree. Peach and nectarine trees almost always set more fruit than is desired. You need to decide how many fruit you are going to leave per lateral after thinning. This should usually be between one and three fruit per lateral. Leave one fruit per lateral for young trees and early maturing varieties; two fruit per lateral for midseason varieties; and three fruit per lateral for late-maturing varieties. Multi- ply the number of laterals by the number of fruit per lateral to get the number of fruit per tree. If you are not sure what the cropping potential of your young trees is, you can work this out from the average size of the trunks, as shown in Figure 1. When you have determined how many pieces of fruit should be left on each tree after thin- ning, you can work back to how many lat- erals you should leave on each tree in winter. This is called target pruning. Calculating weight Use Figure 2 to calculate the weight of Local service, national resources, customized services. With more than 300 agriculture customers including fruit packing and storage warehouse customers, and over 30 years of agribusiness experience insuring orchards, row crops, hops, and vineyards, Wells Fargo Insurance takes that knowledge and works with the agribusiness community to continually assess risk, identify ways to minimize it, and ensure that your coverage remains the right fi t over time. Wells Fargo Insurance Services USA, Inc. 1430 N. 16th Ave. Yakima, WA 98902 509-248-7460 s Products and services are offered through Wells Fargo Insurance Services USA, Inc. and Wells Fargo Insurance Services of West Virginia, Inc., non-bank insurance agency affiliates of Wells Fargo & Company. Products and services are underwritten by unaffiliated insurance companies except crop and flood insurance, which may be underwritten by an affiliate, Rural Community Insurance Company. Some services require additional fees and may be offered directly through third-party providers. Banking and insurance decisions are made independently and do not influence each other. © 2012 Wells Fargo Insurance Services USA, Inc. All rights reserved. 706 North Chelan Ave. Wenatchee, WA 98801 509-662-5157 fruit per tree, per hectare/acre, or per block. The table shows you the average diameter and weight of peaches and nec- tarines of the two most profitable sizes. Multiply the weight by the number of fruit to calculate cropping potential The following example shows how to calculate the cropping potential of your peach and nectarine trees in winter: A planting of six-year-old white- fleshed peaches maturing in midseason has 1,200 trees per hectare and an average of 85 laterals per tree. Experience tells you that two fruit per lateral gives you pre- mium size. This translates into 170 fruit per tree (85 x 2). The planting has the potential to produce 204,000 peaches per hectare (170 x 1,200). If the average weight of the fruit is 200 grams, the cropping potential is 34 kilograms per tree (200 x 170) or 40,800 kilograms (40.8 tons) per hectare (34 x 1,200). In U.S. measurements, let's assume the planting has 450 trees per acre with an 50 DECEMBER 2012 GOOD FRUIT GROWER FIGURE 2 Peach and nectarine sizes Use this table to calculate the cropping potential of your peach and nectarine trees in winter, as explained in the article. Diameter Diameter Weight Weight (mm) 76 73 69 65 63 27 23 25 21 ⁄8 ⁄4 ⁄8 ⁄2 SOURCE: Bas van den Ende average of 85 laterals per tree and two fruit per lateral. The one-acre planting has the potential to produce 76,500 peaches (170 x 450). If the average weight of the fruit is 7 ounces (3-inch diameter), the cropping potential is 1,190 ounces (170 x 7 ounces), or 74.375 pounds per tree, which translates to 33,468.75 pounds per acre, or 16.7 tons per acre. If you manage your trees and your labor well, and if you have Mother Nature on your side, you stand to pack 90 to 95 percent of the crop. Maintain profitability The best way to ensure that you con- sistently produce large peaches and nec- tarines of high quality is to train and prune your trees well, thin the fruit cor- rectly at "tip-change" when the stone starts to harden, let the leaves and fruit see the sun, irrigate and fertilize well, and harvest the fruit at the correct maturity. Growing of fruit is being buffeted by the winds of change, and like trees in an orchard, orchardists have to bend to sur- vive. The driving force in profitability is high packouts of large fruit. In this day and age, an orchardist who focuses on yield per hectare at the expense of fruit size and quality is seriously mistaken. As you sharpen your shears this winter in readiness to prune your peach and nec- tarine trees, realize that pruning is the most important horticultural practice (excluding irrigation) that an orchardist controls. • Bas Van den Ende is a tree fruit consultant in Australia's Goulburn Valley. 200 7 174 6 160 5.5 143 5 125 4.5 (inches) (grams) (ounces) 3

Articles in this issue

Links on this page

Archives of this issue

view archives of Good Fruit Grower - December 2012