Establishing the Orchard
Total Page:16
File Type:pdf, Size:1020Kb
5 Establishing the Orchard JAMES H. LARUE lanting a fruit orchard is a long-term investment, acreages. On the other hand, a large block of trees of P usually taking 3 years to bear a commercial crop the same variety may not be girdled, thinned, or and then continuing economic production for another harvested within the short time necessary because of 15 to 30 years. Careful planning results in optimum the large numbers of skilled workers required. It is production, high returns, and long tree life. usually best to plant no fewer than 5 acres nor more than 15 to 20 acres of one variety in one block. Site Selection Weather In selecting a site for an orchard, choose a proven When selecting an orchard site, consider weather area for the fruit to be grown. Any attempt to grow a and microclimate effects. The site must not be too new or different fruit crop of high quality and good cold during late winter or early spring when flowers yields in an area that has not been proved increases or young fruits can be damaged by frost. However, the grower's risk. during the dormant season the site must have a period For growing peaches, plums, and nectarines for of cold weather that satisfies the chilling requirement the fresh fruit market, establish the orchard where necessary for normal fruit set and growth in the fruit production is concentrated. Because growing following growing season. Commonly, winter chilling these fruits is both highly technical and specialized, a is measured by calculating the number of hours at or knowledgeable, dependable labor supply is neces below 45°F (7°C) during the dormant season. Most sary; therefore, develop the orchard where skilled peach and nectarine varieties grown in the San labor is available. Crews experienced in pruning, thin Joaquin Valley require 650 to 850 hours of chilling ning, and picking are necessary for each variety of before February 15 for flower buds to break dor fruit grown. Packinghouses must be nearby with mancy and develop normally; leaf buds require slightly capacity to handle large volumes in short periods of more. The chilling requirement for leaf and flower time. Cold storage must be available to cool and store buds of most Japanese plums is 700 to 1,000 hours. fruit between picking and sales. Field personnel from Effective cold hours vary, depending on daytime tem packinghouses, pest control advisors, and other tech peratures and fog cover. For example, a period of nical consultants, such as farm advisors, are essential warm daytime temperatures somewhat offsets the assistants to growers producing fruit crops. effectiveness of previous chilling. Occasionally, areas in the San Joaquin Valley fall short of the chilling Size hours required for most standard varieties. In warmer desert areas, peach plantings are restricted to "low Orchards should be large enough for packinghouse chillers" that require less than 400 hours of chilling. crews or labor contractors to utilize crews efficiently for essential operations. To move a crew several miles Extreme cold. Damage to tree trunks or branches during a busy season for only a few hours' work is by extreme winter cold does not occur in California. usually not economical; thus, packinghouses may be However, in late winter or early spring, when trees reluctant to contract for handling crops from small are in bloom or young fruits are developing, frost 21 damage can and does occur (see chapter 21, Frost water from underground aquifers; other areas utilize Protection). At that time, below-freezing tempera surface water from streams, rivers, or canals. Most tures are almost always the result of temperature orchards in the Central Valley use a combination of inversions rather than invective or cold air mass these two sources. An adequate supply ofwater, avail freezes. Low-lying areas are more susceptible to frost able when needed throughout the growing season, is under temperature inversions because the densest vital. In spite of its availability, the cost of water can cold air tends to accumulate there, Since risk of be a factor if for example, the high power cost of frost damage is greater in low-lying areas, closely pumping from deep wells makes it uneconomical to investigate temperature conditions before planting grow fruit. Water must be free from excessive or an orchard. injurious salts, such as sodium, boron, and chlorides. If water quality is in doubt, particularly well water, Wrnd. Wind is seldom a risk in orchard plantings in have it tested for salt by a conunercial laboratory the San Joaquin Valley, but in other California areas before trees are planted. fruit scarring can cause losses, along with occasional Along with adequate supplies of good-quality limb breakage. Fresh shipping peaches, plums, and irrigation water is the need for the orchard to have nectarines must be cosmetically free of scarring to adequate surface and subsurface drainage. Without prevent their cullage by packers; thus, avoid planting proper drainage of water through the root system where winds are strong enough to cause scarring. and below, trees will lack aeration, develop root or crown diseases, become weakened and nonproduc Hail. Unlike some areas of the world where sununer tive, and even die . Water drainage is poor on some hailstorms occur, California's fruit-growing areas soils, in spite of the many corrective measures avail experience hail only during March and April. Hail can able, and such soils, therefore, are not suitable for destroy bloom, leaves, and young fruit on trees. Flow orchard planting. ers and leaves are sometimes knocked from trees, but the worst damage occurs when young fruit have Past crops, diseases formed and are exposed. Hailstones, even small, soft ones, can severely pit and scar young fruit. Most The crop previously grown on a potential site may hail-scarred fruit must be culled at harvest or in the influence future productivity. Just as field or vege packinghouse. If hail frequently damages fruit, as it table crops may suffer reduced vigor and productive has occasionally in a few local areas in California's ness when the same crop is planted year after year on Central Valley, the risk may not justify planting more the same site, orchards planted on old orchard soil orchards in those particular locations. may react similarly. Trees may show spotty and weak growth, especially during the first few years . To over Heat. Where total heat units are high, as in the come these effects, soil fumigation is necessary before southern SanJoaquin Valley or especially in southern planting where orchards or vineyards have recently California deserts, some varieties will not produce grown. Soil fumigation also helps to rid soil of nema high yields or good quality fruit due to internal heat todes left there from the previous crop. Current damage. Heavy producing varieties often do not yield nematode-resistant rootstocks available for use with as well in these areas because trees tend to produce peaches, plums, and nectarines grown in California excessive vegetative growth at the expense of fruit. resist only one nematode (root knot). However, sev Other varieties tend to "shade out" lower fruitwood eral other species of nematodes may attack these because of early and rapid production of dense cano "resistant" rootstocks and suppress growth, especially pies in the upper half. when trees are young (see chapters 2, Rootstocks, and 19, Nematodes). Water supplies Consider residual soil diseases before planting. If the site has a history of Armillaria (oak root fungus), Because California's fruit-producing regions receive the new orchard will not escape infection, often even no effective rainfall in the growing season, under after soil fumigation. Verticillium wilt, particularly ground or surface water supplies are needed to pro following such previous crops as tomato or cotton, duce crops. Mature orchards use between 3 and 5 may occur for the first few years in the young orchard. acre-feet of irrigation water each growing season, In addition, an orchard site with a history of crown depending upon application efficiency. In some areas rot or crown gall may continue to be diseased into this water is supplied entirely from pumps that draw the next tree planting (see chapter 17, Diseases). 22 Slope The orchard slope and the direction it faces can affect the maturity time of fruit, particularly impor tant in the production of early maturing varieties. An orchard planted on a westward-facing slope or in a location known to produce earlier-maturing fruit is desirable because trees planted on these sites are provided with a microclimate that results in fruit maturing 1 to 4 days ahead of the valley floor. Thus, growers able to pick early and place fruit on the market ahead of other growers frequently receive higher prices. Soil Preparation Peach, plum, and nectarine trees grow and produce best on deep sandy loam soils, free of alkali or salinity Fig. 5.1. Deep ripping an orchard site to break up a hardpan and with good internal drainage. Adequate growth layer. and production can be obtained from trees grown on a wide range of soils, providing the rootstock has been carefully selected. Fruit trees cannot tolerate soils with poor inter Providing drainage nal drainage (whether the result of hardpan, plow pan, or clay layer), which keeps the soil saturated Drain tile , seldom used in California orchards, is with water for extended periods, particularly during sometimes installed to carry off excess water at the the growing season. Groundwater tables must be base of a hill or where there is an abrupt change in well below the root zone for the same reason. slope. Underground water draining from a hill fol lowing winter rains often surfaces where there is a Ripping hardpan, plowpan change in slope at the base of the hill.