Introduction Improvement in grape production Natural variation Plant breeding Growing your own Calculations...

Transcription

1 Grape production Part 4: Grape improvement Introduction... 2 Improvement in grape production... 3 Demand for vine material...3 Improved management practices...4 Natural variation New varieties...10 Variation...11 Plant breeding Genetics...18 New vines...23 Genetic engineering...25 Regulatory bodies...26 Vine improvement schemes...28 Growing your own Calculations Suggested answers Exercises Part Part 4: Grape improvement 1

2 Introduction Introduction The success of the Australian grape industry is due to the accomplishments of many people. The marketing of grape produce, technological developments and improvements in grapevine management have all contributed. The Cooperative Research Centre for Viticulture has produced a video and a booklet, The Australian grape advantage which outlines these achievements. In this part you will focus on: improvements in the management of vines new and improved grape varieties methods of plant breeding. In Australia, there are several institutions currently researching various ways to improve grape industries and management practices. This research aims to improve grapevine performance under Australian conditions. New and improved grape varieties are being developed. Research stations are producing grapevines that: are resistant to disease; produce higher yields; produce grapes of better quality; are more resistant to rain damage; are grown on rootstocks that absorb nutrients more efficiently; use improved cultural practices. As well as investigating the results of some of the plant breeding being done by researchers you will be carrying out your own plant trials. This will allow you to work first hand with the sort of statistics researchers use. To see results, you will need to continue this activity for at least three months. This part contributes towards an understanding of Outcomes H1.1 and H2.1 from the Agriculture Stage 6 HSC Course. The syllabus can be found on the Board of Studies, NSW website at 2 Grape production

3 Improvement in grape production Improvement in grape production Growers are always aiming to improve productivity. Research in viticulture is supporting producers by investigating management practices, breeding new varieties and improving existing ones. Demand for vine material The demand for vine material (cuttings) increased significantly in the nineteen nineties. The table below shows increased sales of vine materials in the period from 1991 to There are many implications for vine research when demand and therefore sales increase. Type of material Increase in sales (%) table grape 51.5 multipurpose 89.5 white wine grape red wine grape rootstocks total cuttings (1991) total cuttings (1995) 3.4 million 15 million The demand for vine material has increased from 1991 to (Source: Andrew delaine. Executive Officer. Australian Vine Improvement Association. Presented at Charles Sturt University, Wagga Wagga on 24th September 1996.) You can see that demand for vine material has greatly increased. This is in response to an increased consumer demand resulting from some very successful marketing both here and overseas. Part 4: Grape improvement 3

4 As well as socioeconomic forces, the production of grapes is also under pressure from changing soil conditions, the influence of the environment and the spread of disease and pests. Improved management practices may result in increased productivity. Improved management practices Vineyard managers aim to increase grape production and decrease the cost of inputs to the system. This results in increased productivity (with a corresponding increase in profits). 1 Identify the inputs of a grape growing system. Refer to the previous notes to list at least four inputs. 2 Briefly describe how at least two of these inputs can be reduced. Check your answers. Pruning techniques Pruning is one of the vineyard operations that requires a high labour input. A reduction in pruning would significantly reduce the cost of labour. The Grape and Wine Research and Development Corporation has developed a technique of minimal pruning. Listen again to the interview with Ian MacRae again to hear about the outcomes of minimal pruning at Miramar in Mudgee. What has Ian MacRae found out about minimal pruning? Check your answers. 4 Grape production

5 Irrigation management Grapes and other plants increase their water use as the season progresses. This is shown in the table below which lists data from orchards in the Granite Belt in Queensland. Growth stage Trees (L/tree/wk) Grapes (L/vine/wk) budburst early December Water use of trees and vines throughout the growing season. Source: Crew PS. DPI Note. Drip irrigation scheduling for Granite Belt Orchards. (1984). Queensland Department of Primary Industries. The State of Queensland. 1 Describe the trend in water use through the growing season, in Queensland, in both trees and vines. 2 Identify two factors that would influence water use by trees and vines. Check your answers. Work is currently being done to investigate water management strategies for vines. Growers need to know when to water, how much, which irrigation system is most efficient and how to estimate soil moisture levels. Management practices for different climates are currently being investigated, for example vines in warm irrigated areas have a reduced nutrient uptake. In Victoria, research is being carried out on the efficiency of mineral uptake by different rootstocks at the CSIRO. Part 4: Grape improvement 5

6 Irrigators are under pressure from environmental groups to become more efficient water users. Why do you think this is so? Discuss your ideas with a friend, family member, another student or your teacher. Use the questions below as the basis for a discussion. Should water restrictions be tightened, for example quotas, timing? Should irrigators pay more for their water? Should irrigators be levied to cover the costs of reversing environmental degradation due to overwatering? Do you think irrigators are using too much water? Do you think growing drought resistant varieties would be a good strategy? Give reasons. Disease management Researchers are investigating various methods to control phylloxera. Soil types and plant stress levels are being mapped by remote sensing methods. This data is analysed to detect phylloxera before the symptoms can be seen. The extent of the damage and rate of spread of phylloxera can then be estimated. The chemical Enzone was developed as a preventative insecticide spray. It was successful in the laboratory but results varied in the field. Management strategies such as making sure that vine material, equipment and machinery are clean before they come into a vineyard should slow the spread of phylloxera. Resistant rootstocks tolerate the pests feeding on their roots. Rootstocks that are suited to the climates of grapegrowing areas are being developed. Briefly describe the steps you would take if you were a grape producer and phylloxera was known to have spread into your district. Check your answer. 6 Grape production

7 Viruses There are many viruses that infect grapevines. Some infected vines show no symptoms. Some diseases require the presence of more than one virus. New viruses are being identified in other parts of the world. The vectors (disease carriers) are not known for many viruses. Australian researchers are working on a fast and accurate way to detect viruses. There is also work being done on producing disease resistant varieties. For example, researchers are hoping to produce vines that are resistant to the viruses that cause leafroll disease. Since mildews are also a major problem, research work is being carried out to produce resistant varieties C days new virus free vine grows in culture Heat treatment and tissue culture are methods used to remove viruses from vines. Vines are grown in temperatures too high for viruses to survive. The growing tips are then removed and propagated in tissue culture. Dried fruit production and processing The CSIRO, in conjunction with the Dried Fruit Research and Development Corporation, is currently working on many aspects of dried vine fruit production. This is a growing export industry and improvements in production and processing will benefit our overseas reputation. Current research is focusing on reducing chemical use to dry and fumigate fruit; and on producing varieties that are resistant to the effects of rain and disease. Part 4: Grape improvement 7

8 The diagram following shows the steps involved in the production and processing of dried fruit. This process is changing as new technologies are being developed. a) spray with alkaline emulsion b) dry in sun 1 Harvesting 2 Drying stalks air water a) shaken to separate stalks b) removal of grit, etc c) washing and drying 3 Processing Figure 4.3: The production and processing of dried vine fruit. In the dried fruit industry grapes are picked at specific Brix values. They are then laid on racks, one bunch deep, to dry. Premium quality fruit is golden yellow. Grapes must be dried quickly otherwise they turn dark brown. Generally, the darker the fruit, the lower the price. Fruit is sprayed with an oil emulsion to speed up the drying process. This is a mixture of an alkali and a vegetable oil. Recent research at the CSIRO has shown that the drying oil can be reduced by about half and still produce fruit with a good colour. Drying time is reduced as well as costs and residues. Fruit is dried to a moisture level of 13%. Then it is processed to remove stalks, foreign matter, before being fumigated and packaged. Dried fruit is fumigated with methyl bromide to get rid of pests. This chemical is toxic to humans. In Australia, and overseas, research is being carried out to find an alternative. Other, safer, methods are being assessed eg spraying with carbon dioxide. oil fumigant d) oil coating e) fumigation e) packaging Dried fruit production and processing. 8 Grape production

9 1 Identify the inputs for dried fruit production and processing. 2 Explain how the findings of current research projects can reduce the inputs and therefore improve efficiency of dried fruit production. Check your answers. Summary Vineyard managers are aiming to improve productivity. Grape researchers are finding new ways to manage grapevines. Improved production methods will increase grape productivity. In the next section you will find out how new and improved grape varieties are being developed to better suit Australian conditions. Vineyard (S. Annetts) Part 4: Grape improvement 9

10 Natural variation Natural variation The climates of Australian grapegrowing regions are generally quite different from those in Europe. Australia s climate is more similar to North Africa. The growing conditions influence the quality and quantity of grapes produced, therefore, we cannot expect to produce wines like those of France and Spain. Breeding grapes to suit Australian conditions will produce excellent grapes but the wine will be different to those produced in Europe. New varieties Just recently a new Australian wine has reached the market. This light, red wine is made from black Tarango grapes. These were bred from crossing Touriga, a Portuguese variety, and Sultana. Taminga is another wine grape developed at the CSIRO s Division of Horticulture at Merbein in Victoria. In addition, the breeding program has developed a drying grape Carina; Marroo Seedless, a table grape; and Merbein Seedless, a multipurpose grape. What is your favourite table grape? What do you like about this grape variety? Think about features such as the season available, colour, flavour, seeds, size and firmness. How could it be improved? (List the features.) 10 Grape production

11 Access an interactive version of Natural variation using this link. Resume with this material on page 18: Plant breeding. Variation Grapevines don t necessarily reach their genetic potential. For example, a vine may have genes for high yield, large berries and high sugar levels. However, the grapes produced by this vine may be small and sour. What could go wrong? Identify three reasons why you think a vine might not reach its genetic potential. Check your answers. The way environmental factors influence the performance of the vine is called genotype X interaction. This is seen as variations in the performance of vines of the same genotypes in different environments. Plant breeding is all about identifying variations, making selections and breeding to produce commercial cultivars. Looking at variations in traits Many characteristics of plants are influenced by several genes. This means that these traits will vary enormously though most individuals will be close to the mean. A few will measure much higher; some will be much lower. Traits vary in populations and between populations. There are also individual differences between plants. Traits that vary in plants include height, yield and leaf length. Part 4: Grape improvement 11

12 Wheat yield example Yield is an important trait that varies a lot. It is influenced by a number of factors both environmental and genetic. The University of Sydney has a wheat breeding station at Narrabri, NSW. The mean yields of wheat are shown in the following graph. Wheat (S.Annetts) The distribution of wheat yields. Mean yields of wheat from the University of Sydney s wheat breeding program at Narrabri in NSW. Reproduced by the permission of Oxford University Press Australia 1988 from, The Scientific Basis of Modern Agriculture by Campbell KO and Bowyer JW (eds), ISBN Wheat yields are influenced by many genes. As you can see, yield varies widely across sample populations. The distribution of yields, when graphed, are very close to a bell-shaped curve. This is known as a normal distribution. a) b) c) A normal distribution is graphed as a bell-shaped curve. Most of the population is clustered around the mean. Graphs a, b and c all show normal distributions. The population shown in graph a is clustered around the central tendency (the mean). On the other hand the population in graph c is widely spread around the mean. 12 Grape production

13 Bean weight example Seven hundred and twelve beans were weighed in a study. Since there were a large number of measurements, the weights were grouped into classes. For example, you can see from the table that there were 179 beans that weighed between 4.5 and 5.0 x 10-1 g. The number of beans, for example 179, is the frequency for this class. The % frequency is the proportion of beans in a particular group. That is the number of beans in the group is divided by the sample number and multiplied by 100%. frequency % frequency = sample number = % = 25.14% 100% Class (X 10-1 g) (measurements between) Frequency (how many measurements) % Frequency (proportion of measurements) Distribution of bean weight. Source: Harder R, Schumacher W, Firbas F and von Denffer D. (1967). Strasburger s Textbook of Botany. Longmans, Green and Co Ltd. London. England. Part 4: Grape improvement 13

14 Use the experimental data in the previous table to revise graphing, analysing and interpreting data. 1 Draw a histogram to show the distribution of bean weights % frequency Weight of beans (10-1g) Variation in weight of beans. 2 The estimated mean bean weight is 4.53 X 10-1 g. Mark this on your graph. 3 Describe the distribution of the weight of beans in this sample population. Does this graph resemble a bell-shaped curve (a normal distribution)? Check your answers. 14 Grape production

15 Analysing data Recommendations can be made to producers from data collected by researchers, but this can only be done if the data is analysed accurately, for example by calculating arithmetic means and standard deviations. The average value of the sample is called the arithmetic mean. You have calculated this several times in your course already. The mean is the highest point on the normal distribution curve. Since the data varies so much we need to measure its spread. This is done by calculating the standard deviation. It indicates how much the data is dispersed about the mean. For example, a large standard deviation indicates that the data is very spread out. This would be the case for the data graphed on page 12 (graph c). A small standard deviation means that the data is clustered around the mean; there are few measurements that differ greatly. Graph a in the figure on page 12 would have a small standard deviation. HELP: Do you need help to calculate an arithmetic mean and a standard deviation using a calculator or computer? If so, turn to the Calculations section for step by step instructions. Grapevine leaves example Most variables in agricultural experiments show a normal distribution. Let s see if this is true for the length of grapevine leaves. The length of 102 Muscat grapevine leaves was measured. The results are recorded below. 11.2, 12.8, 13.6, 7.4, 13.2, 14.3, 15.3, 15.3, 11.1, 14.7, 12.5, 16.3, 13.8, 13.9, 11.9, 13.0, 13.2, 13.4, 11.9, 15.8, 12.4, 17.8, 10.2, 15.4, 17.2, 17.1, 9.2, 7.5, 7.4, 8.2, 14.3, 17.1, 12.7, 12.5, 15.9, 16.2, 16.8, 11.2, 12.5, 10.9, 9.8, 15.4, 10.5, 11.1, 12.5, 14.0, 11.3, 15, 14.8, 18.1, 13.8, 19.1, 18.4, 17.3, 11.4, 11.6, 8.3, 10.8, 10.9, 13.8, 14.2, 11.7, 13.3, 12.4, 12.2, 17.1, 10.6, 10.2, 18.6, 14.6, 13.3, 16.2, 15.3, 13.4, 14.3, 14.4, 9.1, 12.3, 14.8, 9.8, 11.3, 11.4, 13.6, 12.6, 8.3, 13.0, 13.4, 13.9, 11.0, 12.1, 13.2, 9.2, 10.0, 10.2, 16.0, 9.3, 8.8, 12.7, 13.4, 8.9, 13.5, 8.8 Raw data. Measurements (in millimetres) of Muscat grapevine leaves. Part 4: Grape improvement 15

16 1 What is the average length of a leaf on the Muscat grapevine? Calculate the arithmetic mean for the data above. 2 Calculating the standard deviation will allow you to more accurately analyse (or describe) the data. Outline what this value indicates about the experimental data. _ 3 Grouping the data will make it easier to handle. Complete the following frequency table. Class (measurements between) Frequency (how many measurements) % Frequency (proportion of measurements) /102 X 100 = Grape production

17 4 Graph the data as a histogram Distribution of leaf length on a Muscat grapevine. 5 Describe the distribution of leaf length on the Muscat grapevine. Is this normal? (Is the curve bell-shaped?) Check your answers. Now it s your turn. Complete Exercise 4.1: Variation in nature. Summary Many traits vary in nature. They are spread as a normal distribution. Data from the measurement of plant traits can be analysed by calculating the arithmetic mean and the standard deviation. Next you will be investigating plant breeding techniques. Part 4: Grape improvement 17

18 Plant breeding Plant breeding Ever since plants have been cultivated, growers have been improving them. Plant breeding programs can range from simply growing plants from the seeds of outstanding individuals to more sophisticated genetic engineering techniques. You will be looking at a range of strategies. Access an interactive version of Plant breeding using this link. Resume with this material on page 30: Growing your own. Genetics The genetic potential of a grapevine is due to its genotype or genetic makeup. The genes present determine the traits (or characteristics) expressed by the organism. A study of how these traits are inherited is called genetics. plant cell plant vacuole cell wall nucleus cell membrane genes chromosome Genes code information in organisms. They are located along chromosomes in the nucleus of cells. Plant breeding relies on the identification of desirable characteristics, for example large grapes, low tannin levels, resistance to splitting after rain. These observable traits are called a plant s phenotype. Observable traits may include grape colour, leaf shape, vine vigour, bunch size and weight 18 Grape production

19 to mention only a few. Each trait or characteristic is determined by a single gene or several genes present in the organism s cells. Heredity or environment? Vines of the same variety often have different phenotypes. That is, they have a similar genotype but they look and perform differently. This may be due to environmental factors. It is difficult to determine whether a plant is growing well because it is genetically superior or whether it is simply growing in a good spot. List the features a trial plot should have so that you could determine the influence of genotype and environment. Check your answer. New and improved plants Plant breeders are aiming to produce plants that: yield more are easier to process taste better are more nutritious have improved economic value are better suited to the environment have better keeping qualities are resistant to disease have greater colour variations. There are a variety of methods plant breeders use to produce new and improved plants. This may depend on how the plants normally reproduce. That is, whether they are a self pollinating species, for example wheat, rice; or cross pollinating species, for example lucerne, maize. Some plants are more easily propagated vegetatively, for example grapevines, potatoes. Part 4: Grape improvement 19

20 Mutations Changes in a plant s genotype are called mutations. They are a source of plant differences in nature; and are the raw material of traditional plant breeding. However, these changes are unpredictable and slow in nature. beneficial result? deleterious plant with superior phenotype eg higher yield, more vigorous, good colour plant with inferior phenotype eg tough skins, susceptible to disease, lower yield Mutations change plants in the field. Superior plants are used in breeding programs. Self pollinating species Pollen is transferred from the anther to the stigma of the same flower. This produces seeds after fertilisation occurs. The offspring are pure bred. It can be referred to as inbreeding. 20 Grape production

21 1 self pollinating plants are crossed male parent X female parent P 1 2 superior offsrping selected hybrid offspring F 1 3 repeated self pollination and selection 4 replicated trials carried ou t at different locations pure line progeny F 6 commercial cultivar A simplified outline of a breeding program for a self pollinating species like wheat. Outline a breeding program for a self pollinating species. Check your answer. Hybrids produced by crossing two inbred plants often show increased height, vigour, fertility and yield. This is known as hybrid vigour. Cross pollinating species Pollen from the anther of one plant is transferred to the stigma of a different plant. This is called outbreeding or cross pollination. Improvement in a population of plants can be achieved by the following steps. First, superior plants are selected from the population. These are then randomly cross pollinated, for example by insects. Progeny are Part 4: Grape improvement 21

22 selected on identified characteristics and are intercrossed. The population is improved by repeated selection and intercrossing. Vegetative reproduction Plants may be reproduced by budding, grafting, cuttings or tissue culture. This is also known as cloning. Cloning is the normal method of reproducing grapevines cuttings are grafted onto rootstocks or planted in the ground. Striking cuttings from pruned vines is shown below. This is a relatively inexpensive way to increase vine numbers. Once a superior plant has been selected it can be rapidly reproduced in large numbers. The new plants have the same genetic material as the parent vine. pruned vine stem cuttings 1 Prune vines stem cutting stem cutting well drained potting mix rooting powder 2 Apply rooting powder 3 Strike cutting in pots Propagating vines vegetatively from cuttings. 22 Grape production

23 New vines To improve on a population of grapevines, new plants can be produced by crossbreeding. This produces a mix or blend of characteristics from both parent plants. This is called hybridisation. 1 collect pollen from stamen 2 transfer pollen to stigma male parent female parent 3 collect seeds and plant 4 select 'best' genotypes 5 clone as commercial cultivar Cross pollination is a technique used to produce new varieties of grapevines. This produces hybrid plants. The superior genotypes may then be cloned. Outline how hybrid grapevines are produced. Check your answer. Part 4: Grape improvement 23

24 Producing commercial cultivars a) clones in different areas are selected for trialling over 5 10 years area 1 area 2 area 3 area 4 yields recorded and compared b) 2 5 top performing clones selected and compared more thoroughly research station virus indexed c) selected clones released through vine improvement scheme high yielding quality virus free vines A generalised breeding program for improved vine material. The previous diagram shows the steps involved in producing grapevine cultivars for sale to nurseries and growers. Plants are compared then commercial clones are selected. Once suitable plants are selected, possibly from a crossbreeding program, the clones are trialled in large replicated plots in various environments. Outline the method used to produce commercial cultivars. Check your answers. 24 Grape production

25 Genetic engineering Traditional plant breeding takes a long time and results are not guaranteed. More recently scientists have been manipulating the genes of plants, animals and micro-organisms. This is commonly known as genetic engineering. Genetically engineered plants have the potential to increase food production and reduce chemical use. Genetic engineering aims to produce high yielding varieties of plants that: are resistant to disease, insect attack and/or herbicides are more water efficient can tolerate high salt levels. Biotechnology There are a variety of products that are produced using biological processes (biotechnology). Developing improved plants by genetic engineering is one area of biotechnology. Biotechnology brewing fermenting genetic engineering beer vinegar wine drugs medicines improved plants Biotechnology uses natural processes to produce many different products. Plants are now being bred by changing the codes (the gene sequence) in cells. Genes are made out of a chemical called deoxyribonucleic acid. This is widely known as DNA. Part 4: Grape improvement 25

26 Transgenic species Gene transfers can be between closely related species or unrelated species, for example from a bacterium to a grapevine (transgenic species). Beneficial genes are identified, for example a gene which produces resistance to mildew. Once the gene is identified it can be moved from one cell to another. DNA DNA 1 Identify gene 2 Isolate gene 3 Insert into in bacterial cell plant cell The genes responsible for specific functions in cells are identified, isolated and inserted into other cells. Regulatory bodies Manipulating and transferring genes has the potential for harmful consequences. This is why groups were formed to monitor genetic research. The Genetic Manipulation Advisory Committee (GMAC) oversees work in scientific laboratories, breeding organisms in culture and releasing new species into the environment. Centres that carry out genetic research have internal committees which supervise laboratory work and report to the GMAC. These regulatory bodies make sure that the genetic research undertaken is safe and ethical. Read the information that follows. Form a discussion group with friends, teacher, other students and/or family members. 1 Improved plants can occur naturally or by genetic manipulation. Genes change naturally (mutate). Some of these changes result in a plant that is better able to survive and reproduce. Genetic engineering also changes gene sequences but there is the potential for a much larger number of these. Does it matter that new plants are created in the laboratory rather than by nature? Discuss. 26 Grape production

27 2 Genetic engineering can target specific genes. These are then removed from one cell and placed in another s DNA. Undesirable traits cannot be transferred as well since the sequence is known before it is manipulated. How accurate do you think this statement is? 3 Modern biotechnology produces many new plant varieties such as Stanley seedless grapes. Many more improvements are being researched such as bloat free lucerne. The advantages far outweigh any disadvantages. Discuss. 4 There may be many more new crop varieties produced by genetic engineering than by traditional breeding programs in the future. Is this a good advance for agriculture? Why? Why not? 5 The loss of biodiversity (the natural variety of living things) is one environmental issue that many people are concerned about. There are fewer varieties of agricultural plants being farmed now than in the past. Should we be relying more on sustaining natural biodiversity rather than creating our own varieties? Is modern agriculture contributing to this problem? Is it more important that we feed millions of people? What do you think? Part 4: Grape improvement 27

28 Vine improvement schemes Each state has its own vine improvement scheme. Winemakers, growers and researchers are represented on committees. The state groups have established and maintained plantings of rootstocks and vine material. These are distributed to nurseries and growers on a commercial basis. The groups involved in vine improvement in Australia are shown on the diagram that follows. Australian Vine Improvement Association consists of: Representatives from Vine Improvement Groups Observers from Industry Groups WA Vine Improvement Association CSIRO Department of Primary Industry & Fisheries NT NSW Agriculture Queensland Fruit & Vegetable Growers Grape and Wine Research & Development Corporation SA Vine Improvement Committee Australian Dried Fruit Association Tasmanian Vine Improvement Association Australian Tablegrape Growers Association MIA Vine Improvement Society Winegrape Growers Council of Australia Victorian and Murray Valley Vine Improvement Association Australian Council of Viticulture The Australian Vine Improvement Association is made up of state representatives and observers from various industry bodies. 28 Grape production

29 Protection of new varieties The Plant Variety Rights Act of 1987 was introduced to protect the commercial rights of plant breeders. In 1994, the Plant Breeders Rights Act replaced this earlier Act. These laws ensure that the commercial rights of breeders of new varieties of plants, fungus and algae are protected. Plant breeders have exclusive rights to sell, import, export and reproduce the protected plant. This right continues for 20 years (or 25 years in the case of trees and vines). New varieties registered include: Jonared an early maturing tree with large red apples Chieftain a high yielding barley with good malting properties Herald a vigorous medic that has aphid resistance Blondie early flowering hardy waxflower with a long vase life. There are many more registered plant varieties developed for agricultural and horticultural purposes. These plants are selected on criteria such as yield, flower colour, resistance to disease and shelf life. Read the statements below. Do you agree or disagree with them? Discuss the implications of Plant Breeders Rights on agriculture with friends, family and people involved in agriculture. 1 New plant varieties are developed from plants in nature. Individuals and organisations should be able to profit from their work since they are contributing to agricultural productivity. 2 The cost of new plants can be high because of the exclusive commercial rights of the organisation or company. There should be some sort of regulation regarding the cost to the consumer. Complete Exercise 4.2: Improving on nature. You will be outlining plant breeding programs as well as recording your thoughts and feelings on some of the safety and ethical issues surrounding genetically engineered plants. Summary Plant breeding programs begin by selecting plants with superior characteristics. In traditional breeding programs commercial cultivars are produced by a series of crossing and selections. New cultivars can be produced by genetic engineering. The commercial rights of plant breeders are protected by legislation. Part 4: Grape improvement 29

30 Growing your own Growing your own Overseas markets are interested in the exotic flowers of Australia. There are a large number of Australian wildflowers that are currently being produced, including proteas and kangaroos paws. The market may, in the future, demand a larger range of diverse flowers. In this part you will design and carry out an experiment to identify the best conditions to grow a local native plant. Assume that a commercial market for these plants has already been identified. You will be able to make recommendations to anyone that wants to grow these plants on a commercial scale. In times of drought, farmers are reminded of the important role of native pasture grasses in animal production and in controlling erosion. A major difficulty faced by graziers wanting to establish native pastures is lack of suitable seed. Native flora cannot be harvested from the bush to supply these markets; they need to be produced on farms. In order to do this producers need to know the soil and climatic conditions that best suit these plants. Growers can then modify these factors to maintain or increase productivity. Once the optimum environmental conditions for producing a plant are identified, then the plant type is often modified. For example, plants are bred with new flower colours, better feed value, pods resistant to shattering or drought tolerance. Read through the Exercise 4.3: Growing a native plant. Next draft your ideas. Make sure you are clear on why you are doing this experiment and how it can be done. Talk to your teacher about your investigation. It is critical that your experimental design will give you valid results. Check your design with your teacher before you start. 30 Grape production

31 1 Collect seeds of native plants The first thing you need to do is collect the raw material for your experiment. Make sure you have permission to collect seeds in the area or on a property. The seeds can be from grasses, legumes or small flowering plants. You will need between fifty and a hundred seeds collected from plants at random to eliminate bias in the experiment. Describe the plants you collected seeds from, for example colour of leaves, habit (upright, climbing, spreading, prostrate) and habitat (grassland, forest floor, rock crevice, river bank). You could record some of the features of the plant with a photograph. Collect a reference specimen from the population if you can. This can be pressed and dried for later reference. A native poppy. The leaves are mid green, it is upright and can be found in grasslands. The average height of the plants is 23 cm. Grows in heavy soils with a high proportion of clay. Soils are hard setting and crack when dry. There are, on average, three flowers per plant. The flowers are pink red with a black centre. The population is scattered over a large area. These plants can be found in the southern Riverina. Part 4: Grape improvement 31

32 2 Prepare the seedbeds You will need to germinate your seeds before you begin the trial. You can use large pots or trays, for example styrofoam fruit boxes. You should replicate the control and the treatment/s at least three times. Therefore, you will need at least six similar containers to conduct a replicated trial. Make sure your soil or potting mix has a good tilth. That is, it is not lumpy, or too fine; it holds water and nutrients, but doesn t get waterlogged. If your soil is too heavy you may need to mix it with sand, compost or peat moss. Fill the pots or trays with the soil and water. Don t forget to randomly select three pots for the control and three for the experimental group. Label the pots or trays as C = control group, E = experimental group, for example. C C E E E or or C CE C E C E C CE E C C C E Replicated trial. Plots are chosen randomly to eliminate bias. Good experimental design is essential in obtaining reliable data. 3 Check the environment Temperature is very important to germinating seeds and growing plants. Choose a warm place such as a greenhouse, verandah or porch. Make sure that there is adequate light for plant growth. Record the elements of the environment that are critical to your trial, for example temperature, humidity and light. This may give you an indication of how these factors have affected your trial plants. Record measurements in the results table for the entire three months. 32 Grape production

33 4 Plant your seeds Make holes or furrows in the soil. Plant the same number of seeds in each pot or tray. Cover the seeds with a fine layer of soil or sand. The smaller the seeds the thinner the layer of soil, for example small seeds can be covered with about 2 mm or soil; large seeds about 10 mm. Space seeds out to reduce competition. Ensure soil is moist enough because seeds need to take up water to trigger germination. Not sure what to do? If so, call your teacher, ask your friends, neighbours, family or local nursery person for advice. This is not easy to do on your own. Try using a reference book or looking up advice on the internet. 5 Set up your trial This is a controlled experiment. This means that you will keep all variables constant except one, the experimental variable. Possible variables include: soil characteristics plant nutrition temperature light levels humidity Record your experimental design. daylength rainfall sowing date fertiliser type. 6 The next four weeks Make sure that your seeds are kept moist over the next four weeks. The time taken for germination varies a lot for seeds, from a week to months. Remember to continue to monitor the environment. Ensure there is enough light. If seed trays look a bit mouldy or smell damp then you may need to move them to a better ventilated area with more light. All your seeds may not have germinated at the end of the four weeks. This doesn t mean that they won t, they may just be slower or the conditions may not suit them (for example some seeds need to be burnt, some need to experience very cold conditions). Thin the seedlings, if necessary, but make sure there are equal numbers of plants in each pot or tray. Part 4: Grape improvement 33

34 7 Make observations throughout the trial Objective measurements are useful in making accurate comparisons, however, visual assessment of plants is also useful when monitoring plant growth. For example, leaf colour, signs of disease, strength of stems. These observations may indicate lack (or excess) of nutrients, water or the presence of disease organisms. Don t forget to reduce competition from weeds (pull them out). Record your visual assessment of the plants. 8 Measure your plants At the end of the trial, make your final measurements. These can be dry matter, yield, leaf length, plant height. Record your plant measurements. 9 Analyse results Calculate the mean and standard deviation for your results. Graph your data. Record and graph your statistics. 10 Interpret your results From your results, draw conclusions and make recommendations. Record your conclusions and recommendations. Complete Exercise 4.3: Growing a native plant. In conclusion The grape industry in Australia is a success story. From your knowledge of grape production in Australia what do you think has contributed to this? Did you think of: marketing the produce both here and overseas to increase demand increasing the quality of the produce continuing improvement in vine material and production methods. 34 Grape production

35 Successful industries go beyond on farm production. A demand must exist before farmers go into production. Marketing is a key factor. Consumers are demanding that food and fibre be produced in an environmentally friendly manner. Farmers must produce these commodities efficiently using the most appropriate management practices. Research organisations and extension officers have a role to play in keeping producers up to date with the latest developments in science and technology. Many people are working together to produce high quality agricultural products in an environmentally sustainable manner. Of course, farmers need to be economically sustainable also. Part 4: Grape improvement 35

36 Calculations Calculations Statistical data is more easily analysed using a calculator or computer. The instructions for the calculations are based on: Casio scientific calculator ClarisWorks spreadsheet for Mac users. Statistics by calculator 1 AC ON Turn calculator on. MODE 3 χσ η 1 Switch calculator to statistics mode. SD can be seen in the display window. 3 SHIFT AC ON Clear previous data in the memory. 4 eg. 5 M+ Enters a set of measurements into memory. Enter each number, then press M+. eg. 8 X 5 M+ When entering frequency scores, enter the number, then multiply by the frequency, then press M+. 5 SHIFT M M+ Deletes a score that was entered wrongly. DATA DEL 6 Kout 3 χσ η 1 η To get the number of scores entered. 36 Grape production

37 7 SHIFT 1 χ Calculates the arithmetic mean or average of the scores. 8 SHIFT 3 χσ η 1 η Calculates the standard deviation for the sample. Statistics by computer 1 Enter the data. Enter each score in a cell, press return key. 2 Calculate arithmetic mean. Select cell for mean value. Choose Paste Function from Edit menu. Part 4: Grape improvement 37

38 3 Enter function formula. Select AVERAGE when dialog box appears. 4 Enter mean. Select scores used to calculate the mean. Press enter key. 5 Enter standard deviation formula. Select cell where standard deviation is to be entered. Select STDEV from Paste Function dialog box. 6 Calculate standard deviation. Select scores that are to be used to calculate the standard deviation. Press the enter key. 38 Grape production

39 Suggested answers Suggested answers Improved management practices 1 Inputs include: vines (cuttings), labour, machinery, water, chemicals (fertiliser, herbicide, fungicide, fumigant). 2 Labour can be reduced by reducing pruning or by the use of mechanical harvesters. Chemical use can be reduced by integrated pest management strategies, for example cultivation to remove weeds. Water use can be reduced, for example by using more efficient watering systems. Pruning techniques Minimal pruning works well for some vines, for example Cabernet Sauvignon in Mudgee. Minimal pruning achieves the same aims as intensive canopy management. That is, there is a large surface area of leaves exposed to the sun, a minimum leaf thickness and since there are a large number of buds, there are a high number of bunches with small berries. Irrigation management 1 The amount of water used by plants increases through the season. 2 Increasing temperature and plant growth (leaves, roots) increases the amount of water taken up by plants. Disease management Make an accurate assessment of the damage that might occur. Calculate the financial viability of replanting the vineyard with resistant rootstocks. How much profit is there in the vineyard? How long before the vines are productive? How much will the rootstocks cost? In addition, reduce the chances of phylloxera by ensuring equipment, machinery and vine material is clean and free of soil when moving in and out of the farm. Part 4: Grape improvement 39

40 Dried fruit production and processing 1 Inputs include grapes, labour, machinery, oil emulsion, water, fumigant (methyl bromide or carbon dioxide), packaging. 2 This research can benefit dried grape production by: making the drying process quicker (better fruit colour); using fewer chemicals; using safer chemicals (carbon dioxide instead of methyl bromide); using smaller amounts of chemicals. Other outcomes would include new varieties (for example higher yielding; disease, rain damage and drought resistant), improved rootstocks (for example salt tolerant), better canopy and irrigation management techniques and minimal pruning. Variation The soil may not suit the vine, for example prone to waterlogging and low in nitrogen. The seasonal conditions may not have been suitable, for example heavy frosts and a drier than usual growing season. The climate may not be suitable, for example too cold during the spring and summer months for the grapes to ripen. There could have been high levels of pest damage, for example disease causing viruses, bacteria or fungi or the vine may have been overrun with weeds. Bean weight example 30 estimated mean Weight of beans (10-1 g) 3 Most of the beans weigh close to the mean. Very few beans weigh a lot more or a lot less. It resembles a bell shaped curve. 40 Grape production

41 Grapevine leaves example 1 Arithmetic mean = Standard deviation = This indicates that most of the leaves are close to the average length. Class (measurements between) Frequency (how many measurements) % Frequency (proportion of measurements) Distribution of leaf length on a Muscat grapevine. Part 4: Grape improvement 41

42 5 There are only a few leaves that are much longer or much shorter than the average. Most of the leaves are close to the average. The distribution of the leaf length is normal. It resembles a bell shape. Heredity or environment? Replication of trials ie. duplicate the experimental set up for the control and the treatment group (3 6 times). Make quantitative eg. yield, ph; and qualitative measurements eg. flavour, colour and wine quality. Ensuring the trials are uniform by controlling the variables eg. several clones of each different plant should be grown in the same soil type, same irrigation system, same amount of water, same aspect, same amount and type of fertiliser and same pruning techniques. Samples should be representative of the population; samples should be chosen at random to eliminate bias. Trials would need to be carried out over long periods, for example ten years to get more valid results due to climatic influences. Another method would be to grow the plants in controlled atmosphere, for example in a glasshouse. However, the plants would also need to be grown in field conditions to reflect the real situation. Yields in a glasshouse may differ quite a lot to those of a paddock. Self pollinating species In a simple breeding program two plants with desirable characteristics are cross bred. This is the P 1 (first parents) generation. Suitable offspring are selected and are then allowed to self pollinate for several generations. These offspring are the F 1 (first filial) generation. The selected progeny (descendants) are by now nearly pure bred. The surviving plants are grown in replicated trials in different locations. High performing plants are chosen as commercial cultivars. New vines Hybrid grapevine are produced by cross pollinating two plants with desirable characteristics. The resulting seeds are collected and planted. The top performing vines grown from these seeds are selected and cloned to produce commercial cultivars. These plants are hybrids. 42 Grape production

43 Producing commercial cultivars Large numbers of top performing clones are selected and trialled in various grapegrowing areas. The yields of each clone are recorded and compared for the length of the trial (up to ten years). The top performing clones are selected for more extensive trialling. The performance of selected clones is compared more thoroughly (yield and grape quality) at a research station. The best clones are virus indexed to ensure they are not infected by disease causing viruses. The best vines are released through the vine improvement scheme. They are then reproduced in large numbers for nurseries and growers. These commercial cultivars are high yielding, high quality and virus free vines. Part 4: Grape improvement 43

44 Exercises Part 4 Exercises Part 4 Exercises 4.1 to 4.3 Name: Exercise 4.1: Variation in nature It s hard to believe that many variations in nature form a normal distribution. In this activity you will be collecting and analysing data from your own area. 1 Go outside and find a large number of plants (of the same type) that you can measure. You can choose to measure their height, leaf length, leaf width, number of seeds, number of flowers; any characteristic that varies naturally. a) Name of the plant. b) Part being measured. 2 Record your measurements. The larger the number, the more likely your sample is representative of the whole population. 3 Analyse your data. Complete the table below. 44 Grape production

45 Control group Experimental group Mean Standard deviation 4 There are usually a large number of measurements. Group your data and list the frequency (and % frequency) of each. Group Frequency % frequency 5 Draw a histogram showing the distribution of your measurements. Label the axes. Give the graph a title. Use the graph paper on the next page. 6 Describe the shape of the graph. Does the plant characteristic you measured show a normal distribution? 7 How varied were the measurements? 8 What conclusion can you draw from this activity? Part 4: Grape improvement 45

46 Exercise 4.2: Improving on nature Currently in Australia research programs are producing new and improved agricultural plants using traditional breeding programs and biotechnology. 1 Lawson is a high yielding wheat variety bred for high rainfall areas. This self pollinating plant was produced by a traditional breeding program. Outline the steps you think the CSIRO followed to breed this plant. _ 46 Grape production