Why do pineapples represent weed

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What about the Pineapple? Published: February 16, Share This:. Thank you! Your message has been received. We will get back to you shortly. Thank you for registering. Boletim de Pesquisa, 1. Therefore their initial development after planting in the fields is slower and its overall performance is closer to that of small crowns. Aspects of plantlets production by plant sectioning -There are several ways for this process to be carried out, depending on factors such as the source of raw material, the size and the infrastructure of the nursery, the cultivar used, the local environmental conditions and even the time period available until reaching the season favorable for planting the plantlets in the field.

According to these authors the steps until the conclusion of planting of the stem sections in nursery beds include: Selection of plants supplying stems, harvest and preparation of the stems, sectioning, sanitary treatment of the sections, preparation of the nursery beds and planting of the stem sections.

Thereafter the cultural practices needed for bud emergence and plantlet development include: Watering, fertilization, weed and pest control, plantlets harvest and grading for field planting. If selection is done before fruit harvest, fruit size and shape may be used as additional criteria for selection. Plants selected have to be marked in some way in preparation of their harvest. This harvest should be done as soon as possible after fruit removal, as plant vigor tends to decline over time as stem reserves are consumed during the growth of suckers and ratoon crop development.

Selected plants are removed from the soil and their stems are cleaned by cutting off the entire length of leaves except for the basal sheath portion, peduncle and roots. The basal leaf sheaths help to protect the underlying buds from direct sun radiation and lesioning by sun burning.

After their transport to the nursery location, the stems are cut into pieces. The size of the pieces may be variable; however, pieces containing visible buds and associated with larger storage reserves will develop faster in the nursery than smaller pieces with no visible buds. As an alternative they suggested cutting the stems into transverse discs slices 2 to 3 cm thick. The leaf sheath remnant attached to each piece will protect the buds in the event that the nursery beds are not protected against direct sun radiation.

During sectioning any pieces with rot or other symptoms of fungal attack are discarded. Sections should be dipped into a fungicide-insecticide suspension for at least three minutes to control fungi, mealybugs and mites, pests that are largely present in lower leaf sheaths of pineapple plants.

A few hours after this treatment or at the most next morning, the treated stem sections should be planted in the nursery. Disc-form pieces must always be planted horizontally and slightly covered with soil while sections obtained from stems cut lengthwise may be planted vertically, the most common practice, or horizontally , in either case the buds are oriented upwards..

Nursery beds may be of variable dimensions, but their length and especially their width must be convenient for carrying out post-planting practices, usually not larger than 1. The bed should be raised by at least 10 cm and the soil must drain easily, be well aired and fertile, and these goals may be reached by the application and incorporation of organic and mineral fertilizers some time before planting.

And weeds must be controlled, manually, mechanically or even chemically. The application of a pre-emergent herbicide, such as diuron, registered for pineapple crops, over the prepared and humid seedbeds a week before planting the sections, may control most weeds for months and thus reduce the costs and laborforce needs. After planting the nursery beds must be kept under humid conditions.

In most situations regular irrigation must be supplied, at least once a day. A soil cover with dry biomass or even with a plastic film may reduce irrigation frequency and help to control weeds. It takes about one to two months until the buds sprout and their leaf growth is clearly visible, a period variable with environmental conditions, cultivar, section size and even mother plant age and vigor.

This initial growth is mostly sustained by the storage reserves of the section, but from about six weeks after planting nutrients should be supplied by foliar feeding with a dilute nutrient solution containing NPK and micronutrients with an initial concentration of about 0. Applications of fungicide and insecticide to keep fungi like Chalara paradoxa, mealybugs Dysmicoccus brevipes and mites Dolichotetranicus floridanus under control may be necessary depending on environmental conditions.

Any plantlet with rot or wilting symptoms must be discarded. After reaching a minimum size of 30 cm, considered an adequate length for planting in the field, the plantlets are pulled from the soil and separated from the remnant stem section. Usually a significant part of the roots is attached to the section and hence eliminated together with the section. This looks like a negative aspect, as plantlets may develop more rapidly in the field if they have a well-developed root system at the time of planting, an observation made by authors like Hepton HEPTON, A.

Before taking the plantlets to the field, a last visual selection should be done and any unhealthy looking material eliminated. If grown in nurseries under shade or greenhouse conditions all material should be hardened by gradually increasing the sun exposure before planting.

All the steps described above for stem sections also apply to sections obtained from suckers, slips or crowns, but their apical meristem must be eliminated. These materials usually give smaller pieces than those obtained from plant stems and hence present higher environmental and management requirements for sprouting and development.

When rather small sections are produced, they are best planted in sterile media and grown in the greenhouse. Small crown sections should be started in a well-drained medium, such as coarse sand, and must be kept moist. There are several plantlet production systems that can be used by growers and planting material producers, as each one has to be adapted to the availability of infrastructure conditions and other needs which influence costs and yield of material ready for planting.

This same system, using as source pineapple plant stems available after fruit harvest, was improved by Matos et al. After quick drying these pieces were planted with their buds directed upwards in a seedbed of washed coarse sand or saw dust within trays distributed inside a screenhouse.

Adequate humidity of the environment and the planting medium was maintained using a microsprinkler irrigation system. Within about eight days sprouting of the buds initiated and after 30 to 45 days plantlets reached sizes of at least 2 cm and were then detached from their stem sections and transplanted to ml tubetes containing organic compost and kept in the same screenhouse conditions.

As the plantlets grow they are fed with foliar fertilizers, mostly supplying nitrogen and potash, and are inspected for their vigor and sanitary quality. If needed, pesticides are sprayed. Matos et al. Another way to remove the growing point is by inducing plants to flower and later on breaking off the developing inflorescence PY et al.

These buds form shoots, which, when large enough, are harvested and planted in a nursery or field. In the field, plants should be larger at least 0. The gouge should be shallow, preferably not more than about 1. Treatment of the gouged plants with fungicide is recommended to avoid rot. Shoots produced after gouging are allowed to grow to the desired size and their mass at the time of removal depends on the conditions under which they are to be planted.

Very small plants, less than 50 g or so, would normally be planted in a greenhouse under shade. Plants weighing between 50 and g could be planted in a propagation bed in the field, while plants weighing g or more are suitable for use in establishing commercial plantings.

A well-maintained mother-plant nursery can be productive for 8—12 months, after which it can either be rejuvenated by allowing at least one low-attached shoot to grow until it is of gouging height or the nursery plants can be diced or removed and the nursery area replanted HEPTON, HEPTON, A. The number of plantlets obtained with this technique depends on many factors, among those plant vigor, cultivar, environmental conditions and cultural practices, but plantlet size, height or weight, is the most important one.

Pinon, cited by Py et al. Smooth Cayenne. Flowering of the suckers was forced 2. The same author observed that after gouging the production of suckers per plant of cv.

Kew did not decrease with increasing planting density up to Acta Horticulturae The Hague, v. In Mexico, Rebolledo-Martinez et al. Suckers production of MD-2 hybrid pineapple by three methods: Gouging, leaf pruning and a growth Regulator. By chlorflurenol treatment -Another way to produce pineapple plantlets is by chemical stimulation of the plant during the initial phase of its reproductive differentiation. Plants are submitted to flower induction treatment following normal farm practice and a week or more later sprayed with a solution of up to ppm of chlorflurenol, a plant growth regulator belonging to the morphactin group, diluted in l per ha PY et al.

This treatment stimulates the development of propagules in place of flowers and fruitlets. The number of propagules and their position on the inflorescence depends mostly on the timing and concentration of chlorflurenol. Chlorflurenol on smooth cayenne pineapples. Information bulletin observed that spraying chlorflurenol solution at one, three, six and nine weeks after the flower forcing treatment resulted in the formation of propagules over the entire inflorescence, over half, a third or none of it, respectively.

At nine weeks the effect was mostly a reduction of crown size. The size and number of propagules is rather variable, but they are usually small and formed in large number, that is, up to thirty per plant with an average weight of 60 g per plantlet PY et al. Pineapple slip production using the morphactin multiprop applied after flower induction with different chemicals. In a test carried out at Embrapa, 6.

Propagules should be carefully graded by size before planting. The small ones have to be grown to larger sizes in a nursery before planting in the field. These propagules may represent an important type of planting material in fresh-fruit operations where crowns are sold with the fruit and the availability of slips or suckers is too low to meet planting-material demands HEPTON, HEPTON, A. However, their production is rather expensive, as plants must be grown to a minimum size for flowering forcing and no fruits are harvested, differing from plantlets obtained by plant stem sectioning after fruit harvest.

In subtropical Hawaii where suckers develop along with the fruits, the costs of propagule production with chlorflurenol were kept low by forcing flowering of shoots that would normally produce a ratoon crop, A few days after forcing the shoots were sprayed with a chlorflurenol solution to initiate propagule production D. Bartholomew , personal observation. While the ratoon crop was lost, there was no cost of land preparation or planting and little cost except for an occasional nutrient spray to support growth of the suckers and the developing propagules.

By micropropagation -Micropropagation techniques for obtaining plantlets on a commercial scale have been one of the biotechnological advances with significant impact on agriculture in the last 30 years. Micropropagation has made great contributions to the vegetative reproduction of several crop species, accelerating propagation of new important genotypes and producing a large number of plantlets in a rather short time and often of better quality than that of conventional planting material.

The successful application of this technique depends, however, on a number of factors that need to be controlled, such as the genotype, the origin, type and physiological age of the explant, and the culture medium, among others. Potential low cost micro-propagation of pineapple Ananas comosus. South African Journal of Botany, Amsterdam, n. Cultivo inicial in vitro de gemas axilares de Ananas comosus L. Effects of benzylaminopurine and naphthalene acetic acid on proliferation and shoot growth of pineapple Ananas comosus L.

African Journal of Biotechnology, Nairobi, v. A novel approach for rapid micropropagation of maspine pineapple Ananas comosus L. Nodule cluster cultures and temporary immersion bioreactors as a high performance micropropagation strategy in pineapple Ananas comosus var.

Development of an efficient protocol for micropropagation of pineapple Ananas comosus L. African Journal of Agricultural Research, Nairobi, v. Micropropagation and growth of in vitro pineapple Ananas comosus Merr in Iran. Plant Archives, Muzaffarnagar, v. In vitro growth and multiplication of pineapple under different duration of sterilization and different concentrations of benzylaminopurine and sucrose.

Effects of immersion system and gibberellic acid on the growth and acclimatization of micropropagated pineapple. Global DNA methylation levels during the developmentof nodule cluster cultures and assessment of genetic fidelityof in vitro-regenerated pineapple plants Ananas comosus var.

Journal of Plant Growth Regulator, Dordrecht, v. Plant Cell Culture e Micropropagation, Lavras, v. Viability and genetic stability of pineapple germplasm after 10 years of in vitro conservation.

The growth and nutrition of pineapple Ananas comosus L. Currently, conventional techniques of micropropagation have been routinely used in the process of multiplication of new hybrids by research institutions, even though the protocols must be adjusted for each new variety. This process is influenced by many factors, but the most important ones are the genotype, the parent plant, the explant type part of the plant to start the process and the culture medium, which will be addressed in the following paragraphs.

The influence of the genotype on the in vitro morphogenetic behavior has been recorded for several species, revealing in most cases responses that define the need for specific protocols TORRES et al. In micropropagation of pineapple, the genotype has a strong influence. Silva et al. After four subcultures, differences were observed, not only among botanical varieties, but among genotypes of the same botanical variety, confirming this genotype effect on the in vitro multiplication of pineapple.

The parent plant serves as donor of the explant, which is a segment of plant tissue or organ removed from its natural site and used to initiate an in vitro culture. The phytosanitary condition of this material is of crucial importance for the success of the cloning process.

Multiplication of infected material as well as the physiological conditions and the sterility of the starting material strongly influence the in vitro morphogenetic potential of the buds. To assure that micropropagated plants are disease free, it is recommended that parent plants be indexed for viruses, especially for the wilt virus transmitted by mealybugs known as PMWaV Pineapple Mealybug Wilt Associated Virus. The explants most used for the establishment of in vitro pineapple are axillary buds coming from pineapple slips or hapas, but it is also possible to use buds obtained from suckers.

The planting material used may be 15 to 50 cm long and present 10 to 20 buds, depending on the variety. Pineapple crown buds are another alternative, but they are less available as the crowns are usually sold together with the fruit on fresh fruit markets.

The culture medium basically consists of a mixture of mineral salts, a sugar usually sucrose as a source of carbon and energy, growth regulators, amino acids and vitamins, among other components.

A revised medium for rapid growth and bioassays with tabacoo tissue culture. Physiologia Plantarum, Lund, v. Usually no growth regulator is added during the first 45 days of cultivation.

For pineapple, the concentration of BAP has varied from 0. Main stages of the micropropagation process Once buds have been removed from the parent plant, the first step is disinfestation to eliminate microorganisms present and thereby minimize the chance of fungal and bacterial contaminations.

Under fully aseptic conditions in a laminar flow chamber, these buds should be further reduced removing excess tissue prior to their introduction into the culture medium Fig. The swelling process of pineapple buds Fig. At 45 days after placing the buds into the culture medium, it is time to add growth regulators.

The presence of a cytokinin is critical for initiation of the process of cell division and its balance with an auxin, usually at a ratio of about , favors the elongation and subsequent rooting of plantlets.

When the first shoots or aggregates of shoots appear Fig. The first shoots may appear after about 90 days of cultivation, when the multiplication cycles have to be started by inducing latent buds present at the base of the small shoots, and thus to generate new individuals. Many varieties elongate in this same medium, however, other varieties need to be transferred to specific medium in a larger container for shoot elongation. Rooting of in vitro pineapple plants Fig.

The last stage of production of plantlets by micropropagation is acclimatization Fig. This phase involves the transfer of the plantlets from the in vitro condition to a greenhouse. This passage is quite critical and, in some cases, represents the main limiting factor of the micropropagation process. The plantlets should be potential Sucker insertion sites carefully removed from the vials, their roots thoroughly washed in running water to remove any residue of the culture medium, and transferred to small Styrofoam trays or tubes SOUZA et al.

As for the substrates, preference should be given to those with low density, good moisture retention and good aeration, including mineral supplementation. The time period needed for acclimatization and development of the plantlets until reaching a minimum size for planting in the field is rather variable.

Depending on the variety, environmental and management conditions this period may last up to eight months, but on average takes about five months. Methods in search of cost reduction and efficiency -In spite of its high multiplication rates, pineapple plantlets produced by micropropagation are rather expensive and production cost reduction has been a major goal BE e DEBERGH, BE, L.

Some methods and management practices have been developed looking for lower cost per plantlet obtained, among which can be mentioned the following: the use of a double-phase system, the production of plantlets by means of bioreactors with temporary immersion, etiolation in vitro shoot elongation and production of multiple buds in nodal segments. In this system, instead of subculturing the shoots by their transfer to a fresh medium a certain amount of liquid medium is added to the initial half-solid medium in which the explants were inoculated.

The system of micropropagation in temporary immersion bioreactors was first adapted by Escalona et al. New system for in-vitro propagation of pineapple Ananas comosus L. It allows the use of large containers, increasing efficiency with cost reduction and excellent survival rates during acclimatization when compared to micropropagation in stationary culture.

The establishment of the buds occurs by the conventional micropropagation system, in small containers, and the initial bud aggregates are then transferred to the bioreactors to start the multiplication phase. This technique alternates temporary immersion of the buds in liquid medium with periods of absence of culture medium, at regular intervals. Each unit of the system consists of two bottles, one containing a large volume of medium depending on the size of the vials and the other with the explants for multiplication.

These bottles are interconnected by means of a hose through which the culture medium passes from one bottle to another due to the activation of an air compressor FEUSER et al. The interval between immersions of the explants is variable and has to be adapted to the conditions of each species or cultivar.

The automation of the system reduces labor force needed for explant transfers between culture media and increases multiplication rates, as it avoids losses of the material by hyperhidration and asphyxia, and hence leads to reductions of plantlets production cost TEIXEIRA et al.

Documentos, Imperial: conventional systems in solid medium and in liquid medium MS medium supplement with 1. The authors observed that the temporary immersion system was the most efficient method for commercial pineapple micropropagation, which produced more, longer and heavier shoots.

However, research efforts continue in search of further efficiency and lower costs per plantlet produced.