Fungal and bacterial heart rots

The Vegetation Heart Causes

Fungal heart rots 'top rot' in Australia , as well as root rot of pineapple, are diseases associated with wet environmental conditions. P. cinnamomi Rands requires cool conditions and heavy, wet, high-pH soils. Heart-rot mortality can range from 0 to 100 , depending on the soil type, pH and rainfall. The economic impact of heart rot results from a reduction in plant densities due to plant mortality. However, adjacent plant mortality is partially compensated for by increased exposure of the...

Inflorescence and fruit

Inflorescence Pineapple Fruit

The peduncle and inflorescence develop from the apical meristem, the diameter of which is suddenly increased until the initiation of the peduncle Kerns et al., 1936 . The stage of inflorescence emergence is called 'red heart' because of the five to seven reddish peduncle bracts at its base. These bracts Fig. 2.3. 1. Diagram of a transverse section of a 'Smooth Cayenne' leaf showing a.c., aerating canal f.s., fibre strand e, epidermis v.b., vascular bundle m, mesophyll ws.t., water-storage...

Chemically induced flowering

In the early 1700s, fumes from fires used to heat pineapple houses were observed to force the induction of flowering and this finding led to the commercial use of smoke for this purpose. The active ingredient in smoke was shown to be ethylene Rodriquez, 1932 and later work Kerns, 1936 showed that acetylene also forced flower induction. This finding prompted the use of carbide as a source of acetylene, a method still widely used on small farms. A pea-sized amount of calcium carbide is dropped...

Plant Nutritional Status

Nutrient Deficiency Pineapple

The nutritional status of the pineapple plant has a large influence on plant growth and, consequently, on yield and fruit quality. For pineapple, plant indicators that reflect plant nutritional status have been identified and, in conjunction with soil analysis, can be used to manage fertilization of the pineapple crop. The alternative to the use of plant indicators and soil analysis is the use of calibrated fertilizer trials in each area where the crop is grown. This practice is more common...

World Production and Trade

Pineapple Fruit Longitudinal Section

Pineapple is now the third most important tropical fruit in world production after banana and citrus. The processing of pineapple has made the fruit well known throughout the temperate developed world. Major pineapple products of international trade are canned slices, chunks, crush (solid pack) and juice and fresh fruit (Fig. 1.2). International trade is dominated by a few multinational companies that have developed the infrastructure to process and market pineapple. Thailand and Indonesia are,...

Plant indices of major mineral deficiencies

Nitrogen is required by pineapple in greater amounts than any other nutrient except potassium. Providing adequate supplies of N to rapidly growing plants is essential to maintain high rates of growth and produce good yields. Both leaf size and number may decrease when nitrogen is deficient and fruit and crown mass are consequently reduced. Slips may be absent on plants that normally produce them. Plant indices for nitrogen include leaf colour and nitrate-nitrogen in leaf basal white tissue,...

Assessment of nutritional requirements

Pineapple responses to nutrient management are dramatically affected by the condition of the soil and the health of the developing root system. Pathogens, nematodes, waterlogging and impermeable soil easily inhibit the crop from assimilating nutrients and responding to fertilizers. Indeed, several symptoms due to stress in pineapple are easily misinterpreted as nutritional deficiencies. When optimum growing conditions prevail, particularly for the roots, significant economical responses can be...

Determination of water requirements and plant moisture status

While the pineapple plant is a xerophyte and is capable of good crop production under relatively low water regimes, the plant responds well to as much as 5 cm (2 in.) of water per month from rain or irrigation (Fig. 6.16). Maintaining readily available soil moisture in the immediate root zone requires less water for pineapple than for other crops that have much higher transpiration rates. The entire pineapple plant adapts to drought and thereby maintains a productive potential in dry soil....

Soil amendments and fertilizers

Soil amendments, such as lime and organic matter, influence plant growth indirectly by improving the physical or chemical condition of the soil, though amendments gener ally also provide plant nutrients. Composted animal manures provide organic matter and improve soil structure, while supplying plant nutrients. Lime adjusts soil pH, as well as supplying calcium, and, if from dolomite, it also supplies magnesium. Pineapple root development can vary dramatically among locations, so a...

Nutrient absorption and growth

Pineapple plant nitrogen and potassium requirements are low until about 4 months after planting (Lacoeuilhe, 1978 Ingamells, 1981), after which requirements increase with growth until flower induction. In an experiment where 8 g of N and 20 g of K2O were provided for each plant prior to forcing, at the time of forcing at 10 months after planting plants of 375 g dry mass contained 5 g N and 11 g K (Lacoeuilhe, 1978). Plant nitrogen content remained constant during the period from forcing until...

Postplant sidedressings and foliar fertilizers

Side-dressings or foliar fertilizers are used where nutrients in the soil are not sufficient to meet the plant's nutrient requirements. Fertilizer may be applied as a dry side-dressing to the soil, often close to the base of the plant or, in some cases, in the lower leaf axils of mature plants. Care must always be taken to avoid plant damage due to exposure to high osmotic concentrations from dissolving nutrients. The basal white tissue of young and expanding leaves is particularly sensitive to...