CHAPTER 1 INTRODUCTION Traditionally flowers are grown for aesthetic, social functions, extraction of essential oils and manufacturing of perfumes (Byczynski, 1997). But now, floriculture has been identified as a potential business due to divergence of farmers towards high value floral crops and utilization of flowers in social and industrial level in Punjab, Pakistan. Hence commercial floriculture has emerged inside the country. The most important floricultural crops in the Pakistan cut flower trade are Roses, Tuberoses, Gladiolus, Iris, Carnation, Narcissus, Lilies, Freesia, Statice and Gerbera etc (Riaz et al., 2007). Pakistan falls in the arid to semi arid climatic region of the world. Potential evapotranspiration is considerably higher as compared to rainfall received. High temperature promotes capillary movement of salts upwards causing deposition of salts on the soil surface. The country has the largest contiguous irrigation system in the world, irrigating over about 17 million hectares, and accounting for 90 percent of the agricultural production in the country (GoP, 2002). Even then the existing canal supplies are insufficient to meet the crop water requirements. Increased pressure of population has catalyzed the need to bring more area under cultivation to fulfill the food and fiber demands. To bring more area under cultivation or increased in cropping intensity, some additional water is required, but under the existing situation one of the alternative is the exploitation of the groundwater reserves. (Chaudhry et al., 2000, 2001, 2002, Aslam et al., 1998; and Gupta et al., 1995). However, another option is efficient use of available water resources or to conserve soil moisture (Ahmad et al., 1993; Dixit et al., 1971; and Kaseem et al., 1977). Tuberose (Polianthus tuberosa L.) member of Amaryllidaceae family, native of Mexico, is widely grown in Asia. Tuberoses are among the most fragrant of all garden plants and are easily cultivated. It is usually cultivated in Morocco, France, Hawaii, South Africa, 1 India and China. The growers commonly use the two well-known tuberose varieties Single Mexican and The Double Pearl. The former is preferred for its enticing fragrance, while the Double Pearl is preferred in flower arrangements due to the density of the flowers on its spikes. The Pearl also exudes fragrance characteristics of the tuberose, but to a lesser extant than the Single Mexican variety. Single flowers have 6 petals while double have 12. Tuberose blooms in late summer/autumn. Clustered spikes of tuberose are star shaped and waxy loosely arranged on spikes that can reach 3 to 4 feet in height. It is mostly grown around living areas for cut flowers, perfumes, fragrant oil, or garden beds. For mass effect in the border space the corms are planted 4-6 inches apart and at a depth of 2 inches. Mid spring is the best time to set out new corms. It can be grown successfully in warm and humid areas with optimum temperature of 30°c. Loamy and sandy loam soils with pH 6.5-7.5 are the best for its growth. Normal watering is required during drying period. Well-rotted animal manure, blood and bone or a complete fertilizer should be added in the soil before planting for its better growth. They have been grown commercially for florists and bulb distributors. The blossoms are also popular in weddings. The flower is very popular for its long spike; strong fragrance and its essential oils are important components of high-grade perfumes in southern France. It is one of the world′ s most costly perfume ingredients worth more than its weight in gold. As tuberose is summer crop that produce flowers from April to September, due to its great demand it is possible to advance the off-season flowering conditions through tunnel technology techniques. Conditions of Faisalabad are suitable for the early crop production through tunnel technology that extends the growth period and flowering quality of the crops. The climate of Punjab is suitable for simple unheated poly/plastic tunnels for indoor vegetable production that is well suited for the over-bridging the gap in markets during the cool months or to extend the season to be earlier in the market than the produce of the open field. The plastic covering protects the crops from rainfall, by reducing the amount of foliar diseases common in field production tomatoes. 2 Enhanced early season production and improved quality are important factors for warm season crop growers. The intent is to grow crops where otherwise they could not survive by modifying the growing environment to prolong the harvest period, often with earlier maturity, greater yield and improved quality, making commodities available when there is no outdoor production (Wittwer and Castilla, 1999). Therefore growers who have the ability to modify their climate have a competitive advantage over growers in the same region that do not have the ability to manipulate their climate. Mulching is the common and cheapest method for the weed control. Weeds are major problem in agricultural production throughout the world. In order to maintain good yields of crops, weeds must be controlled. For these reasons mulching is more common in organic farming and its benefits include weed control, soil moisture conservation, and soil temperature moderation (Larsson et al., 1997). Plastic mulches affects plant microclimate by modifying the soil energy balance and restricting soil water evaporation, therefore affecting plant growth and its yield (Tarara, 2000). Black plastic mulch, the predominant color used in crop production, is an opaque black body absorber and radiator. The efficiency with which black mulch increases soil temperature can be improved by optimizing the transferring heat from the mulch to the soil (Lamont, 1999; Aniekwe et al., 2004). Some mulch materials such as the reflective mulches are efficient in repelling insects (AVRDC, 1990). Humic acid contributes about 60 % of soil organic matter (Varanini and Pinton, 2006). It is reported that humic acid shows best results relating to plant growth in soils, which have low organic matter. So it is essential that before the application of humic acid, the organic matter status of soil must be known (Lee and Bartlett, 1976). Application of humic acid in combination with synthetic fertilizers produce synergistic effects on plants by enhancing morphological, biochemical and production attributes (Babeanu et al., 2003). It is also reported that application of humic acid increases the leaf area, leaf nitrogen and chlorophyll content (Murillo et al., 2005). 3 Many researchers have reported that CaC2 is the potent source of plant hormone, ethylene (C2H4) which induces improvement in yield of wheat, cotton, rice and Maize crops inn response to the soil application of coated CaC2 (CCC). Calcium carbide, when applied to soil it reacts with water to release acetylene (C2H2), which is reduced to ethylene (C2H4) by soil microbes. Ethylene is a plant hormone and it significantly affects plant growth and development at extremely low concentration. On the other hand, acetylene is an effective inhibitor of nitrification and denitrification (Arshad and Frankenberger, 2002; and Aulakh et al., 2001) and one of the best tools to enhance nitrogen use efficiency (NUE). Recent studies highlight the importance of ethylene as plant growth hormone. However, limited use has been made of C2H4 for the improvement of agricultural productivity because of gaseous nature and the difficulty in its direct application to soil I the field. Because it is highly flammable and explosive, so exposure to gas cause dizziness and could cause suffocation from decreasing the amount of oxygen. The minimum explosive concentration (3.1%) exceeds the suggested ethylene concentrations for tomato ripening and citrus degreening respectively by 200 and 6200 times (Sharma and Yadav, 1996). One of the more commonly used forms is the ethylene-generating chemical (2chloroethyl) phosphonic acid, known as ethephon (liquid) was develop in 1960s, when releases C2H4 chemically when absorbed by the plant tissues. This is mostly used for pre harvest applications (Sharma and Yadav, 1996). Quality production needs various nutrients that are applied by organic and inorganic means. Chemical fertilizers have vital role in growth, quality of flowers, corm and cormel production for growing Tuberose. The growers do not have any recommended doses of chemical fertilizers especially micronutrients for quality spike, corm and cormel production. Resulting, they are deprived of getting optimum size of spike, corm and cormels for flower cultivation. Intensive cut flower production demands high level of fertilization. Improper fertilization in combination with excessive irrigation may contribute soil and environment pollution. 4 Flower crops are very much responsive to fertilizers. So, it requires higher amount of chemical fertilizers in balance proportion for ensuring maximum flower production. Major nutrients like nitrogen. Phosphorus, potassium along with micronutrients noticeably increases the number of flowers, florets/spike, the longest spike and flowering stem of gladiolus (Afify, 2005). It was also reported that hardiness of the stick, flower color and post-harvest life could be prolonged to some extant by applying micronutrients along with blanket dose of NPK and Mg. However, information regarding nutritional requirements and appropriate soil management practices are lacking foe gladiolus cultivation in Pakistan. Most of the soils of Pakistan have pH value (alkaline), which hinders the absorption of micronutrients. Foliar application is one of the methods to overcome this failure of plants to absorb certain micronutrients in plant structure and physiological processes they are treated as the limiting elements for good spike, corm and cormel production (Halder et al., 2007). Although plant disease resistance and tolerance are genetically controlled (Agrios, 2005) they are affected by the environment and especially by nutrient deficiencies and toxicities (Marschner, 1995). The physiological functions of plant nutrients are generally understood, but there are still unanswered questions regarding the dynamic interaction between nutrients and the plant pathogen system (Huber, 1996). The combination of organic matter and mineral fertilizers provides the ideal environmental conditions for plant growth (Abdel et al., 2007). Keeping in view the significance of early crop production in the world, a field experiment was executed to find out the effect of low tunnel, calcium carbide, humic acid and micronutrients on important flowering crop of tuberose (Pollianthus tuberosa L.). 5 CHAPTER 2 REVIEW OF LITERATURE The relevant literature in respect of present experiment available within and outside the country is reviewed as under: Compared to macronutrients, micronutrients are usually required in small amounts and can be applied through foliage as plant is normally completely left as wet. For the leaves to absorb them, the micronutrients must be applied as foliar spray. Foliar application provides: • • A rapid response and is recommended when fast correction is necessary. A homogeneous distribution of a small quantity of micronutrients on a relatively large surface. Micronutrients improve general condition of plants and are known to act as catalysts in promoting organic reactions taking place in plants (Patil et al., 2008). Being involved in physiology of plant micronutrients contribute to the growth and yield of the plants. It is realized that productivity of crops is being adversely affected in different areas due to deficiencies of micronutrients (Bose and Tripathi, 1996) which has been increased markedly due to intensive cropping, loss of top soil by erosion, loss of micronutrients by leaching, liming of soil and decreased availability and use of farm yard manure (Fageria et al., 2002). Adentunji, (1990) found that mulching reduced the daytime temperature and conserved soil moisture content. They revealed that growth and yield attributes of lettuce were significantly higher under groundnut shell and millet – Stover mulches than in sawdust mulch and control. Irrigating at 7 days interval is more economical, while soil temperature above 25 ºC is deleterious to the normal growth and yield of lettuce. They suggested that lettuce requires a soil moisture content corresponding to at least 60 % plant available water in the 12 cm of soil for optimum yield and this can be provided with about half of the amount of water with mulching than without mulching. 6 Dahnous et al. (1992) studied the effects of foliarly applied ethephon on field grown plants of wheat, barley and triticales and found that treatments reduced elongation on tall cereals and increased the harvestable yield by reducing lodging. Wiersma et al. (1996) studied the effect of plant growth regulator (PGR) ethephon (ethylene releasing liquid compound) on yield, lodging and plant height of wheat. The study showed that ethephon reduced lodging and plant height, and increased grain yield on an average b 6.4 %. According to Rao and Fritz (1997), foliar application of ethephon increased yield of rice by 10-45 %. When roots of intact seedlings are grown in well aerated conditions, small concentrations of ethylene provided by ethephon usually well below 1 uL have been found to promote root elongation in many species including broad ban (Vicia faba), rice, tomato (Lycopersicum esculentum), maize and peanut (Arachis hypogea). It can also increase seedling root length in watermelon (Citrulus Anatus). Downer and Faber, (1993) showed no deleterious effects when mulched with either composted or fresh Eucalyptus cladocalyn F. Muell. in different landscape plantings. They observed that mulched trees were less stressed (increased stomatal conductance), and should resistance in dormancy for longer period of time and had greater root lengths than unmulched trees. They also found that mulched soils held more available water than unmulched soils and produced 80 % fewer weeds. Where as composting had little effect on tree performance and was deemed unnecessary. Chen et al. (1994) in a field experiment with cotton measured effect of nitrapyrin, acetylene (provided by wax coated calcium carbide) and phenyl acetylene on N transformation and de nitrification following pre sowing application of urea. They found that losses of urea were reduced to 35-57 % in February (from 84 % of applied N) by the application of nitrapyrin and Phenyl acetylene and nitrapyrin reduced losses over 24 weeks of sowing 57, 52, and 48 % respectively. Bibik et al. (1995), after being inspired by muromtsev’s work, conducted two year trials with potato in order to evaluate effect of Retprol (calcium carbide based formulation)and CaC2 (in Liquid). They reported that the application of Retprol and CaC2 to soil resulted 7 in increased number of tubers and tuber yield. They further observed that the degree of response to both compounds was depended on the varietals features of the potatoes. The application of various amounts of the C2H4 generating products (Retprol and CaC2) increased the number of tubers by 25-80 % and tuber yield by 29-121 % for both varieties tested. They reported more effectiveness of patrol than CaC2. Chaiwanakupt et al. (1996) also explained that addition of wax coated calcium carbide effectively inhibited the process of nitrification and increases grain yield of rice up to 31 %. Vos et al. (1995) scrutinized the positive effects of mulch on health of hot pepper crop. Mulch materials consisted of rice straw and white or silvery plastic foils. Rice straw mulch had variable effects on crop health. White and silvery plastic mulch reduced thrips injury and delayed virus epidemics. The overall positive effects of plastic mulch on crop health contributed to improved crop production. Mulching is therefore recommended as a component within an integrated crop management (ICM) programmed for hot pepper. Pinamonti, (1998) tested two composts as mulching materials in a vineyard: one was sewage sludge and bark compost with low heavy metal content, the other was municipal solid waste compost with a higher concentration of metals. They reduced soil temperature fluctuations, reduced evaporation of soil water, and influenced the levels of some nutrients measured in leaf samples. The data obtained show that the nutrients uptake was more influenced by the physical conditions of the soil (temperature, moisture) than by the availability of nutrients in the soil. Both the compost mulch materials had considerable advantages for the soil management on the grapevine rows, by reducing chemical weed control and allowing for the substitution of chemical fertilizers with no loss in vigor, yield or quality of musts. Schonbeck and Evanylo, (1998) evaluated the effect of hay, compost, plastic and paper mulch on soil temperature, soil moisture and yield of tomato. They found that organic mulches reduce soil temperature and maintained higher soil moisture levels than other treatments. Increased in temperature by 1-2 °C and 4 °C respectively by black plastic mulch and oiled paper with slight decrease in soil moisture in lateral one. Differential 8 yield response was observed by influencing and modifying soil temperature regime and soil moisture level respectively with highest yield in black plastic mulch and lowest in organic mulches, with paper mulch intermediate. Olasantan, (1999) conducted an experiment to observe the influence of mulching on the hydrothermal regime and emergence, growth and tuber yield of white yam. Significant improvement in the soil moisture content of the 15 cm surface layer by 50 ± 120 g / kg was observed and decreased the maximum soil temperature by 2 ± 78C at 15 cm depth in the early growing season (March ± April). The emergence and development of yam seedlings were significantly lower in unmulched plots than in mulched treated plots. Mulching significantly increased tuber yield by about 10 ± 15 mg / ha / season. The number of leaves per plant, vine diameter and leaf index were also significantly greater in plots mulched in October ± December than plots mulched in January or February. Rodrigues et al. (1999) recorded the mulching effect on Rose plant cvs. Anna and Sari in closed soil less systems. There was a reduction in the water consumption of 35 or 16 % corresponding to cultivars Anna and Sari, respectively, when the plants were mulched. A lower electrical conductivity and higher water content of the mulched substrate were recorded both in fall and in spring/summer. The results showed significant differences in flower production and quality, using the mulched system. Higher water use efficiency was caused by lower evaporation and overall lower increase of the electrical conductivity of the substrate. Singh and Bhattacharjee, (1999) studied the concentrations of nutrients in tissue components of cut roses (Rosa hybrida L.) to assist in developing a fertilizer management system that sustains a high level of production but also is environment friendly. The flower represented 28.5 %, leaves 46.0 % and stem 25.5 % of the total weight of the stalk. However, actual rates of N and K, as well as other nutrients applied, should be adjusted based on soil and tissue analysis results. Removal of nutrients will be greater if stalks harvested are >45 cm in length, which may necessitate additional nutrient application, depending on soil conditions. 9 Haywood, (2000) checked the effect of different mulching and hexazinone herbicide. After three growing seasons, seedlings on the mulch and hexazinone treatments were taller than those on the check plots. About 59 % of the mulched and hexazinone treated seedlings had grown out of the grass stage (at least 12 cm tall) compared to 17 % of the check seedlings. After five growing seasons, the percentage of longleaf pine seedlings out of the grass stage was similar on all treatments and averaged 87 %. However, these better growing pines were taller on the mulch and hexazinone treatments (a 142-cm average) than on the checks (78 cm). Pine straw was ineffective mulch probably because the straw smothered the seedlings. The long life saplings were tallest when the perforated polyethylene mat was used. Mukesh et al. (2001) investigated the effect of foliar application of zinc, copper and iron @ 0, 250, 500 and 1000 ppm on the yield and quality of Gladiolus grandiflorus cv. Mirela. Plants treated with micronutrients exhibited better results with respect to growth, flowering and yield compared to the control. Foliar application of Fe, Cu and Zn @ 1000 ppm showed better results with respect to growth, flowering and other yield parameters. In general, the effective treatment for increasing the yield attributes and quality parameters of Gladiolus grandiflorus was foliar application of Zn @ 1000 ppm. Randall et al. (2001) studied the effect of acetylene generated from calcium carbide on nitrification in soil and yield of irrigated maize seedling and describe novel matrix consisting of calcium carbide and polyethylene that delivers acetylene in soil over extended period resulted in delayed nitrification. They found in irrigated maize (Zea mays L.) that the matrix delayed the disappearance of ammonium derived from urea but gave on benefit for crop yield in a soil that was highly responsive to N, where N losses (leaching and denitrification) were not significant. Shigfeumi, (2001) investigated the effect of nonwoven fabric mulching on yield and quality of cut flower in spray conditions. Under nonwoven fabric mulching, the yield in 4-row planting density with training was higher compared with that in conventional (6- 10 row planting density with training, but without mulching). Moreover, after pinching, but without training, the yield of mid and late season varieties under 4-row planting density and nonwoven fabric mulching, increased by 30 % (Light Pink Barbara) and 19 % (Scarlet Queen) compared with conventional cultivation. Under nonwoven fabric mulching and 4-row planting density, the quality of the second havest improved compared with that of under nonwoven fabric mulching and 6-row planting density. Kang and Iersel, (2002) studied the effect of nutrient solution concentration on growth of alyssum (Lobularia maritima), celosia (Celosia argentia), dianthus (Dianthus chinensis), gomphrena (Gomphrena globosa), stock (Matthiola incana) and Zinnia (Zinnia elegans). Plants were grown with five different concentration of Hoagland nutrient solution. The concentration of N, P, K, S, Ca, Mg, B and Fe in the shoots of dianthus increased while the concentrations of Mo and Zn decreased with increasing fertilizer concentration. Gomphrena and stock can tolerate relatively high levels of root zone salinity. Flower diameter of zinnia decreased with increasing nutrient concentrations. In general, the growing medium pH was similar with low concentrations (0.125, 0.25 and 0.5) but decreased with a further increase in fertilizer concentration. Mahmood et al. (2002) in a pot experiment studied the effect of time of application of encapsulated calcium carbide with and without NPK fertilizers on growth and yield of wheat. The study showed that plants responded positively to CaC2 application (60 kg ha1 ). CaC2 treatment after one week, of germination was most effective in increasing number of tillers, length of spikes, number of spikelets, total biological yield, straw and grain yield of wheat, while plant height did not increase significantly with the application of CaC2. Chemical analysis of plants revealed that K and P contents in grains and straw increased when CaC2 was applied with 120-90-60 kg ha-1 (N-P2O5-K2O) compare to fertilizer alone. Prabhat et al. (2002) stated that foliar application of 0.2 % FeSO4 singly or in various combinations at three leaf or six leaf stages of gladiolus induced flowering earlier than the other treatments such as ZnSO4 or MnSO4. It also increased plant height and number 11 of leaves. Spike length, number of florets, weight of spike and size of florets were significantly increased with 0.2 % FeSO4+ 0.2 % ZnSO4 application. Flowering duration was longest with o.4% FeSO4 + 0.2% ZnSO4 where as corm production plant–1 was highest with 0.4% FeSO4 + 0.4% MnSO4 + ZnSO4. Saleem et al. (2002) conducted a field experiment to evaluate influence of encapsulated calcium carbide on growth, yield and chemical composition of okra. They found that CaC2 application @ 90 kg –1 was most effective in increasing horizontal expansion of plant, yield of green pods, number of green pods per plant, fresh and dry weights of shoot and root and internodes length, while plant height decreased with increase in CaC2 application rate. The chemical analysis of plant material revealed that P and K in green pods and roots were increased with increase in CaC2 application rate. P contents in shoots were decreased while that of K increased with increase in CaC2 application from 0-90 kg ha-1. Salma et al. (2002) studied the effects of 50 mg L-1 levels of micronutrients (Zn and Mn), as single and combined treatments on the growth, oil yield and oil constituents of cumin plants. Application of micronutrients had significant positive effects, in most cases, on growth measurements and chemical composition of cumin plants. A combined treatment of the micronutrients gave the highest values in this respect. In the herb and seed oils, 21 constituents were identified, representing 90.2 and 95.6 % of the total amounts, respectively. Eleven components were similar in both herb and seed oils. Cumin aldehyde was found as the main component at concentrations of 53.6 % for seed oil and 40.5 % for herb oil. Among the new identified components in the seed oil were perilla aldehyde, acoradiene and benzoic acid 4-(1-methylethyl). These components were found in the herb oil, as well. The oils of herb and seeds of cumin contained considerable amounts of oxygenated monoterpenes. Both oils were characterized by small amounts of monoterpenoid and sesquiterpene hydrocarbons. Pervea et al. (2003) investigated that boron sprays in apple (Malus domestica) tree consistently increased fruit yield. Applying boron spray at the pink flowering stage 12 increased flower cluster and early season leaf boron concentrations. In the second study, one quarter of the annual boron fertilizer requirement was tank mixed with CaCl 2 sprays applied starting in the early June for bitter pit control. This treatment consistently increased “Scarlet Gala” fruit Boron concentration. The results of these experiment indicated that applying boron sprays at the pink flowering stage timing and mixing boron with CaCl2 sprays applied for bitter pit control are useful practices to enhance boron spray efficacy and convenience of application. Velinden, (2003) observed changes in the nutritional status of corollas during development and senescence. Petunia hybrida cv. Mitchell, s corollas were analyzed for macronutrients (N, P, K) and micronutrients (B, Fe, Cu, Mn, Zn, Mo) content, dry weight, fresh weight and ethylene production. Carbon content decreased at slightly lower rates than dry weight during corolla development between anthesis and senescence, while fresh weight and ethylene production followed pattern expected of climacteric flowers. Nitrogen, phosphorus and potassium content decline during development. Both phosphorus and potassium content gradually declined throughout development with overall losses of about 75% and 40% respectively. Nitrogen content declined 50% during development but losses occurred only during the final stages of senescence. No significant changes were observed in sulphur, calcium, magnesium and micronutrient content of the corollas during development. Wilson et al. (2003) checked the effect of compost media on wine sage (Salvia Spp. Sell X roenen Schultes Van Houttei), blue anise sage (Salvia gauranitica St. Hil. Ex Benth. Black and Blue), and indigo spires salvia (S. longispicata Martius Galeotti x S. farincea Benth. Indigo Spires). Initial physical, chemical and elemental analyses of the media indicated that compost alone had higher pH, electrical conductivity (EC), total porosity (TP), bulk density (BD), particle density (PD), N, C, P, Ca, Cu, Fe, and B. Heavy metal (Cd and Pb) contents of compost did not exceed EPA 503 Rule limits for biosolid usage. After 6 weeks, plants were measured for leaf nutrient content, growth (leaf and stem dry weights, stem lengths), and quality (number of flowers, leaf greenness, and subjective quality ratings). Plants grown in compost had leaf SPAD readings (leaf greenness), 13 number of flowers, and visual quality ratings that were generally similar (Indigo Spires) or slightly reduced (Van Houttei) than plants grown in peat-based media. However, for each species (except for Van Houttei grown in 505 compost using drip irrigation), plants were of marketable quality, regardless of irrigation system or medium. Chaudhry et al. (2004) evaluated the efficiency of different mulching materials on moisture conservation, soil properties and plant growth. The infiltration rate of the soil increased by 30 % at the end of the study. Maximum saving of 45 % irrigation water was recorded under polythene sheet followed by 30 % under rice straw and 15 % in mechanical loosing of soil. Maximum plant height was observed under mulching through mechanical loosing of indicating that mechanical loosing of soil had some positive impact on plant height where as non-application of mulching material had the minimum plant height. Gulshan et al. (2004) studied the effect of plastic mulching in bed planting method and concluded from the study that higher yield of baby corn can be obtained in bed planting method and further plastic mulching in bed planting method boosted the baby corn yield over unmulched soil condition. Plastic mulch increases minimum temperature of soil, accelerated early growth and plant height, fruiting of plants and gave satisfactory weed control without any application of herbicide. 14 Smit and Combrink (2004) evaluated the effect of nutrient solution on tomatoes in greenhouse. Four nutrient solutions with born at different levels (0.02, 0.16, 0.32, and 0.64 mg L-1) were used. Leaf analysis indicated that the uptake of Ca, Mg, Na, Zn and B increased with higher boron levels. At the low boron level, leaves were brittle and appeared pale green and very high flower abscission percentage was noticed. Fruit lacked firmness at the low boron level and this problem worsened during storage. At the 0.16 mg Kg-1 boron level fruit set, fruit development, color, total soluble solids, firmness and shelf life seemed to be close to optimum. The highest boron level had no determinant effect on any of the yield and quality related parameters. However, using “Soluber” as a source of boron, higher levels decreased soluble Mn concentration in nutrient solutions, probably owing to the precipitation of insoluble MnO2. This was reflected in reduced leaf-Mn concentration. Yaseen et al. (2004) conducted field experiment and pot trials to investigate the effect of calcium carbide on growth and yield of rice, wheat and cotton crops. The results showed that encapsulated calcium carbide released large amount of C2H2, which is slowly reduced to C2H4 by the soil microorganisms. It was observed that CaC2 slow down the release of NO3- from applied urea that might help in improving NUE. In another field experiment, Yaseen et al. (2005) evaluated the effect of encapsulated CaC2 on growth and chemical composition of rice (Oryza sativa L.). The results revealed that encapsulated CaC2 applied alone or along with chemical fertilizer significantly increased early emergence of panicle, number of tillers and paddy yield. Soil amended with encapsulated CaC2 resulted in 20 % increased in paddy yield over NPK fertilizer alone. Plant analysis also indicates that encapsulated CaC2 promoted N concentration and uptake by plant, which is supported by the reduced oxidation of applied fertilizer NH4+ to NH3- in the presence of encapsulated CaC2. Zheng et al. (2004) studied the effect of nutrient solution on potted gerbera (Gerbera Jamesinii “Shogun”) under recirculating sub irrigation conditions. Plants were grown under one of four nutrient levels. Leaves from plants that received 10 % and 25 % strength solution showed significantly less greenness than that of the plants that receive 15 50 % and 100 % strength nutrient solutions. There were intervienal chlorosis symptoms on the younger leaves of some plants in the 10 % and 25 % strength nutrient treatments. It is suspected that this intervienal chlorosis was due to iron (Fe) deficiency caused by the increased substrate pH. Nutrient salts accumulated in the top section of the grown substrate under all treatments levels; however, no phytotoxic effects were observed. No differences in water use (141 ml plant-1 day-1) were observed among the various nutrient levels. Fertilizer inputs were reduced in the 50 %, 25 % and 10% treatments by 54 %, 75 % and 90 % respectively, relative to the 100 % treatment. After 4 weeks under recirculating conditions, the qualities of the nutrient solutions were still within acceptable limits. Ehret et al. (2005) studied the effect of non-recirculating (open) and nutrient system, or a recirculating (closed) nutrient system with or without one of five amendments on greenhouse roses. Recirculating had no effect on harvest parameters during the first 8 weeks of the harvest period, but had a negative impact on stem length during the second 8 weeks, and on stem number and length when averaged over the entire harvest duration. Differences were not likely caused by changes in electrical conductivity or macro nutrient concentrations of the nutrient solutions. Amendments to the recirculating solutions consisted of increased concentrations of Ca, B or Si, reduced pH, or use of an adsorbent resin to remove specific organic molecules. All amendments mitigated the negative effects of recirculation on at least two harvest parameters, but only during the second half of the harvest period. With the exception of the intentional changes, mineral status of the nutrient solutions was similar in all recirculating treatments. It is likely that the reduction in rose quality and quantity in recirculation is caused by a combination of factors, some of which were ameliorated through the addition of specific amendments to the solution. De et al, (2005) conducted an experiment to study the efficacy of some mulching materials for soil moisture conservation and yield of groundnut (Arachis hypogaea) in summer under rain fed conditions. The mulches used were water hyacinth (WH), rice straw (RS), banana leaves covered with grass (BL), jute stick (JS) and white polythene sheet (PS). The WH mulch conserved more soil moisture than the other mulches. The soil 16 temperature at the root zone depth was also reduced with the use of WH mulch. The mulches WH and RS manifested higher kernel yields of 0.67 and 0.61 t ha-1 respectively. The soil moisture content with ridge planting method was 8.4 %, significant higher than the planting method (7.3 %). Soil temperature with flat (33.7 °C) and ridge (33.2 °C) planting method were statistically similar. Henschke and Jerzy, (2006) conducted an experiment on height of shrubs, length of developed shoots, number of flowers and flower diameter shrubs of five rose cultivars from the ground cover group: Nozami, Alba Meidiland, The Fairy, Rote Max, Graf, and Sommerabend. Mulching with pine bark layer of 5 or 10 cm thickness was achieved on soil after planting of shrubs. The abundance of flowering in mulched shrubs increased seven and sixteen times. They concluded that mulched shrubs were higher and produced more shoot. Along with an increase in bark layer thickness, the height of plants also increased. Ramakrishna et al. (2006) studied the impact of mulching materials (polythene, rice straw and chemical) on weed infestation, soil temperature, and soil moisture on groundnut production. They recorded that polythene and straw mulch were effective in suppressing the weed infestation. Polythene mulch increased the soil temperature in winter by about 6-8 °C at 5 cm depth and by 4-8 °C at 10 cm depth. Mulches prevent soil water evaporation retaining soil moisture. Groundnut plants in polythene and straw mulched plots were generally tall, vigorous and reached early flowering. Szewezuk and Gudarowska, (2006) conducted an experiment to check the influence of herbicide fallow; mulching with pine bark; and mulching with Black polypropylene fabric in nectarine “Redgold” on seedling Prunus mandshurica. Using of plastic mulch improved the cropping of the trees in the first two years of yielding. The total yield for 8 years was higher in the case of the trees mulched with polypropylene fabric, but no significant differences were noted. Mulching with pine bark did not have the influence on the cropping of nectarine trees during the 8 years of yielding. The tree vigor, expressed by trunk cross- sectional area, was more intensive in the case of the trees mulched with 17 pine bark. Mulching with polypropylene fabric is the most advisable to control weeds in a nectarine orchard because of the lowest application of active substances ha -1. Wu et al. (2006) evaluated the effect of moss, sawdust or bark mulch and an un-mulched control on three years old highbush blueberry plants. Results showed that the growth under mulching treatment of “Bluecrop” were better than that under the control treatment. In “ Bluecrop”, plant height and width, shoot length, dry weight of 100 leaves and dry weight of roots were in the order of moss > bark > sawdust > control. The photosynthetic rate and respiration increased in mulched plants compared to the control and was in the order of moss > bark > sawdust. Mulching is an important method for blueberry cultivation and moss mulching was found to be the best. Amjad et al. (2007) studied the effect of plastic mulches in poly/plastic tunnel and concluded that vegetative and reproductive traits of hot pepper hybrids significantly improved by the application of plastic mulches in poly/plastic tunnels. Complete inhibition of weed growth was also observed under black plastic mulch that could be helpful to boost hot pepper production in poly/plastic tunnel. Kar and Kumar, (2007) observed higher yield and better crop growth in the mulched plots, which might be due to conservation of soil moisture and reduction of soil temperature by 4-8 °C. Straw mulch at a rate of 6 t ha-1 was applied during the first earthing up in half of the plots to observe the variation of plant growth, water use efficiency and tuber production between mulched and non-mulched plots. Two years of pooled data with four irrigations resulted in air-dry tuber yields of 14.9 and 11.2 t ha -1 for the mulched and non-mulched plots, respectively. Significantly (p