Abstract: Somatic hybridization of mango via protoplast fusion was attempted at cultivar level. Enzymatically isolated protoplasts from leaves of greenhouse-grown seedlings of cvs. 'Tommy Atkins', 'Keitt' and 'Haden' and from proembryonic masses (PEMs) of cv. 'Kensington Pride' were used. Protoplasts were fused by polyethylene glycol (PEG), embedded in Ca-alginate beads and cultured in shallow liquid culture on shaker (30 rpm). After 4 weeks, Ca-alginate beads were depolymerized and released microcolonies of PEMs were plated onto the solid culture media. After two consecutive subcultures, fast growing large clumps of PEMs were picked up and cultured as PEMs line for analyses. Flow cytometry analysis of 242 PEMs lines revealed 41 tetraploid lines. DNA fingerprinting of the regenerated embryos from the tetraploid lines showed that only four lines were somatic hybrids, all resulting from 'Haden' + 'Kensington Pride' protoplast fusions. By contrast, the tetraploid lines from 'Keitt' + 'Kensington Pride' and 'Tommy Atkins' + 'Kensington Pride' were autotetraploids. Root-tip chromosome counts on resulting germinated cotyledonary embryos confirmed that somatic hybrid embryo lines had a chromosome number of 2n=4x=80 compared to diploid parents (2n=2x=40). Of 50 deflasked somatic-hybrid, in vitro plantlets with true leaves only 3 plantlets formed the healthy apical bud (meristem) in the soil and grew normally.
Shailendra Rajan, Divya Tiwari, V.K. Singh, Pooja Saxena, Shilpi Singh, Y.T.N. Reddy,K.K. Upreti, M.M. Burondkar, A. Bhagwan and Richards Kennedy
Central Institute for Subtropical Horticulture, Rehmankhera, Lucknow. Indian Institute of Horticultural Research, Banga?lore.
Abstract: Phenological studies are important for understanding the influence of weather dynamics on vegetative growth, flowering and fruiting on mango. BBCH (Biologische Bundesantalt, Bundessortenamt and Chemische Industrie) scale was used for data recording and to assess utility of the scale in mango phenological studies. Phenological stages of the mango were recorded at weekly intervals on 60 shoots of cultivar Totapuri at five diverse locations for testing usefulness of scale under different diverse ecologies and data from one location, i.e., Lucknow (26o 54' N and 80o 48' E ) was used for analysis. Existing BBCH scale was modified on the basis of data recorded for mango in which seven out of 10 principal stages were used, starting with bud development (stage 0) and ending with maturity of fruit (stage 8). Three digit scale was used for inclusion of the mesostages between the principal and secondary growth stages. Highly recurring flowering phenophases were 511 (18 %), 513 (20 %) recorded in standard week 9 and 517 (45 %) in standard week 11 (March). Other important phenophases, 619 (38 %) and 709 (10 %) occured during standard weeks 13 and 22 to 23, respectively. A high degree of variation in shoots representing principal growth stages viz., vegetative bud, leaf and shoot development was observed due to simultaneous transition of the stages during standard week 33 to 42 and 4 to 24. Limitations of existing BBCH scale and comprehended modifications have been proposed and discussed. The study revealed that the extended BBCH-scale for mango can be widely used because of its utility in describing all phenophases pertaining to bud, shoot, leaf, panicle and fruit development and indicated the incisive growth pattern of the shoots and seasonal variation. This is the first report on quantitative analysis of mango phenological data using BBCH scale.
Hatem Mabrouk and Slah Mejri
Laboratoire d'arboriculture fruitiere. Laboratoire des Industries agro-alimentaires. Institut national Agronomique de Tunisie : 43, Avenue Charles Nicolle 1082 -Tunis-Mahrajene-Tunisie.
Key words: Japanese plum, Prunus salicina L., maturity, fruit quality, cold storage, Tunisia.
Abstract: Fruit Quality attributes of two Japanese plum (Prunus salicina L.) varieties 'Black Diamond' and 'Fortune' cultivated in Tunisia were monitored during fruit ripening on the tree and cold storage. A five years old commercial orchard was used for the study. Harvested fruits were stored in cold rooms at temperature less than 2?C and relative humidity around 90%. Beginning at two weeks before harvest, until the end of the cold storage period, samples of 20 fruits were taken at irregular time intervals and used for the determination of soluble solids concentration (SSC), titratable acidity (TA) and fruit firmness. At harvest, values of SSC were similar for both varieties reaching 15 and 14.8%, respectively for 'Black Diamond' and 'Fortune'. During cold storage, the increase in SSC was nil for 'Fortune' and very low (0.2%) for 'Black Diamond'. In contrast, values of TA were different for 'Black Diamond' and 'Fortune', the former was more acidic at harvest and during cold storage. TA values ranged between 0.94 and 1.24 % malic acid at harvest and 0.8 and 1% at the end of storage period. The sugar to acid ratio (SSC/TA) showed a continuous increase during ripening and cold storage for both varieties. Values of SSC/TA, differed largely between the two varieties, at all sampling dates. Fruit Firmness decreased during ripening and cold storage for both cultivars. At harvest 'Fortune' fruits were more firm (28.44 N) than 'Black Diamond' (21.77 N). At the end of cold storage, these values were as low as 10.64 N for 'Black Diamond' and 15.64 N for 'Fortune'. A linear regression analysis showed that the rate of firmness decrease during cold storage was very similar for both cultivar and reached a value of 0.23 N day-1. Thus, fruit firmness could be used to determine harvest time and to predict cold storage duration
H. Liang, YJ. Hu, W.M. Pang, W. Liu and M.X. Yang
College of Life Sciences, Zhongkai University of Agriculture and Engineering, Guangzhou, China.
Key words: Kiwifruit, radiation, top grafting, 60Co y-ray, breeding
Abstract: The aim of this study was to determine the feasibility of radiation treatment of the grafted buds in kiwifruit improvement. After treated with 50 Gy 60Co y-ray, buds from different fruit spurs of Actinidia were top grafted onto the heavily pruned mature vines with 50 -100 grafted buds per stock plants and the grafted plants were under intensive cultural practices for high survival rate of the grafting. The experimental results showed that treatment with 60Co y-ray increased SSR diversity and phenotypic variations of the kiwifruit canes produced from the grafted buds. Selection of the favourable variants from a large population (canes from different plants) in a limited area of kiwifruit orchard was possible and some of favourable variants from the grafted populations were selected and rapidly propagated for further utilization in kiwifruit improvement.
P. Youryon, C. WongsAree, W.B. McGlasson, S. Glahan and S. Kanlayanarat
Postharvest Technology Program, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand. Postharvest Technology Innovation Centre, Commission on Higher Education, Bangkok 10400, Thailand. University
Key words: Ananas comosus, CAM plant, fruit acidity, harvesting time, black heart
Abstract: Pineapple plants cv. 'Trad-Srithong' (Ananas comosus L.) were found to exhibit crassulacean acid metabolism (CAM). The concentrations of organic acids were higher in mature crown and stem leaves harvested at 0600 than at 1200 h but there were no significant differences in acid concentrations among fruit harvested at these times. Fruit of 'Trad-Srithong' (Queen group) are highly sensitive to internal browning (IB), a form of chilling injury, when stored at <15 ?C. Fruit were harvested at 0600 and 1200 h and stored at 8, 13 and 20 ?C. IB developed in fruit stored at 8 and 13 ?C after 10 days but no symptom developed in control fruit stored at 20 ?C. Time of day, when the fruit were harvested had no effect on the development of IB in 'Trad-Srithong' fruit. TA increased in fruit during storage at all temperatures. Juice extracted from the pulp had higher TA and lower pH than the core tissue and symptoms of IB were more severe in the flesh surrounding the core. Ascorbic acid decreased late during storage period.
K. Nagaz, K. Khlouj, I. Toumi, F. El Mokh, M.M. Masmoudi and N. Ben Mechlia
Institut des Regions Arides, 4119 Medenine, Tunisia. INAT, 43 avenue Charles Nicolle, 2083 Tunis, Tunisia.
Key words: Potato, salinity, nitrogen, yield, water use efficiency, arid
Abstract: Field studies were conducted on a sandy soil during spring of 2004 and 2007 in an arid region of southern Tunisia to determine the effect of water quality and nitrogen on yield, yield components and water use efficiency (WUE) of "Spunta", a potato (Solanum tuberosum L.) cultivar. Irrigation water of two qualities viz., canal water (3.25 dS m1) and saline water (5.2 dS m1) was used. Nitrogen was applied at the rate of 0, 100, 200 and 300 kg ha-1. For all treatments, irrigations were scheduled when readily available water in the root zone (35% of the total available water) was depleted. Yield, yield components, water supply and soil salinity were measured. Findings are globally consistent between the two experiments. Results showed that soil salinity values remained lower than those of ECiw and were lowest under emitters and highest midway to the margin of wetted bands. Potato yield significantly decreased under the use of saline water. The reduction in potato yield was mainly attributed to reduction in the number of tubers per m2 and tuber weight. WUE decreased significantly with increasing irrigation water salinity. Potato yield, yield components and WUE increased with an increase in nitrogen rates. The N application rate of 300 kg ha-1 gave good yield and higher WUE of potato in Southern Tunisia.
Waseem Shahri and Inayatullah Tahir
Plant Physiology and Biochemistry Research Laboratory, Department of Botany, University of Kashmir, Srinagar-190006, India.
Abstract: A study was conducted to examine the effects of pulse treatment with different concentrations of cycloheximide (CHI) on postharvest performance of cut spikes of Consolida ajacis cv. Violet Blue in distilled water and sucrose 0.2 M+HQS 100 mg/L. The present investigation revealed that at a particular threshold concentration (0.01 mM), it delays senescence and above that it prevents flower opening and promotes senescence. Cycloheximide at 0.01 mM concentration enhanced vase life, besides maintaining higher fresh and dry mass of flowers and soluble protein content in the sepal tissue. The fact that cycloheximide delays petal/sepal senescence demonstrates that the synthesis of particular suicide proteins, probably enzymes responsible for degradation of cellular constituents, orchestrates the cell death programme. Postharvest performance of spikes was much better in spikes pretreated with 0.01 mM CHI and transferred to sucrose+HQS and this can be used as an effective treatment to improve postharvest longevity in this flower system.
N.R. Bhat, H. AlMenaie, M. Suleiman, LAlMulla, B. Thomas, P. George, S. Isat Ali and G. D? Cruz
Kuwait Institute for Scientific Research, P. O. Box 24885, 13109 Safat, Kuwait.
Key words: Olive, evapotranspiration, cultivars, adaptability, deficit irrigation, water stress
Abstract: The ability of olives to adapt harsh environmental conditions makes its cultivation possible where plants are frequently exposed to high temperatures and scarcity of water. As the annual crop evapotranspiration far exceeds the rainfall in Kuwait, supplemental irrigation is essential for plant production. Under this conditions, efficient irrigation strategy is crucial for sustainable olive production. Therefore, the irrigation study comprising of five cultivars (Arbequina, Barnea, Coratina, Koroneiki and UC13A6) and three levels of irrigation (50, 75 or 100% of ETp) was conducted during 2006 - 2008. The results showed that none of the cultivars was adversely affected by even the highest water stress level (50% of ETp), indicating that these cultivars were able to tolerate severe and prolonged drought conditions. However, cultivar differences in plant height, stem diameter, number of branches and weight of pruned materials were significant at P < 0.01. Overall, cultivars Barnea and Coratina exhibited better adaptability to deficit irrigation and grew more vigorously than other cultivars. UC13A6 was most affected by the harsh growing conditions of Kuwait.
Prasann Kumar, Biswapati Mandal and Padmanabh Dwivedi
Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi-221005, India. department of Soil Science and Agriculture Chemistry, BCKV, West Bengal, India.
Abstract: The recent developments to identify or evolve high biomass crop plants having capabilities to accumulate heavy metals suggest that phytoremediation of metal contaminated soil can be a viable alternative to most conventional clean up technology. Comparative study of heavy metals concentration in the roots, shoots and leaves of different woody plants species e.g. Bougainvillea glabra, Croton spp, Quisqualis indica, Ficus benjamina Variegata, Toona ciliata, and Siris (Albizia lebbeck)indicated their high heavy metals scavenging capacity. For studying the heavy metal content of sewage sludge and plant species, solid sludge and plants were collected from seven Sewage Treatment Plants (STPs) viz., Howrah, Garulia, Bhatpara, Nabadwip, Srirampur, Kona, Chandannager, and from the Periurban areas viz., Nadia/Chakdaha/Ektapur (N/C/E), Pumlia (N/C/P), Sikarpur (N/C/S), Tatla (N/C/T). Sludge samples were taken from heaps at various places in the pile of each plant, using an auger. Around 6-10 individual samples were mixed together and pooled sample were used for analysis. The concentration of Cd, Pb, Cr, and Ni in the roots of plants at STP ranged from 0.805 to 1.03, 9.24 to 32.6, 10.62 to 15.56, and <0.05 mg kg-1, respectively. Whereas, Cd, Pb, Cr, and Ni content in the shoots of plants at STPs ranged from 1.55 to 1.7, 9.27 to 22.6, 5.35 to 11.03, and <0.05 mg kg-1, respectively. In the leaves, Cd, Pb, Cr, and Ni content ranged from 1.76 to 3.58, 9.1 to 22.76, 8.76 to12.02, and <0.05 mg kg-1, respectively. Therefore, above mentioned plant species can be selected for scavenging heavy metals from soils and sludges.
Dilip Kumar Mishra and L.P. Yadava
K.V.K., Kasturbagram, Indore, M.P. -452020, Central Institute for Subtropical Horticulture, Lucknow-227107, India.
Abstract: The effects of method of application and concentration of paclobutrazol on flower stalk length, flower size, flower longevity and yield of China aster were studied. Thiry five days old seedlings of China aster cv. Poornima were treated with paclobutrazol @ 0, 25, 50, 100 and 200 ppm through root dip, soil drench and foliar spray methods. Length of flower stalk and flower size significantly decreased with increased concentrations of paclobutrazol except in case of flower size when applied as foliar spray. Contrarily, flower longevity not influenced adversely with increased concentration of paclobutrazol, whether applied as root dip or soil drench or foliar spray. In each application method, flower yield was significantly higher at 25 ppm paclobutrazol. However, drench application of paclobutrazol was consistently more effective than foliar or root dip treatments with regard to length of flower stalk. Among the different levels and methods of paclobutrazol application, plants treated with 25 ppm as foliar spray proved to be superior over control and rest of the treatment combinations by increasing flower diameter and yield of cut flower as compared to control.
A.A. Waman, B.N. Sathyanarayana , K. Umesha, Balakrishna Gowda, T.H. Ashok, M. Rajesh and R.G. Guruprakash
Plant Tissue Culture Laboratory, Department of Horticulture, Department of Forestry and Environmental Sciences, Department of Plant Biotechnology, University of Agricultural Sciences, GKVK, Bengaluru-560 065, Karnataka, India.
Key words: Ashwagandha, Indian ginseng, In vitro, low cost options, medicinal plant, plant growth regulators, Withania somnifera
Abstract: Withania somnifera (L.) Dunal., one of the 32 prioritized medicinal plants of India, is well known for its importance in the Ayurveda system of medicine. Attempt was made to establish an efficient plant regeneration protocol for a commercial cultivar 'Poshita' and to acclimatize the plantlets ex vitro, so as to reduce the cost. Results revealed that shoot induction was possible only after an intervening callus phase, irrespective of the concentration of growth regulators present in the nutrient pool. Nodal explant cultured on MS media supplemented with 1 mg L-1 BAP + 0.5 mg L-1 NAA showed superiority in callus induction capacity over epicotyls and leaves. Nodal segments when cultured on a media containing BAP alone could induce shoots in cent per cent explants. Highest number of shoots (5.8) was obtained in media containing 2 mg L-1 BAP. Number of adventitious buds was found to be maximum (13) with epicotyl explant and 1 mg L-1 BAP combination. Nodal explants cultured on high concentration of BAP (4 mg L-1) showed highest incidence of malformed shoots (4.3). A total of 66.7 % plantlets could root and establish ex vitro even without auxin treatment and survival rate increased (87.5%) with increase in IBA concentration to 500 mg L-1. The present protocol can be exploited on a commercial scale to obtain maximum benefits from the improved cultivar. Furthermore, ex vitro hardening can help to reduce the cost of production and thereby make the tissue culture industry more profitable.
B. Anita, N. Selvaraj and R.M. Vijayakumar
Horticultural Research Station, Ooty, Nilgiris-643001, India.
Abstract: Protected cultivation is an emerging technology in Nilgiris for raising cut flower crops. Due to controlled environmental condition and continuous growing of crops, the root-knot nematode Meloidogyne hapla has emerged as a major problem in gerbera cultivation causing enormous yield loss. The damage progressively increases if proper sanitation control measures are not followed during the polyhouse cultivation. In the absence of Methyl Bromide, it is necessary to use other options. Biofumigation was evaluated to control soil borne nematode parasites with the aim to develop bio-pesticides, which could be effective against root knot nematodes without deteriorating soil environment. Two field trials were conducted to study the effect of combined use of biofumigants and bioagents on the nematode population. Mustard crop was ploughed in situ before flowering and covered with a plastic mulch for one month in polyhouses. The biocontrol agents viz., Pseudomonasfluorescens and Trichoderma viride were tried either alone or in combination with biofumigation. The stem length, flower yield and nematode population in soil were recorded. The study conducted at two different locations indicated that biofumigation with mustard followed by soil application of P. fluorescens @1.25 kg/ha at the time of planting significantly suppressed the population of M. hapla in soil by 67.5 to 67.8% and enhanced the flower yield of gerbera by 41 to 44%.
K. Umesha, G.R. Smitha, B.S. Sreeramu and A.A. Waman
Department of Horticulture, University of Agricultural Sciences, Gandhi Krishi Vignan Kendra, Bengaluru-560065, Karnataka, India. Directorate of Medicinal and Aromatic Plants Research, Boriavi, Anand-387 310, Gujarat, India
Abstract: The influence of different organic manures, bio-fertilizers and green manures on growth, yield and glycoside content of stevia (Stevia rebaudiana)was studied over a period of three years (2004-2007). Various organic supplements viz., farm yard manure (15 and 25 t ha-1), vermicompost (1 and 2 t ha-1), neem cake (0.5 and 1 t ha-1) and bio-fertilizers viz., Azospirillum, phosphorus solubilizing bacteria and VAM (each @ 0 and 10 kg ha-1) were applied. The results of eleven harvests revealed that all the growth parameters viz., plant height, number of branches and plant spread were influenced by various organics and bio-fertilizers and showed variation from season to season (harvest to harvest) and plants responses did not followed a definite trend. Dry leaf yield during first (6.16 t ha-1) and second year (4.34 t ha-1) of cropping was maximum with the treatment receiving FYM (25 t ha-1) + vermicompost (2 t ha-1) + neem cake (1 t ha-1) + bio-fertilizers (10 kg ha-1) and differed significantly. However, in third year of cropping the treatments had no significant influence on the dry leaf yield. Both the glycosides i.e., stevioside (7.8 %) and rebaudioside content (3.4 %), and glycoside yield were also highest in the above said treatment.
T Tworkoski, M. Wisniewski and T Artlip
USDA-ARS, 2217 Wiltshire Road., Appalachian Fruit Research Station, Kearneysville, WV25430, USA.
Key words: Abscisic acid, P-aminobutyric acid, dehydration, gas exchange, priming, water potential, Malus domestica
Abstract: Limited fresh water is a global problem that adversely affects crops, including young apple (Malus x domestica)trees. Innovative technologies will be needed to ensure tree survival and productivity. Recently, selected chemicals have been used to prepare plants for avoidance and recovery from water stress by a process termed priming. Two priming compounds, abscisic acid (ABA) and DL-P-aminobutyric acid (BABA) have been shown to confer plant protection against a range of biotic and abiotic stresses. Our objective was to determine the resistance to and recovery from dehydration of apple seedlings treated with s-ABA and BABA. Three greenhouse experiments were conducted in which combinations of s-ABA and BABA were applied as a root drench to one-year-old 'Royal Gala' apple trees and responses to dehydration were evaluated. Changes in leaf water potential (v|/w), stomatal conductance (gs), transpiration (E), leaf ABA and growth were measured during dehydration and rehydration. In two experiments, pretreatment with BABA reduced early morning E but BABA was not as effective as s-ABA in delaying dehydration-induced wilt of shoot tips. In another experiment during the second week without water both BABA- and s-ABA-treated trees had 42 to 62% higher leaf Y|/w, respectively, and 45% lower leaf ABA than unwatered controls. Higher leaf Y|/w was not consistently associated with reduced gs and E suggesting that mechanisms other than increased stomatal resistance may provide drought resistance. Compared with control trees, there was nearly 80% more shoot growth following rewatering after dehydration in trees that were primed with BABA and s-ABA (1.0 mM each). Leaf senescence was more evident in s-ABA- than BABA-treated trees and, although growth resumed after dehydration, the amount of growth varied with concentration of the priming treatments. Both individual compounds provided dehydration protection to young apple trees but in combination they were not clearly superior to either compound alone.
Simon J. van Donk, Dale T Lindgren, Daniel M. Schaaf, James L. Petersen and David D. Tarkalson
University of Nebraska-Lincoln, West Central Research and Extension Center, 402 West State Farm Road, North Platte, NE 69101-7751, USA.
Abstract: Wood chip mulches are used in landscapes to reduce soil water evaporation and competition from weeds. A study was conducted over a three-year period to determine soil water content at various depths under four wood chip mulch treatments and to evaluate the effects of wood chip thickness on growth of 'Husker Red' Penstemon digitalis Nutt. plants. The effects of four wood chip thicknesses (depth of application: 0, 2.5, 5, and 10 cm) on soil water content, weed numbers, soil temperature, and height, width, stalk number, and first flower date of 'Husker Red' Penstemon were investigated. The addition of mulch, at all mulch thicknesses, conserved soil water compared to when no mulch was used. The differences in soil water content likely influenced some of the plant growth factors measured. Weed numbers were significantly higher at 0 and 2.5 cm mulch thickness compared to 5 and 10 cm thickness. In general, mid-day soil temperatures were highest at the shallower soil depths in the unmulched plots. Flowering plants in 2008 in the unmulched treatment were slightly shorter than in the mulched treatments. There were no significant differences in the number of flower stalks per plant although there was a trend for a lower number of stalks with the mulched treatment. The time of first flower was, on an average, about 2 days earlier for the unmulched treatment compared to the 10 cm mulch thickness. Wood chip mulch helped conserve soil water, which in turn had some effects on plant growth.
University of Idaho, Parma Research and Extension Center, 29603. U of I Lane, Parma, ID-83660, USA.
Key words: Cold region table grapes, cultivar evaluation, grape genotype, grape adaptability, high desert table grape. Intermountain West region
Abstract: Long-term adaptability and feasibility of table grape production under the high desert conditions of southwest Idaho in the Intermountain West region of the United States were studied systematically in two phases. In the first phase, 'Alborz', 'Challenger', 'Italia', 'Emerald', 'Red Globe', 'Delight', 'Fantasy', 'Flame' and 'Fresno' (all Vitis vinifera L.) and NY36095, NY47616, 'Glenora', 'Reliance', 'Vanessa', 'Saturn', 'Jupiter' (hybrids of Vitis labrusca)had overall better berry quality and consumer preference than other tested grapes. In the second phase, 'Ralli' (also called 'Anahita' in the Intermountain West), 'Kashishi', and 'Autumn Royal' had excellent berry size and quality. 'Anahita' was harvested between Sept 1 and Sep 30. Both 'Kashishi' and 'Autumn Royal' were late-season grapes and matured between Sept 15 and Oct 15. 'Princess' was harvested between Sept 5 and Sept 30. This grape had outstanding flavour but the fruit set was low and clusters were small (268 g). 'Alborz' was harvested between Sept 1 and Sept 30, and with proper thinning, this cultivar had outstanding clusters and berries. Considering all viticultural and quality attributes, we recommend 'Alborz' as a potentially successful table grape for planting in small or large commercial scales under conditions of this study.
Lydia L.M. KitongaMwanza, John Swiader and Richard M.S. Mulwa
Egerton University, Department of Environmental Science, P. O. Box 536, Egerton, Kenya. Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana IL 61801. Egerton University, Department of Crops, Horticulture and Soils, P
Abstract: This study was conducted over two growing seasons to evaluate the potential use of the Minolta SPAD-502 chlorophyll meter for rapid onsite determination of plant N status in a drip-fertigated nitrogen cropping regime of sweet corn. Four N fertilizer rates (0, 84, 168, and 336 kg N ha-1) were applied to two sweet corn cultivars ('Kandy Plus' and 'Sugar Ace') in a factorial split-plot design. Leaf SPAD and leaf total N concentration were measured at 4 different growth stages (seventh leaf stage (V7), tenth leaf stage V10), silking (R1) and milking (R3) in season one and three sampling stages (V6, V10 and R1) in 2002. In season two, leaf N concentrations and leaf 'SPAD chlorophyll' measurements increased early in the season up to silking (R1 growth stage) and declined thereafter. Leaf N concentrations and leaf SPAD readings were positively correlated. Critical SPAD values (readings associated with the lowest N fertilizer rate and providing the highest marketable ear yield) were estimated as 52.8, 52.1 and 59.0 at V7, V10 and R1 in season one; in season two the values were 51.0, 49, and 56.5 receptively. Regressing N rate on yield placed maximum ear yields at 13.8 tons ha-1 with 174.8 kg N ha-1 in season one and 9.7 tons ha-1 with 306.2 kg ha-1 in season two. Increase in leaf SPAD readings at silking reflects a strong sink/source relationship among leaves for absorbed N. The positive relationship between leaf SPAD readings and leaf N status is due to the responsiveness of SPAD-chlorophyll to N fertilizer application. These results indicate that the SPAD meter can be used effectively to assess sweet corn N status early in the season, and at this time it is possible to correct any N deficiencies that might compromise yields.
Firdose Kolar, Nilesh Pawar and Ghansham Dixit
Laboratory of Cytogenetics and Plant Breeding, Department of Botany, Shivaji University, Kolhapur - 416 004.
Key words: D. malabaricum, mutagens: EMS, SA, gamma rays, chlorophyll mutants
Abstract: The phenotypic response of Delphinium malabaricum to chemical mutagens (EMS and SA) and physical mutagen (gamma rays) were studied. It was observed that D. malabaricum manifested specific reactions to the treatments with EMS, SA and gamma rays. Different mutation frequencies and width of mutation spectra were induced under the action of different concentrations of the applied mutagens. Eleven different types of chlorophyll mutants namely albina, albina-green, xantha, aurea, chlorina, viridis, yellow viridis, tigrina, striata, maculata and variegated type were identified in the treated populations and chlorophyll mutation frequency was calculated on plant population basis. Frequency of viridis mutants were highest followed by xantha and other types in all the treatments. The treatments of EMS were found to be more efficient than SA and gamma rays in inducing chlorophyll mutations. The highest frequency of chlorophyll mutations (9.74%) was reported in the 0.25% EMS. Quantitative estimation of chlorophyll pigments was also done in different kinds of chlorophyll mutants and chlorophyll content was found in the following decreasing order: chlorina > maculata> variegated> striata> tigrina> viridis> yellow viridis> albina green> aurea> xantha > albina. The study of induced genetic variability for frequency and spectrum of chlorophyll mutations is the first report in D. malabaricum.
Abstract: A powered walnut cracker is a device that does its job with a minimum of human effort. We offer a design consisting of an adjustable upper board, the lower board is replaced by chains or belts on which the nut is placed. The walnut moves, it touches the upper board and rotates while being cracked. The use of inexpensive bicycle parts is the advantage of this approach.
N. Kameswara Rao and Mohammed Shahid
International Center for Biosaline Agriculture, P.O. Box 14660, Dubai, UAE.
Abstract: The performance of asparagus (Asparagus officinalis L.) under the desert conditions of the Arabian Peninsula was evaluated. Ten cultivars introduced from six countries were studied. Two months old seedlings were transplanted into field plots in February 2007 and spears produced in the second year were harvested over a period of four weeks. Significant differences were found among cultivars for the number and quality of spears. The average number of spears harvested per plant varied between 5.0 and 26.4 and the spear yield between 36.3 and 159.2 g plant-1. The spear number and yield were highest in cultivar PI 277824. Seed yields from the first year of harvest varied from 29.7 to 136.2 g plant-1 among cultivars. In many cultivars, spear yields obtained in the second year were comparable to the yields reported from the productive environments in the tropics. The results show that asparagus has considerable potential for cultivation under the desert conditions of the Arabian Peninsula.
M. Manamohan, M.N. Prakash, G. Sharath Chandra, R. Asokan and S.N. Nagesha)
Corresponding author : Division of Biotechnology, Indian Institute of Horticultural Research, Hesaraghatta Lake PO. Bangalore-560089, Karnataka, India.
Abstract: Transformation of tomato with heterologous genes requires rapid and efficient transformation protocols. Agrobacterium mediated transformation protocol of tomato (Solanum lycopersicum L.) cv. 'Arka Vikas' using dreb1A gene under Rd29A promoter in pCAMBIA 2301 binary vector was optimized by varying parameters such as type of explant, type and concentrations of hormones. Hypocotyls were found to be the best explants for shoot regeneration in tomato compared to cotyledons with 53.2 and 22.8% shoot regeneration, respectively. In the shoot regeneration medium, 0.1 mgL4 IBA as a source of auxin gave nearly 50% higher shoot regeneration than IAA at similar concentration. With this protocol it was possible to obtain transformed plants within a period of 77 days with a high regeneration and transformation efficiency (34%) compared to over 120 days using earlier published protocols. The T1 generation plants segregated in a 3:1 ratio for the transgene and Southern blot analysis of the selected plants had shown the transgene integration was at a single locus. With this method it is possible to rapidly and efficiently generate transgenic tomato plants.
T.S. Rahi and Bajrang Singh
National Botanical Research Institute, Rana Pratap Marg, Lucknow, U.P., India.
Abstract: The scarcity of fertile land for growing ornamental crops has received attention on the utilization of salt affected soils for floriculture. Two cultivars of Chrysanthemum morifolium viz. 'Flirt' and 'Jayanti' were evaluated under three salinity levels (EC 4, 6 and 8 dS/m) of irrigation water along with control (irrigating with non-saline water). The experiment consisting of eight treatments with three replications was conducted in earthen pots with randomized block design. The pots were filled with sandy loam soil and 20 days old rooted cuttings were planted @ three cuttings per pot. The growth parameters viz., plant height, number of buds and flowers per plant; fresh and dry weight as well as chlorophyll content increased significantly with increasing salinity levels. 'Jayanti' appeared to be more salt tolerant in comparison to 'Flirt' in their floral morphology as well as in productivity. Nitrogen and phosphorus concentrations were reduced in plants as salinity increased. There was a relatively high N concentration in 'Flirt' cultivar. The concentration of other nutrients such as potassium, calcium and magnesium increased significantly with increasing salinity levels. This increase in nutritional uptake did not show any detrimental effect of Na toxicity in the salinized plants. As a result, nutrient use efficiency of nitrogen and phosphorus was enhanced with increasing salinity levels. Growth and flower yield both indicated that C. morifolium which is a plant of halophytic origin can be raised successfully as an ornamental cash crop in moderate saline environment, particularly 'Jayanti' cultivar. However, its critical limit to higher salinity tolerance is yet to be worked out.
Sunila Kumari, J.R. Desai and R.R. Shah
Department of Floriculture and Landscaping, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari - 396 450. Department of Horticulture, College of Agriculture, Indira Gandhi Agricultural University, Raipur-492 006, India.
Abstract: Plant regeneration of Anthurium andraeanum cultivars 'Pumasillo' and 'Corallis' has been achieved through adventitious shoots formation from callus. Young brown leaf lamina was used as explants for indirect organogenesis. These were disinfected using sodium hypochlorite (5%), ethanol (70 %) and HgCl2 (0.1%). The results showed that both the varieties responded differently to callus induction, callus proliferation and shoot initiation treatments. In 'Corallis', the maximum number of cultures initiated callus on Nitsch medium supplemented with 5 mgL-1 adenine and 2 mgL-1 BAP while in Pumasillo, maximum number of cultures initiated callus on modified MS medium supplemented with 5 mgL-1 adenine and 3 mgL-1 BAP. Maximum shoot regeneration was observed on modified MS supplemented with 0.01 mgL-1 TDZ in both the cultivars. Rooting medium was (modified half-strength MS salts) supplemented with 0.5 mgL-1 IBA and 0.04% active charcoals. The callusing frequency of 'Pumasillo' was higher as compared to 'Corallis'. Rooted plantlets were succesfully acclimatized in polythene covered plastic trays containing cocopeat. Later on the hardened plantlets were successfully transplanted to commercial potting medium (1:1:1:1 cocopeat: rice husk: sand: FYM ) and were transferred to poly house with survival rate of ninety per cent.
S.W. Goveas, S.K. Nivas and L.D. Souza
Laboratory of Applied Biology, St. Aloysius College, Mangalore-575003, Karnataka, India.
Key words: Selenicereus megalanthus, in vitro, yellow pitaya, multiple shoots, MS-Murashige and Skoog
Abstract: An efficient micropropagation system via multiple shoot induction directly from seedlings of S. megalanthus was developed. Seeds were germinated on Murashigae and Skoog (MS) basal medium supplemented with 6-Benzyl amino purine (BAP). The shoot tips of the germinating seedlings started callusing when left on the same medium. After two weeks, the entire shoot apex portion of epicotyl gave rise to a friable callus, portions of which started becoming green and morphogenetic. The callus gave rise to multiple shoots. The highest number of shoots i.e. 18.6 was produced on MS medium supplemented with 1.5 mgL"1 BAP. The shoots, 3-4 cm in length, when transferred to MS basal medium supplemented with 1.0 mgL-1 IBA, rooted within one week.
Adel D. Alqurashi
Faculty of Meteorology, Environment and Arid Land Agriculture, Department of Arid Land Agriculture, King Abdulaziz University, P.O.Box. 80208, Jeddah 21589, Saudi Arabia.
Key words: Date palm, pollen grain suspension, pollination, yield, fruit quality
Abstract: During 2008 and 2009 seasons, the effect of pollen grain-water suspension spray at different concentration on fruit setting, yield and quality of 'Helali' date palm cultivar growing under Hada-Alsham conditions, KSA was examined. The results showed that fruit set, bunch weight and total yield per tree were significantly higher when spray pollinated at 0.5, 1.0 and 1.5 g L-1 than the traditional pollination. In this respect, there were no significant differences among spray pollination at 0.5, 1.0 and 1.5 g L-1. However, spray pollination at 2.0 g L-1 gave fruit set percentage similar to traditional pollination. At harvest, the Rutab percentage in bunches was not affected by the method of pollination. At both the Bisir and Rutab stages, fruit, flesh and seed weight, diameter and length were not significantly affected by any of the pollination treatments. The biochemical characteristics of fruit such as TSS, acidity, vitamin C, total phenols and soluble tannins were not significantly affected by any of the pollination treatments at both stages. The concentrations of TSS and acidity were higher at the Rutab than at the Bisir stage. However, the concentrations of vitamin C, total phenols and soluble tannins were greatly lower at the Rutab than at the Bisir stage. This study showed the possibility to pollinate 'Helali' date trees by pollen grain-water suspension spray with optimum amount of pollen grains with no further need for thinning especially under hot arid conditions. However, more research work is required to standardize the optimum concentration of pollen grain-water suspension and the response of each date palm cultivar to this pollination technique.
S. Zivdar, E. Khaleghi and F. Sedighi Dehkordi
Department of Horticulture Science, College of Agriculture, Shahid Chamran University, Ahwaz, Iran.
Abstract: Laboratory studies were conduced to determine the effect of salinity and temperature on seed germination of zinnia plant with two temperature regimes (25 and 30 oC) and 5 levels of salinity (distilled water as control and 3, 6, 9 and 12 dSm-1) in a factorial completely randomized design. Analysis of variance showed significant difference (P<0.05) between different levels of salinity, and salinity and temperature interactions on germination percentage, germination rate and length of rootlet. But temperature treatment only influenced rootlet length (P<0.05). Mean comparison of seed germination percentage showed that increasing salinity decreased the seed germination. The highest rootlet length was recorded in the control (8.273 cm) and the lowest (1.92 cm) was at 12 dSm-1 of salinity. The effect of temperature on the germination percentage, germination rate and length of rootlet determined that the highest germination percentage and length of rootlet was at 25 oC temperature. The study on the interaction of temperature and salinity exhibited that highest percentage of germination, germination rate and length of rootlet were in control at 25?C, whereas it was lowest at 30?C and 12 dSm-1 salinity.
Pooja Manchanda, Ajinder Kaur and Satbir Singh Gosal
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiasna, Punjab -141004, India.
Abstract: This is the first report of antibacterial and growth promoting effectiveness of cefotaxime in banana tissue culture. Young suckers (3-13 cm diameter) of commercially important banana varieties viz., 'Grand Naine' and 'Robusta' were regenerated into shoots on MS-medium supplemented with 6-benzylaminopurine (BA, 5 mgL-1) and multiplied on Banana Multiplication Medium (BMM) for 7 cycles of 3 weeks each. Shoots were separated and cultured on BMM supplemented with IBA (1.0 mgL-1) and cefotaxime at various concentrations viz., 0, 100, 200, 300, 400, 500, 600 and 700 mgL1. Maximum shoot multiplication and elongation with respect to number of shoots, shoot length and plantlet fresh weight in both the genotypes was obtained with cefotaxime used at the rate of 400 and 500 mgL-1 in the medium. Among the different varieties, on the basis of mean of 50 shoot cultures, number of shoots per culture and shoot length was highest in cv. Robusta i.e. 7.20 (41.6% increase over control) and 8.50 cm (30.5% increase over control), respectively. Whereas, plantlet fresh weight was highest in cv. Grand Naine (494.8 mg, 38.9% increase over control) after 3 weeks of culturing with cefotaxime used at the rate of 500 mgL-1. Results revealed significant differences among varieties and media for different shoot multiplication and elongation parameters. Therefore, use of cefotaxime during tissue culture and genetic transformation of banana can improve frequency of shoot multiplication and transformation, respectively.
Y.A. ALKamal, A.I. Abdalla and A.A. Taha
University of Al Zaeim Al Azhari -Faculty of Agriculture, Khartoum North - P.O. Box 1432- Sudan
Key words: Abelmoschus esculentus, okra, combining ability, line x tester analysis
Abstract: Seven lines of okra Abelmoschus esculentus [L.] (MOENCH) were evaluated for general and specific combining ability using three diverse testers following a line x tester mating design as described by Kempthorne (1957). Twenty one F1's hybrids along with ten parental lines were raised at the Demonstration Farm of the Faculty of Agriculture, University of Al Zaeim Al Azhari, Sudan, using randomized complete block design with three replications. Analysis of variance revealed significant differences among genotypes existing for yield and associated traits (P=0.01), indicating the presence of sufficient genetic variability in the material studied. Significant variability existed among hybrids (P=0.01) for number of pods per plant, length of pod, pod yield per plant and 100 seeds weight. Estimation of general combining ability effect identified lines HSD 1835, HSD1840 and HSD 2550 as a good general combiners for pod dry weight (P=0.05). Among testers Sinnar was found to be a good general combiner for number of pods per plant, length of pod, yield per plant, number of seed per pod and 100 seeds weight. Estimation of specific combining ability effect identified hybrids HSD 2550 x Sinnar as the best parent combination for number of pods per plant and yield per plant. HSD2543 x Sinnar and HSD1840 x Clemson Spineless recorded as the best parental combination for length of pod. The additive as well as non-additive gene effects played significant role in the inheritance of yield and yield related traits with predominance of additive gene action in the inheritance of major yield contributing traits. Testers contribution percentage were significantly higher for number of pods per plant (77.04%), pod dry weight (40.06 %) and number of seeds per pod (45.04%). The percentage contributions of the interaction were significantly higher and evident in the rest of the traits.
J.O. Olaniyi and M.A. Ajao
Department of Agronomy, Faculty of Agricultural Sciences, Ladoke Akintola University of Technology, P.M.B 4000, Ogbomoso, Oyo State, Nigeria.
Abstract: Field experiments were conducted at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso (8o 10'N and 4o 10'E) to determine the effect of mulching materials and rates of NPK fertilizer application on the growth and yield of fluted pumpkin (Telfairia occidentalis). The trials consisted of three levels (0, 250 and 350 kg ha1) NPK and four types of mulching materials (white polyethylene, black polyethylene, saw dust and Panicum grass). A factorial arrangement fitted into complete randomized block was used and replicated three times. Plant height and number of leaves increased as the NPK rate increased, irrespective of the mulching materials. The yield and yield components of telfairia increased as the NPK rate increased from 0 up to 250 kg ha-1 and then declined at 350 kg NPK ha-1. These were significantly (P<0.05) improved by the main effects of fertilizer and mulching materials. Although, the best performance of telfairia in term of yield and quality were obtained from white polyethylene mulching material, this was comparable with that of dry Panicum grass mulching material. Except for fibre and vitamin C contents, telfairia seeds contained higher quality attributes investigated under this study than leaves. Therefore, the yield and quality of telfairia could significantly be improved by the application of NPK fertilizer at the optimum rate of 250 kg ha-1 with and without mulching.
N.K. Rao and Mohammed Shahid
International Center for Biosaline Agriculture (ICBA), P.O. Box 14660, Dubai, UAE.
Abstract: The performance of Gaillardia aristata Pursh, irrigated with saline water was studied with the objective to identify herbaceous ornamentals for saline landscapes. Seeds were sown directly into field plots of sandy soil and irrigated with saline water at electrical conductivity (ECW) of 2 (control), 5, 10 and 15 dSm-1. Increase in salinity reduced the plant stand by 38% at 5 dSm-1, 50% at 10 dSm-1 and 67% at 15 dSm-1, in comparison with the control. Increased salinity also decreased the mean height, number of branches and dry weight of the plants, but the differences among treatments lower than 15 dSm-1 salinity were statistically insignificant (P>0.05). Compared with the control, the number of flowers per plant declined by 57% at 5 dSm-1, 61% at 10 dSm-1 and 67% at 15 dSm-1. The differences in flower production among 5, 10 and 15 dSm-1 treatments were not significant (P>0.05). The flower diameter was significantly reduced at 15 dSm-1, but was not affected at the lower salinities. The results show that G. aristata could be successfully cultivated upto irrigation water salinity level 10 dSm-1 in sandy soils.
M.D.J.S. Saparamadu, W.A.P. Weerakkody, R.D. Wijesekera and H.D. Gunawardhana
Department of Chemistry, University of Colombo, Colombo 03, Sri Lanka. Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka.
Key words: Hydroponics nutrients, tomato, hydroponics in tropics
Abstract: Simplified hydroponics is a low cost aggregate hydroponics system which is practiced under natural climatic conditions with hand watering. Rice hull, a waste material, which is mostly under utilized and a mixture of rice hull and sand (3:2) was used in this system. A new nutrient formulation (NF) was developed using locally available commercial grade chemicals. A buffer system was incorporated to the nutrient formulation, ensuring that the pH was maintained in the optimum range. NF was composed of (in ppm), N = 167, P = 80, K = 281, Ca = 234, Mg = 57, S = 251, Cu = 0.01, Fe = 3.9, Zn = 0.13, Mn = 1.2 and Mo = 0.13. A field trial was carried out for NF in the wet zone in Sri Lanka for tomato plants in simplified hydroponics system. The nutrient uptake was monitored by measuring the changes in weekly average electrical conductivity (EC) of the root solution (compared to the EC of the applied nutrient) of tomato plant beds. The pH of the root solution was in the suitable range and no adjustment was required indicating sufficient buffering in the formulation. The nutrient cost involved to produce 1 kg of tomato was about 70% less than other commercially available nutrients formulation.
M. Prabhakar, S.S. Hebbar and A.K. Nair
Division ofVegetable Crops, Indian Institute of Horticultural Research, Hesaraghatta Lake, Bangalore-560089,Karnataka, India.
Key words: Organic farming, French bean, nutrients, growth and yield parameters, yield
Abstract: A field experiment was conducted during 2007-2010 to study the effect of levels of organic manure and conventional practices on growth and yield of French bean grown organically. The trial was carried out in organic experimental block of IIHR farm, Hesaraghatta, Bangalore. The trial included four levels of organic manure nutrient and two inorganic nutrient supply treatments. The treatment which received 100 per cent recommended dose of N (RDN) through organics produced the highest pod yield (17.77 t/ha) followed by treatments which received 75 per cent RDN through organics and conventional practices (17.45 and 15.93 t/ha). Plant growth parameters such as plant height (45.5 cm), number of leaves per plant (42.9), leaf area per plant (2706 cm2), nodules per plant (43.9), pod weight per plant (160.1g) and pod length (14.7 cm) were also comparatively higher in this treatment resulting in better pod yield. Application of recommended dose of chemical fertilizer in conjunction with farm yard manure recorded higher values for growth and yield parameters like number of leaves, leaf area, dry matter production, number of pods, pod weight per plant and pod length which also resulted in significantly higher pod yield as compared to the treatment which received recommended dose of chemical fertilizer only.
R.K. Singh, S.R. Bhonde and R.P. Gupta
National Horticultural Research and Development Foundation, Chitegaon Phata, Post-Darna Sangavi, Taluqa-Niphad, Nashik, 422 003, Maharashtra, India.
Key words: Allium cepa, correlation, late kharif, heritability, onion, variability
Abstract: An investigation was carried out to study the genetic variability in late kharif germplasm of onion at Nashik, Maharashtra (India). The mean data indicated that the highest gross yield (41.17 t/ha) and marketable yield (39.13 t/ha) was recorded in line 744 and was at par with line 682 (39.07 t/ha) and (34.39 t/ha). A wide range of variability was observed for gross yield (19.65 to 41.17 t/ha), marketable yield (10.05 to 39.13 t/ha), bulb size index (20.40 to 35.90 cm2), bolters (0.00 to 40.83%), doubles (0.00 to 47.50 %), thrips/plant (8.75 to 25.80) and plant height (54.95 to 71.80 cm). A higher magnitude of coefficient of variation was recorded for bolters (112.78 -112.65%), followed by doubles (86.35-86.16%), thrips/plant (37.55-37.36) and marketable yield (29.34 and 29.90 %). Highest heritability was noted in doubles, gross yield, bulb diameter, plant height, bolters and thrips/plant. The genetic advance as percent of mean ranged from 3.93 to 231.73. High genetic advance noted in bolters (231.73 %), doubles (177.12 %), thrips/plant (76.56%) and marketable yield (54.53%) and rest of others characters showed medium to low genetic advance. Gross yield, marketable yield, doubles, bolters, thrips/plant and bulb size index indicated higher estimates of genetic advance as percent of mean coupled with high heritability, suggesting the involvement of additive genetic variance for these traits. Marketable yield was significantly and positively correlated with plant height, neck thickness, bulb diameter, bulb size index, weight of 20 bulbs, and gross yield and negatively correlated with bolters, doubles and days for bulb initiation at genotypic and phenotypic levels. Plant height, leaves/plant, bulb diameter, bulb size index, weight of 20 bulbs and days for bulbs initiation. The study revealed that a wide range of variability for important characters exists in germplasm offering a good scope for developing improved onion varieties suitable for cultivation in Maharashtra.
Iniobong Edet Okon and Edet A. Imuk
Department of Botany, University of Calabar, Calabar, Nigeria. Department of Soil Science, University of Calabar, Calabar, Nigeria.
Abstract: The effect of Glomus fasciculatum inoculation on the growth and yield of tomato (Solanum lycopersicum L.) in a Meloidogyne incognita infested soil was investigated in a pot experiment. G. fasciculatum greatly enhanced the growth and yield of tomato in both non-nematode and nematode infested soils. Growth was greatly impeded to the point of no flowering or fruiting in non-mycorrhizal nematode infested soil treatments. While the adverse effect of nematode to the growth of tomato can be attributed to impaired transport of water and nutrients, the enhanced growth in mycorrhizal plants was associated with increased water and nutrient uptake, resulting improved growth which must have conferred more vigour on them to reduce the pathogens' effect.
Mar?a Pescie, Marcelo Lovisolo, Alberto De Magistris, Bernadine Strik and C?sar L?pez
Facultad de Ciencias Agrarias - Universidad Nacional de Lomas de Zamora, Ruta 4, Km. 2. (1836). Llavallol - Pvcia. de Buenos Aires, Argentina. Department of Horticulture, Oregon State University, 4017 ALS, Corvallis, OR 97331, USA.
Key words: Vaccinium sp., southern highbush blueberry, flower bud initiation, flower bud differentiation, day length, temperature
Abstract: In Argentina, southern highbush blueberry (Vaccinium sp.) exhibits two periods of vegetative growth in the same year, the first one in spring (spring growth, SpG), arising from vegetative buds on one-year-old wood, and the second in summer, from vegetative buds formed on spring growth, just after harvest (summer growth, SmG). Histological studies confirmed that flower bud initiation (FBI) occurred at the end of December on SpG and at the end of March on SmG. On SmG, FBI occurred under an 8 h photoperiod, and shortening daylength. However, on SpG, FBI was observed under increasing daylength (up to 15 h) and an average temperature of 22.5 ?C. Basal florets in apical floral buds were always in a more advanced reproductive stage on SpG than on SmG during the season. The two peaks in volume of fruit harvested were likely a result of differences in the ontogeny of buds on SpG and SmG shoots in the previous year.
J. Shankara Swamy and A.K. Banik
Department of Post Harvest Technology, Bidhan Chandra Krishi Viswa Vidhyalaya Mohanpur, West Bengal-741 252, India.
Abstract: Guava (Psidium guajava), called as apple of the tropics, is one of the most common fruits in India. Excellent flavour and nutritive value aid to its great potential for preparation of beverages like squash and ready to serve (RTS). A study was undertaken to produce a stable and organolepticaly preferred guava squash with proper suspension of fruit pulp supplementing the squash soluble dietary fibre with xanthan gum at five different concentrations (0.1 to 0.5%). Bottled guava squash of cv. Allahabad Safeda was prepared with 25% pulp, 40% total soluble solids (TSS), and 1% acidity with different concentration levels of xanthan gum, an exocellular polysaccharide produced by obligatory aerobic microorganism, Xanthomonas campestris. The stability of the products was studied by chemical and sensory evaluation of bottled squash during 180 days of storage. There were little changes in the quality parameters viz., TSS, pH, titratable acidity and ascorbic acid during storage. Non-enzymatic browning in guava squash increased with prolonged storage. Xanthan gum (0.5% W/W) gave stability to the product during 180 days of storage. Overall, acceptability was highest in pure guava squash containing 0.1% of xanthan gum, 40% of TSS and 1% of acidity during the 180 days of storage period.