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  • ThesisItemOpen Access
    Divergence studies in pumpkin (Cucurbita moschata Pair)
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1989) Suresh Babu, V; KAU; Gopalakrishnan, T R
    The present investigation on "Divergence studies in pumpkin (Cucurbita moschat a Poir ) was conducted at the College of Horticulture , Vellanikkara, Trissur during June 1988 - Marc h 1989. Seventy one pumpkin genotypes collected from different part of India and abroad were utilized for the study. The extent of variability and divergence among 50 selected genotypes were assessed and grouped into 5 clusters based on Mahalanobis D2 statistic . Cluster I, II, III, I V and V contained 2, 7, 9, 12 and 20 genotypes respectively y . Intercluster distance was maximum between clusters I and II and was minimum between clusters III and V . Cluster I showed maximum average intercluster distance with any other cluster. Screening 71 genotypes for resistance/ tolerance to pumpkin mosaic and yellow vein mosaic diseases revealed that all genotypes except C M 214 were susceptible. Artificial inoculation studies confirmed immunity of C M 214 (Nigerian Iocal ) to pumpkin mosaic virus and yellow vein mosaic virus .
  • ThesisItemOpen Access
    Effect of growth regulators on flowering pollination and seed-set in ginger(zingiber officinale, rose)
    (Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 1984) Usha, K; KAU; Balakrishnan, S
    Flowering behaviour and floral biology of Rio-de-Janeiro and Maran and the effect of growth regulators viz., kinetin (5, 10 and 15 ppm), Ethrel (25, 50 and 100 ppm) and NAA (10, 25 and 50 ppm) in combination with two per cent urea and without urea on flowering, pollination and seed-set in Rio-de-Janeiro were studied at the College of Horticulture, Kerala Agricultural university, Vellanikkara during 1981-’83. The objective of the investigation was to assess the available varieties of ginger for flowering behaviour and to evaluate the effect of growth regulators with and without urea on the flowering behaviour, floral biology, floral structure, pollination and seed- set in Rio-de-Janeiro. (The possibility of overcoming the problems of shy and irregular flowering, poor pollen germination and the failure to set seeds also was explored during the investigation). (Among the 25 varieties studied, flowering was observed only in two varieties viz., Rio-de-Janeiro and Maran). Considerable variation was noticed between Rio-de-Janeiro and Maran with respect to flowering behaviour, extent of flowering, types of inflorescence, time taken for scape development, anthesis, anther dehiscence, pollen production, pollen fertility, style length and ovary length. Long but thin style was noticed both in Rio-de-Janero and Maran. Irrespective of the variety, flowers were found to rot/ and dry within 16 hours after flower opening. The maximum pollen germination (6.20 per cent) was obtained in the medium containing eight per cent sucrose, three per cent gelatin and 60 ppm boric acid under moist cotton covering in BOD incubator (26.50C). Coiling of the pollen tube during the advanced stages of growth was noticed. Pollination carried out in Rio-de-Janeiro and Maran employing the variables like stage of flower (bud stage, immediately after flower opening and three hours after flower opening), condition of stigma (partial and complete removal of style), density of pollen (smearing once, twice and thrice with standard brush), mixed pollen (ginger pollen with either Alpinia, Hedychium, Kaempheria or Costus pollen) and supplementary pollination (repeated pollination twice at two hours interval) failed to record any positive evidence of seed-set. Effect of growth regulators and urea on flowering behaviour, inflorescence characteristics and floral structures of ginger was evidenced during the study. ( Favourable influence of NAA 50 ppm on inducing early flowering, kinetin 15 ppm on the duration of flowering, NAA and kinetin on inflorescence production, NAA 50 ppm without urea on the number of flowers per inflorescence, NAA 10 ppm and all the three levels of kinetin on pollen production, NAA on pollen diameter, higher levels of Kinetin and Ethrel and lower levels of NAA on exine thinning, Ethrel 25 ppm in combination with urea, Kinetin 15 ppm with urea, NAA 50 ppm and Kinetin 10 ppm on pollen fertility, lower levels of Kinetin and Ethrel on reducing the style length, Kinetin 15 ppm and NAA 10 ppm on ovary length, Ethrel 25 ppm with urea and higher levels of NAA and Kinetin on pollen germination and NAA 50 ppm on pollen tube growth was revealed during the study.) Floral biology of Rio-de-Janeiro was not influenced by growth regulator and urea treatments. Abnormal floral structures occurred as isolated cases and therefore the role of growth regulators and urea in this respect was not clear from the results. (Pollination carried out in ginger (var.Rio-de-Janeiro) plants, subjected to growth regulator treatments with and without urea, employing the variables like stage of flower, condition of stigma, density of pollen, mixed pollen and supplementary pollination failed to result in seed-set.)
  • ThesisItemOpen Access
    Screening for resistance to aphis craccivora in vegetable cowpea and evaluation of early types
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1984) Sulochana, K A; KAU; Peter, K V
    Cowpea Vigna unguiculata (L) walp is an important legume grown both in tropics and sub tropics. Eighty three cowpea lines were evaluated for field resistance to Aphis craccivora. All the lines except 10 TVU lines were infested by the aphid before 30 days after sowing. The lines TVU 1889, TVU 408, TVU 2896 and TVU 2962 were completely free from aphid infestation observed on leaves internodes and pods upto 60 days of sowing during the first crop season. The resistance reaction observed during second crop season and under controlled aphid infestation revealed that TVU 1889 was the most promising as far as aphid resistance is concerned. There are considerable variability in the cowpea for different characters and the lines K 1552 and TVU 1892 were the earliest to harvest (52 days). Among the weather parameters average number of rainy days and relative humidity had negative relationship with aphid population. Fifteen selected varieties of vegetable cowpea were grown in two seasons under two fertility levels. There were considerable variability in the vegetable types of cowpea for earliness which is important for the crop to be fitted in a multiple cropping system. The variety K 1552 was the earliest (52.13 days) followed by K 868 (52.43 days). The line IIHR 6-1-B is the most average stable variety with the highest mean (62.35 g) and bi value tending to one (0.96). The varieties K 1552, VS 89 and K 868 were high yielders but had bi value more than one and are suited for high yielding environments. The chemical analysis of pods for monosaccharides to polysaccharides ratio indicated that the yard long bean had the highest ratio followed by K 1552, IIHR 6-1-B and VS 87.
  • ThesisItemOpen Access
    Effect of gamma irradiation in ginger
    (Department of Horticulture (Plantation Crops and Spices), College of Horticulture, Vellanikkara, 1984) Giridharan, M P; KAU; Balakrishnan, S
    Investigation was carried out at the College of Horticulture, Vellanikkara, during 1983 – 84, to study the effect of gamma irradiation on germination, vegetative growth, flowering, yield, quality attributes and incidence of soft rot disease in ginger using four doses of gamma rays (0.7, 1, 1.5, 2.k rad). Irradiation treatments produced inhibitory effects on the germination of ginger rhizomes. The plant height, tiller production, leaf production, leaf size and leaf area index decreased with the increase in irradiation dosages. Flowering behaviour of ginger could not be altered by the levels of gamma irradiation tried. Rhizome yield reduced as the irradiation dose increased. The treatments did not differ significantly with regard to essential oil and oleoresin content of both green and dry ginger ; oleoresin of ginger peel and percentage recovery of dry rhizomes. However, the incidence of soft rot disease could be highly reduced by gamma irradiation.
  • ThesisItemOpen Access
    Evaluation of a set of non-segragating and segragating populations of tomato for field resistance to bacterial wilt
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1985) NarayananKutty, C; KAU; Peter, K V
    Bacterial wilt caused by Pseudomonas solanacearum E.F. Smith is the single limiting factor for tomato cultivation in the warm humid tropical soils of Kerala. The susceptibility of reportedly resistant varieties elsewhere necessitates the need for continuous evaluation of tomato lines for wilt resistance. An experiment was planned and carried out during 1983-’85 at the College of Horticulture, Vellanikkara to identify new sources of resistance to bacterial wilt. The susceptible check Pusa Ruby showed 100% susceptibility in all the trials. The F2 hybrids of Saturn and LE 79 were found resistant, out of the four non-segregating (Saturn, LE 79, Pusa Ruby and Pusa Ruby x LE 79 F1) and two segregating populations (Pusa Ruby x LE 79 F2, Saturn x LE 79 F2) evaluated. In a repeated trial F3s were also evaluated along with the F2s and non-segregating populations (Saturn and FE 79). Resistance was observed in Saturn x LE 79 F3 (percentage wilt, 10.7) and Saturn x LE 79 F2 (percentage wilt, 18.23). Pusa Ruby x LE 79 F2 s and F3s were susceptible to moderately susceptible. Among the non-segregating populations, LE 79 showed moderate resistance, while Saturn was moderately susceptible to susceptible in both the trials. Information on days to fruit set, days to harvest, fruit yield/plant and average fruit weight were also gathered. A higher average fruit weight (44.63g) was observed in the resistant Saturn x LE 79 F3s. Evaluation of 15 reportedly resistant lines of tomato confirmed resistance in LE 79 LFG and LE 217. The line LE 79 LFG was also medium fruited (40.1g) and high yielding. Concentric cracking and irregular cracking were observed higher than radial cracking in all the lines evaluated. Fruit set ranging from 50 to 63% was observed in all the lines at higher night temperatures (230C average). Genetics of fruit shoulder colour revealed that white colour was recessive to green and governed by a single gene. Evaluation techniques like root dipping in bacterial culture and planting, stem inoculation in leaf axil and alternate row planting were compared with spot-planting for efficiency. Spot-planting was found easier and effective. The chances for escape are negligible in this method of evaluation.
  • ThesisItemOpen Access
    Radiation induced variability in interspecific hybrids involving abolmoschus esculentus moench and abolmoschus manihot
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1986) Dalia Cherian; KAU; Peter, K V
    Yellow vein mosaic is the most destructive viral disease of bhindi, which takes heavy toll of the crop, infecting at all growth stages. Attempts to isolate source(s) of resistance to yellow vein mosaic disease from cultivars and wild relatives were proved to be of limited success because of either incompatibility or sterility barriers between the cultivars and wild relatives. An experiment was planned and carried out during June - October,1984; November - April, 1984-'85 and June - October 1985 at the Instructional Farm _ of the College of Horticulture, Vellanikkara, Trichur to induce variability in interspecific hybrids involving Abolmoschus esculetus (L.) Moench and Abolmoschus manihot (L.) Medic. The three accessions of Abolmoschus manihot were observed cross compatible with Abolmoschus esculentus cv. ‘Pusa Sawani', Abolmoschus menihot sap, tetraphyllus crossed readily with abolmoschus esculentus (Cl = 95%) . This was proved through Fo fruit set, Fo seed set and germination of F0 seeds. The F1 plants did not bear normal seeds and F2 generation could not be raised. The pollen fertility of F1 hybrids were much lower than the parents. There was reciprocal difference in the crossability index. radiation created considerable variability in interspecific F1 hybrids for days to flower, plant height,leaf length, leaf width, fruit length, fruit girth, nodes on main stem, fruiting nodes on main stem, intemodal length, fruits/plant, ridges/fruit and fruit yield/plant, in Abolmoschus esculentus x 2 accessions of Abolmoschus manihot. There was preponderance of characters of Abolmoschus manihot in the interspecific hybrids. Considerable changes in discrete characters were observed in irradiated F1 hybrids. Dominant characters like branched habit, pubescence and pigmentation of vegetative parts, and hairiness of fruit got changed with gamma radiation. Though the radiation enhanced the pollen fertility of interspecific hybrids, they had seedless fruits or fruits with incompletely filled seeds. With the doses 15 kR, 20 kR and 25 kR tried, quantitative and qualitative characters were affected, though there appeared to be scope for the use of still higher dose of rays to create wider variability in interspecific hybrids. Under natural field conditions and artificial inoculation, ‘Pusa Sawani’ was infected by yellow vein mosaic virus, whereas none of the wild species did exhibit any symptoms. Artificial inoculation provides a means to select desirable plant types having resistance to yellow vein mosaic disease.
  • ThesisItemOpen Access
    Pattern of root activity in bananas under irrigated and rainfed conditions
    (Department of Pomology and Floriculture, College of Horticulture, Vellanikkara, 1985) Sobhana, A; KAU; Aravindakhan, M
    The experiments were undertaken with an objective to find out the most active root zone of banana var. ‘Nendran’ employing radioactive 32p. These were conducted in the College of Horticulture, Kerala Agricultural University, Vellanikkara, during the year 1983-84. The field experiments were laid out in randomised block design, with three replications and the plants were raised under normal conditions. While taking into consideration the number, length and diameter fresh and dry weights of roots, all these were found to be more for the rainfed crop than the irrigated. This explains the enhanced production of roots under conditions of moisture stress. The radioactivity was injected at four months ago of the plant. The area around each experimental plant was injected with 32p solution with the help of a dispensette. The different lateral distances used for the 32p injection were 20cm, 40cm, 80cm and 120 cm and the different depths were 5cm, 15 cm , 30cm and 60cm. The third leaf was radio assayed and the 32p counts were used for finding out the percentage of active roots at the various treatment sites. The results of radiotracer studies indicated that maximum percentage of active roots was located at a soil zone covering 20cm distance and 30 cm depth from the base of the plant under irrigated condition, at five and six months age of the plant. The rainfed crop had its maximum percentage of active roots at a soil zone of 30cm deep and 40cm away from the plant. As the lateral distances increased from 20cm to 120cm, a reduction was noticed in the percentage activity of roots accordingly, under both irrigated and unirrigated conditions. But the root activity was not significantly different at different depths for the irrigated crop, which was significant for the rainfed crop. Under high moisture stress roots tend to forage into deeper layers of soil for getting the available water. Hence deeper soil zones had more active roots under unirrigated conditions, compared to irrigated crop, which had more surface active roots. An experiment was also organized to study of the translocation of absorbed 32p to various parts of the plant after flowering under irrigated condition. It was observed that male flowers had maximum concentration of 32p followed by female flowers or fruits. Of the various leaves, topmost younger leaves were found to build up more 32p than matured leaves, indicating a translocation to the developing immature leaves.
  • ThesisItemOpen Access
    Standardisation of methods of Vegetative Propagation in Mango
    (Department of Horticulture, College of Horticulture,Vellanikkara, 1984) Dhungana, D B; KAU; Aravindakshan, M
    The studies on the vegetative propagation of mango were carried out at the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara during the period from May 1982 to June 1984. The studies consisted of two techniques of grafting, viz. stone grafting and veneer grafting. It was possible to standardize these techniques under Kerala conditions for the first time after the detail studies of the factors like season of grafting, effect of procuring of scions, effect of age of stock and scion, varietal response, effect of duration of storage of scion sticks and methods of raising rootstocks. The results indicated that the survival of the stone grafts was best when the grafting was done during August. In case of veneer grafting, no significant difference in the survival of graft was observed during August, September and October although September was most congeneal month for grafting. Both the techniques of grafting revealed, the superiority of 10 days and 15 days prior defoliation of scions over no defoliation treatment. But the difference in the survival of grafts between the treatments with the defoliation 10 days and 15 days prior to grafting was not significant. In another experiment, the best result was achieved when four month scion was stone grafted on five days old stock material. However, the use of five days and 10 days old stock did not reveal any significant difference in the ultimate survival of the grafts. Similarly, the comparison of different age of stock and scions with regard to their effects on survival of veneer grafts proved, grafting with six month old scion using rootstocks 14 months old would give best results. On examining the extension growth of scion its linear nature was confirmed. The linear growth rate was found to be different for different treatment s in the present study. The scion varieties responded differently in the final success in veneer grafting. The promising effect on the graft take was noticed when the varieties, viz. Mundappa, Alphonso,Bangalora and Bennet Alphonso were adopted for veneer grafting. In varieties like Neelum and Banganapalli veneer grafting, did not appear to be satisfactory in mango under Kerala conditions. Any kind of scion stick i.e. prior defoliated or freshly defoliated when stored for a period of nine days at room temperature, did not prove significant difference in the survival of veneer grafts. However, gunny bag moss medium as wrapping material for scion shoots was found better than polythene moss medium. The modified trench method of grafting substantially improved the survival rate of polybagged veneer grafts
  • ThesisItemOpen Access
    Phenotypic stability analysis in bacterial wilt resistant lines of brinjal (Solanum melongena L.)
    (Department of Olericulture, College of Horticulture, Vellanikkara, 1987) Ushamani P, P; KAU; Peter, K V
    Twenty six genotypes of brinjal (Solanum melongena L.) were grown continuously in two seasons each under two contrasting environments in a randomised block design. Observations were recorded on yield and seven of its component characters. Significant variations among the genotypes were observed. G x E interaction was significant for plant height, primary branches/plant, percentage of productive flowers, fruits/plant, average fruit weight and yield/plant. The 26 lines were classified as suited to low, medium and high yielding environments. SM 6-6 M, SM 6-4 PL and SM 6-2 SP were suited to average environments; SM 6-6 PL and SM 6-3 SP suited to high yielding environments and SM 6-8PL and SM 6-1 SP suited to low yielding environments. The path analysis revealed fruits/plant and primary branches/plant having maximum direct effect on yield. The 26 lines were grouped into 4 clusters in each environment based on Mahalanobis D2 statistics. The intra and inter cluster distances and genotypes within clusters differed in the four trials. The stable lines were moderately resistant to bacterial wilt. They had root galls caused by Meloidogyne incognita. Root volume was positively correlated with yield. Survey conducted on preference to color and shape showed that white long and purple long fruits were the most preferred. The stable brinjal lines possessed this economic value also.