Occurrence and distribution of black pod rot of Cocoa (Theobromae cocoa L.) in southern transition zone of Karnataka

Straminipile genus Phytophthora cause significant disease losses to global cocoa production. Phytopthtora palmivora is one of the major constraints in cocoa production causes significant pod losses. P. palmivora has a complex disease cycle involving several sources of primary inoculum and several modes of dissemination of secondary inoculum. This results in explosive epidemics during favorable environmental conditions. Highest severity of Seedling blight was observed in raised bed nurseries as compared to poly bag nurseries in Shivamogga district (59.26%) followed by Chikkamagluru (53.85%) of the state Karnataka , respectively. Further, the highest incidence of 72.00, 70.83 and 70.00% of black pod rot disease was recorded in Udupi, Dakshina Kannada and Shivamogga district followed by Chikkamagaluru (65.22%), Kodagu (64.00%) and Davanagere (55.56%) district respectively. Due to continuous rain fall or high moisture conditions and the crop was grown as intercrop with arecanut is vulnerable for the attack of pathogen due to the presence of pathogenic variability

Studies on genetic variability and relationship of bael (Aegle marmelos (L) Correa) using morphological and molecular markers

Bael (Aegle marmelos (L) Correa) is an important underutilized fruit crop of India. A total of 25 bael trees were selected from 356 bael trees of Sakharayapattana in Chikkamagalur district, Karnataka, India based on the fruit morphological traits (fruit weight, pulp weight, skull thickness, seed weight per fruit, No. of seeds per fruit, No. of locules per fruit, No. of seeds per locule, pulp wt. : seed wt.). These 25 trees were evaluated for phenotypic and genotypic variations using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) markers. RAPD and ISSR markers showed significant polymorphism among the trees. Jaccard’s genetic similarity value of RAPD and ISSR was found in the range of 0.00–0.95 and 0.06–0.56, respectively suggesting a moderate level of genetic diversity. The present study revealed that molecular markers can be successfully utilized for determining genetic diversity and relationship of bael trees for further varietal improvement

Characterization and evaluation of morphological and yield traits of tamarind genotypes

The evaluation of morphological and yield traits of tamarind genotypes was carried out during 2017-18 at Forest Research Station, Govinkovi, Honnali taluk, Davangere district. The experiment was laid out in randomized complete block design with 16 genotypes and three replications. Trees were 14-years-old and of grafted origin. All the morphological and yield traits showed significant difference among the selected genotypes indicating the presence of adequate variations. The genotypes recorded morphological variation in terms of tree shape (semi-circle to irregular shape), foliage arrangement (dense to sparse), flowering time (early, mid and late), stem colour (dark brown, brown and light brown), bud colour (greenish white, pink, dark pink), petal colour (yellow and pale yellow), pod colour (greyish brown, brown, light brown and dark brown), pulp colour (light brown, brown and reddish brown), pod shape (straight, slightly curved, curved and deeply curved) and pod size (very big, big, medium and small). The analysis of variance revealed significant difference with respect to tree height, stem girth, pod traits, pod yield per tree (K-9 : 12.80 kg), number of pods per tree (NTI-52 : 989.07) and pulp per cent (K-9 : 48.87). Among the 16 genotypes, the genotype K-9 was found superior with respect to pod size, pod weight, pulp weight and pod yield per tree. Genotype K-9 was found promising and due to perennial in nature further evaluation is required for stability

Effect of foliar application of micronutrients on ginger productivity: Foliar application of micronutrient on ginger productivity

Ginger (Zingiber officinale Rosc) is cultivated in different agro-climatic zones of Karnataka. Correction of deficiency of nutrients through foliar application of micronutrients is imperative to maintain the growth and development of the crop. Hence, large scale demonstrations were conducted and the impact analysis of crop specific ICAR-Indian Institute of Spices Research, Kozhikode-micronutrient formulation (released as “Ginger Special”) on productivity and profitability of ginger in Southern Transitional Zone of Karnataka was carried out during 2016- 19 by involving 429 farmers in an area of 133.20 ha. Foliar application of ginger special (5 gl-1), 45 days after planting up to six months at an interval of 45 days showed significant increase in fresh yield (23.94 t ha-1), higher returns ha-1 (Rs.9,80,300) and higher BCR (2.89). The test farmers who used ginger special obtained a mean additional fresh yield (2.44 t ha-1), additional return (Rs. 99,500 ha-1) besides providing additional employment to the farm workers (12 ha-1). Use of ginger special, created a good impact on productivity and profitability of ginger cultivation and the technology has spread in an area of 500 ha in Shivamogga district of Karnataka

Phenotypic Plasticity in Morphological Traits of Abelmoschus esculentus L. Induced by Histone Deacetylase Inhibitor, Trichostatin A

Epigenetic changes such as DNA methylation and histone modifications, when meiotically inherited across generations, can act as a stable evolutionary force that is independent of any accompanying DNA mutations. Certain histone deacetylase (HDAC)-inhibiting chemicals such as Trichostatin A (TSA) and sodium butyrate are known to regulate the total acetylated histones in the genome, which is important for regulating the expression of various traits in all organisms. This study investigated all morphological variations in traits of Abelmoschus esculentus L. (okra) induced by different doses of Trichostatin A in a popular okra variety, Arka Abhay. Two sets of seeds were treated with two doses (0.4 µM and 1.2 µM) of TSA and were incubated in the chemical for three and five days, respectively, to record the effects of dose and incubation periods on various agronomic characters of okra. The treatment of TSA had a negative impact on the majority of the characters under evaluation. Total seedlings emerged, and mean shoot and root length were retarded following the TSA treatment. Extremely dwarfed plants with malformed leaves and flowers were a common observation. Pollen sterility combined with distortion of the reproductive whorls of the flowers were particularly pronounced at high doses with a prolonged incubation period. Treated plants had a significantly delayed first flowering and produced short fruits with altered morphology. Variations in seeds with respect to the number, colour and size were also recorded. Total reduction with respect to seedling parameters, total pollen production, the number of fertile pollens, plant height and other damaging effects on leaves, flowers, fruits and seeds increased as the dose and incubation period increased. Statistical analysis revealed the significant negative effect of TSA treatments on plant height, the number of ridges and locules per fruit, number of seeds per fruit and test weight. The treatment, 1.2 µM Trichostatin A incubated for three days, showed a remarkable difference as traits such as total field emergence, seedling parameters and days to first flowering plant height, number of seeds per fruit and test weight deviated from the expected trend of decreasing growth parameters as the dose and incubation period increased. The study further revealed that the treatment (1.2 µM TSA incubated for three days) can be suggested for use in okra to induce epigenetic variations without significantly compromising the growth and vigour parameters of okra

Action Plan for the year 2011-12 to 2022-23 of ICAR-Krishi Vigyan Kendra, Shivamogga

Not AvailableNot AvailableNot Availabl