Time filter

Source Type

Bajpai A.,ICAR Central Institute for Subtropical Horticulture | Muthukumar M.,ICAR Central Institute for Subtropical Horticulture | Singh A.,Indian Agricultural Research Institute | Nath V.,National Research Center for Litchi | Ravishankar H.,ICAR IIHR
Indian Journal of Agricultural Sciences | Year: 2016

Litchi (Litchi chinensis Sonn.) is an introduced crop in India and has limited genetic variability characterized by differences in flushing pattern, leaf, panicle and fruit traits. Molecular markers were employed to expose the genetic diversity of 20 litchi cultivars from the Indian peninsula and facilitate documentation of the native germplasm diversity. Efficiency of individual primers was evaluated on the basis of average band informativeness and resolving power, where random oligonucleotide markers OPA-5 and OPA-3 scored best. Among tested microsatellite markers, ISSR 01 and 13 had high values for primer efficiency and these were found to supplement simple sequence repeats for generation of cultivar barcode and clustering analyses. Efficiency of microsatellites (Simple Sequence Repeats and Inter Simple Sequence Repeats) was established by high values for polymorphism (0.691), diversity index (0.264), effective multiplex ratio (48.8470) and marker index (12.896), thus reiterating its potential as for developing barcodes for cultivar identification and conservation. Phylogenetic analysis based on RAPD and microsatellites revealed clustering of the cultivars into four major groups, although within a very narrow range (0.63-0.90) of similarity, viz. Seedless (i.e. Bedana), Mandarji, Shahi and China groups. The clustering followed grouping based on fruit morphology, leaf and panicle attributes disagreeing with earlier views regarding incongruity of clustering pattern with morphological, ecological and climatic adaptations. Discrimination of cultivars like Dehrarose and Dehradun, being often labeled as synonyms, was also done. Interestingly high polymorphism and low gene diversity have been exposed by molecular markers, commenting on narrow genetic background of litchi cultivars from India.

The evaluation study on substrate dynamics under integrated plant nutrient management carried out for three years (2004-05 to 2006-07) at farmers field by National Research Centre for Litchi, Muzaffarpur, Bihar comprising of biofertilizers (Azospirillum, Azotobactor, Aspergillus, Trichoderma and Pseudomonas) conjointly with chemical fertilizers and organic manures on canopy spread, bearing behavior, yield and quality as well as soil chemical properties and cv. Shahi an important commercial and early variety of 14 years old in 2003 was used for the study. The three years cumulative results revealed that the treatment having Azotobactor (250 g tree-1) with half of the recommended dose of chemical fertilizer and 50 kg of FYM proved to be the most dynamic substrate to record maximum fruit yield (96.66 kg tree-1) categorizing maximum percentage of quality fruits under superior grade i.e. extra class (42.75%). This treatment also recorded better canopy spread, fruit weight and bearing (fruits/panicle) of heavier fruits though found at par with control i.e. the treatment having only chemical fertilizer which recorded fruit yield of 94.50 kg tree-1 categorizing less percentage of quality fruits under superior grade i.e. extra class (32.10%) suggesting a possibility for reducing N, P and K fertilizer dose to the tune of 50% and making quality litchi production economically more viable. Physicochemical characteristics as recorded in different treatments showed higher values in substrate having biofertilizer in particular. The effect of treatments on available N, P and K status of the soil was found profoundly influenced at the end of experimentation and was appreciably higher particularly in case of treatments having biofertilizers when compared to the initial status.

Kumar R.,National Research Center for Litchi
Acta Horticulturae | Year: 2014

Litchi has attained the status of an important commercial fruit crop of India. The factors leading to its successful cultivation, high productivity and fruit quality are generally environmental parameters like temperature, photoperiod/light intensity, soil moisture content and humidity in the atmosphere. The findings of research studies conducted at NRC for Litchi in Muzaffarpur, Bihar, India, during the last decade (2001-2010) prove that changing climate is influencing the trend of litchi production system as well as areas under litchi plantations. On comparing litchi production in a particular region with the ideal climatic conditions for commercial viability, it has been found that higher temperature, good sunshine and adequate soil moisture in the rhizosphere result in improved fruit size and quality. The aberrations in weather like prolonged cloudy weather and rains during the full bloom hamper normal cross pollination and fruit set in litchi. In addition, moist weather leads to severe attacks of mite and other insects as well as incidence of lichen growth on the trunk and branches causing bark splitting, leading to other fungus infestation in the litchi crop. Preharvest low intensity sunshine due to cloudy weather reduces the content of ascorbic acid and sugar in the fruit. The studies prove that influence of climatic aberrations can be nullified to a great extent by practicing region specific adaptation measures like soil moisture conservation, pruning and canopy management, mulching, growing intercrops, water and nutrient management and pest management resulting in enhanced productivity and quality.

Pollination is a vital step in a litchi production system, as both fruit yield and quality are dependent on the extent of cross pollination. The extent of crosspollination and enhanced fruit setting in litchi is significantly carried out by honey bees in the region. The present study made on pollination recommendations and practices in litchi during the two-year period of 2009-10 and 2010-11 at NRC for litchi, Muzaffarpur, Bihar, which envisaged placing honey bees in litchi orchards, gives an important and practical solution for assuring adequate pollination and fruit set. The foraging studies, more particularly in litchi flowering season, have given an indication that a minimum range of 5 to 10 honey bee colonies per ha of litchi cultivation should be provided. This study is based on the tentative number of visits of honey bees per panicle in litchi orchards having 144 litchi plants/ha at a spacing of 8.0 m. The extent of pollination and fruit set exclusively by honey bees has been recorded under controlled pollination experiments. The assessment of fruit yield and quality attributes have shown quite encouraging results confirming the significant role of honeybees in planned bee pollination. The response of cross- versus selfpollination through controlled pollination has been found distinct in litchi ('Shahi') fruit production. No fruit set in the case of controlled pollination under cages indicated sterile flowers in the same tree. The present study clearly spelled the need for an abundance of insect pollinators in a planned way for pollen transfer to complete the process of cross pollination and fruit set to achieve potential yield and quality. The European honey bee (Apis mellifera) has been found the most efficient pollinator of litchi as compared to others.

Kumar R.,National Research Center for Litchi
Indian Journal of Agricultural Sciences | Year: 2014

A field experiment was carried out by National Research Centre on Litchi, Muzaffarpur, Bihar at farmers field for two years during 2008-09 and 2009-10 in an orchard having 18 years old litchi (Litchi chinensis Sonn.) plantation of cv Shahi spaced at 10 m × 10 m have shown the significant need of pruning operation and proper nutrition in commercial bearing litchi trees, which must maintain control of both tree size and fruit productivity. The types of pruning, i.e. Selective pruning to frame semicircular canopy shape and pruning to centre open the canopy with nutrition including recommended dose of fertilizers (RDF) application have been found to give significant effect on plant height, canopy volume (m3), shoot length, shoots with bearing panicle, initial fruit set (no./panicle) and fruit yield as well as fruit weight at both treatment level and their interaction effect. Among the various treatments, selective pruning (65.65 kg/plant; 86.35 kg/plant) and nutrient application in recommended dose (60.48 kg/plant; 67.35 kg/plant) resulted in highest fruit production during both the years and their interaction effect was also found to be significant. In both the years, fruit yield increased with types of pruning system and nutrition. During the end of the experimentation, the initial and after soil test analysis for physicochemical properties showed the appreciable increase in the soil organic matter and the NPK availability status improving the soil physical properties.

Discover hidden collaborations