Search

Cocoa is an important plantation crop grown in southern parts of India. Though many cocoa varieties have been released for cultivation in different parts of India, there is no variety recommended for cultivation exclusively for India’s North East region, especially Assam, where arecanut is grown as an important cash crop. Therefore the present investigation was undertaken to study the performance of twelve cocoa genotypes for its growth, pod yield and yield attributing traits for subsequent research programmes. The data for growth, pod yield and yield attributing traits were recorded three years after planting for five years (2015 to 2019), and the mean data were used for analysis. Genotype VTLC 11 significantly produced greater plant height (2.70 m), stem circumference (27.73 cm), height at jorquetting (36.16 cm) and canopy area (17.00 m2). Mean average pod yield among the genotypes varied from 20.65 to 48.40 tree-1 year-1. Genotype VTLC 19 produced significantly higher pod yield (48.40), number of fresh beans pod-1 (34.06), fresh bean weight pod-1 (229.65 g), dry bean weight pod-1 (119.32 g), single dry bean weight (1.20 g) and dry bean yield (1.76 kg). Considering the most economic traits of cocoa, VTLC 19 appears to be the most suitable genotype for commercial cultivation in the region.

High density planting system i.e. accommodating a higher number of plants than routine in a given area is an innovative agro-technology to increase yield and thereby early net returns. Due to conventional wide spacing plantation in Nagpur mandarin (Citrus reticulata Blanco), the land remains unutilized as the plant canopy gradually increases over the years. In the present study, Nagpur mandarin (Citrus reticulata Blanco) budded on Rangpur lime rootstock was evaluated under six different planting spacings. It was observed that the organic carbon (1.10–1.82%) and major nutrients viz. N (309–430 kg ha−1), P (20–54 kg ha−1) and K (291–810 kg ha−1) increased vis-à-vis plant density and was highest under 2 × 2 m spacing. Plants were tallest at 2 × 2 m spacing with the higher PAR interception (88.2) and the lowest leaf area index (1.09). Fruit yield on area basis, under 2 × 2 m spacing was 26, 7.1, 4.6 times more as compared to conventional plantation during the first, second and third year, respectively. At fifth year of crop harvest, the highest B:C ratio (6.36) was recorded in 6 × 3 m followed by 4 × 2 m and 2 × 2 m.

Knowledge, skill and attitudes are the most important factors affecting socio personal attributes of human resources. ICAR-Central Plantation Crops Research Institute, Research Centre, Kahikuchi, organizes training to develop more skilled workforce. Training of two batches of 50 farmers each on cocoa cultivation and processing technology was conducted for three consecutive days both during 2016 and 2017. The study was done mainly to create awareness and disseminate the new technologies on cocoa and to study their feedback concerning cocoa cultivation and processing technique. Socio personal attributes of the farmers, pre and post evaluation and perception of the trainees are studied to understand the level of change in their knowledge and skill after undergoing training. Majority of the respondent was found to possess positive impact in the development of knowledge and skill on scientific method of cocoa cultivation and processing technique. The study also showed that education qualification and mass media exposure were found to help enhance knowledge and skill of the trainees.

Ricebean (Vigna umbellata (Thunb.) Ohwi and Ohashi), believed to be domesticated in Myanmar–Thailand region, is grown in the North-Eastern hills of India as a pulse, vegetable, and fodder crop. Depending on the farming system where it is grown, plant types vary. Sixty-five accessions collected from across the North-Eastern hills of India were characterized for ten quantitative and ten qualitative morpho-agronomic traits using a minimal descriptor. Different data transformation and dissimilarity calculation methods were used to assess diversity. Mean dissimilarity using the average taxonomic distance was 14.05 (0.141) and using Gower’s general coefficient was 0.249. Both methods identified four clusters where one of the clusters contained more than 70% of the accessions. One of the accessions, BKSB-40, was identified as a unique accession. Quantitative traits were further grouped into qualitative factors, which gave an idea of farmer's preference for plant type and indicated wide difference between accessions collected from areas bordering Myanmar and East Nepal.

High density planting system is exploited to increase yield and thereby net return by accommodating higher number of plants in a given area. It is beneficial especially in fruit crops like acid lime where the plant canopy gradually increases over the years and until then land remains unutilized due to conventional wide spacing plantation. In the present study the seedlings of acid lime cv. Pramalini plantation was evaluated under ultra-high density planting (UHD - 1600 trees ha−1 at 2.5 × 2.5 m) and high density planting (HDP - 800 trees ha−1 at 5 × 2.5 m) systems over conventional or control (CON - 400 trees ha−1 at 5 × 5 m) planting spacing. The climate of the study area was tropical, dry, sub-humid having yearly average maximum and minimum temperature 34.2 °C to 20.5 and precipitation of 1128 mm. Field soil having montmorillonitic mineralogy was 40 cm deep. Data on plant growth, soil properties, insect pest (leaf miner), disease (bacterial canker), physico-chemical parameters of fruits and fruit yield were recorded three years after planting of seedlings in the experimental field. It was found that under both UHD and HDP, EC gradually decreased over the period of five years. The highest organic carbon (1.13–1.42 %) and major nutrients were observed under UHD and leaf N and K contents in HDP. Dense and vigorous plant canopy with maximum (1.49) leaf area index was found in HDP and lowest was under UHD (1.18). Although insect – pest and disease incidence was higher in close spacing plantation than CON, physico-chemical fruit parameters were not affected by spacing. The fruit yield on per plant basis was always significantly lowest under UHD. However, on area basis, under UHD plantation fruit yield (8.24–35.36 t ha−1) was more than two folds as compared to control (3.08–11.64 t ha−1) for different years. Although during last year of experiment the yield under ultra-high density planting (35.36 t ha−1) was significantly higher than high density planting (25.09 t ha−1), the B:C ratio was nearly similar in both the cases. Therefore, it may concluded that the high density planting system may be preferred during early years of production.

Rice bean [Vigna umbellate (Thumb.) Ohwi and Ohashi] is an underutilized crop believed to be domesticated in the Myanmar-Thailand region of Asia. In India, rice bean is mainly cultivated in the North-Eastern Hills, which is a hotspot for biological diversity. A 5' anchored PCR was used to develop microsatellite markers in rice bean. Twenty-eight specific primer pairs were designed and employed to characterize sixty five ricebean accessions collected from North East India. A total of 179 alleles were amplified with an average of 6.393 alleles per locus. The gene diversity was high (mean 0.534) in the accessions collected from Darjeeling, Nagaland and Manipur, which are bordering areas with East Nepal and Myanmar, respectively. Exceptionally high outcrossing rate was observed in the entire population. Population structure analysis identified three distinct clusters in which accessions collected from areas bordering Myanmar and East Nepal grouped separately. Using a combination of STRUCTURE and Principal Coordinate Analysis, relative affinity of the intermediate accessions could be established. However, differences in allelic counts among populations were non-significant. The results showed that there is a high level of genetic diversity within the accessions, with high outcrossing rate.

The safflower (Carthamus tinctorius L.) is considered a strongly domesticated species with a long history of cultivation. The hybridization of safflower with its wild relatives has played an important role in the evolution of cultivars and is of particular interest with regards to their production of high quality edible oils. Original safflower varieties were all rich in linoleic acid, while varieties rich in oleic acid have risen to prominence in recent decades. The high oleic acid trait is controlled by a partially recessive allele ol at a single locus OL. The ol allele was found to be a defective microsomal oleate desaturase FAD2-1. Here we present DNA sequence data and DNA Southern blot analysis suggesting that there has been an ancient hybridization and introgression of the FAD2-1 gene into C. tinctorius from its wild relative C. palaestinus. It is from this gene that FAD2-1Δ was derived more recently. Identification and characterization of the genetic origin and diversity of FAD2-1 could aid safflower breeders in reducing population size and generations required for the development of new high oleic acid varieties by using perfect molecular marker-assisted selection.

From the results of Barry degradation studies, the 1→3 and 1→4 linked glucopyranose units present in the glucan have been proved to occur in blocks. Size and shape of the glucan have been determined from light-scattering measurements.