The total collection in mango stands at 538. Evaluation of germplasm showed that the variety Sora had the maximum fruit weight (1166 g) followed by the variety Tenneru (945 g). It was found to be minimum in Kalakai (88 g). Screening of the 32 mango varieties for fruit fly showed that the varieties Bhuto Bombay and Virudhunagar when exposed to fruit fly under artificial conditions did not record any infestation. The varieties Gopal Bhog, Bhutto Bombay, Manipur, Manibhatta Appe and Virudhunagar did not show any stone weevil infestation.
The total collection in guava stands at 76 including five species.
Germplasm of 33 Sapota accessions are being maintained in the field. An open pollinated seedling progeny of Cricket Ball (no.63) isolated has been multiplied by grafted and 20 grafts are planted in field for further evaluation.
Nine accessions of Jamun were collected from various sources like KRCC, Arabhavi (6 accessions), CISH, Lucknow (2 accessions) and one Konkan Bahadoli from Regional Fruit Research Station, Vengurle.
At present, 42 accessions of underutilized fruits are being maintained. A total of 19 accessions in jackfruit and 9 in pummelo have been evaluated. The accession G-65 continued to be superior in jackfruit. In pummelo, a pink pulped accession has also been found good with respect to quality.
At present 32 accessions including two species are being maintained. The evaluation of the intergeneric hybrid progenies for PRSV, a few progenies are showing tolerance in addition to good fruit quality.
As pollen germination under stress is one of the indirect ways of assessing drought tolerance, different accessions of Carica papaya were evaluated by artificial pollen germination. Amongst the 32 accessions tried, V. cauliflora, Dwarf Lilly and CO6 recorded pollen germination over 50 per cent.
Two accessions of pomegranate have been introduced from Afghanistan one with acidic taste and the other with sweet and seedlings raised from them. Screening of nearly 500 progenies of Daru, Nana (Yellow) and Nana (Red) was taken up and found that Daru had highest per cent (51.41) of population resistant to BBP. Nearly 5000 seedlings of Daru, Nana and OPs of Bhagwa were raised for evaluation against BBP. Two hybrids of DF x N with less spines were identified as a source of breeding lines.
Sixty six accessions were added. Three hundred forty four putative disease tolerant hybrids with various degree of tolerance to different fungal diseases (based on one season of screening/field survival) are being furthered for rigorous screening.
A total of twelve genotypes are being maintained.
Canopy architecture (Mango, grapes and fig)
In the field trial involving planting densities of 1111 (3m x 3m), 400 (5m x 5m) and 178 (7.5m x 7.5m) ‘Alphonso’ trees / ha. on ‘Vellaikulumban’ and ‘Olour’ rootstocks with or without the application of paclobutrazol, the vegetative growth parameters were lower for paclobutrazol applied trees and those on Vellaikulamban rootstock. Flowering was more at wider spacing and on trees that received paclobutrazol treatments, the trend being more pronounced with Olour rootstock. The highest fruit yield of 14.63 t / ha during the twelfth orchard year was obtained with 3m X 3m spacing using Olour rootstock and 1.25 g paclobutrazol / tree compared control at 10m X 10m spacing (100 trees / ha) on random Totapuri rootstock without paclobutrazol yielding only 4.64 t/ha. The treatment combinations did not significantly affect fruit quality, though acidity tended to be more for closer spacing. Paclobutrazol residues in surface soil (0-15 cm) samples collected from under mango tree canopy at the time of fruit harvest were in the range of 0.044 to 1.145 mg / kg for the lower application rate (0.125 g / tree / year of age) and in the range of 0.096 – 1.88 mg / kg for the higher application rate (0.25 g / tree / year of age), but fruit samples from all the treatment combinations were free of any paclobutrazol residues.