Fruit cultivation not only plays a crucial role in nutritional security but also offers employment opportunities, higher income and productivity to the farming community. Biotic and abiotic stresses are the most ominous factors in fruit production, which reduces the growth and productivity thereby resulting in an impact on global fruit production and availability. Biotic and abiotic stresses, including drought, extremes of temperature, various pest and diseases, salinity in soil and water are problems which are becoming acute. There is an urgent need to improve biotic and abiotic stress tolerance in fruit crops by using traditional breeding and biotechnology approaches like gene silencing and transgrafting. Nowadays, the virus resistance transgenic rootstocks are developed by using small interfering RNA s (silencing RNA) method. Rootstock breeding in fruit crops is a great challenge due to difficulty in identification of tolerant or resistance rootstock for various purposes. In this paper, we have discussed the various biotic and abiotic stresses, resistance mechanisms, and available resistant rootstocks so far as well as challenges in rootstock breeding which can be helpful to manage stress conditions in fruit cultivation. Further research is needed to develop the resistance rootstocks by using modern rootstock breeding methods with various biotechnological approaches.

Muscat Hamburg (Panneer) is the most popular cultivar in Tamil Nadu for its pleasant musk flavor. It is consumed as table variety and also used for juice and wine-making purposes. The present investigation was conducted during summer and winter pruning from April 2016 to March 2018, in the grapes vineyard located at Shanmuganathy dam road, Rayappanpatty village in Cumbum valley of Theni district, Tamil Nadu. The experiment was laid out by adopting Randomized Block Design with seven treatments and three replications. The exeprimental results revealed that the treatment with foliar application of chelated EDTA calcium @ 0.2% + boric acid @ 0.1% recorded the maximum number of bunches (41.00 vine-1), fruit yield (14.87 kg vine-1), individual bunch weight (636.87g), bunch volume (498.42 mL) and TSS (19.530brix). The minimum berry cracking (3.46%), titrable acidity (0.52%) and physiological loss in weight (10.18%) were also recorded in the treatment with chelated EDTA calcium @ 0.2% + boric acid @ 0.1% (T5) as compared to other treatments. Further, the same treatment combination noted the lowest berry shattering (2.42%). Whereas the highest berry diameter was recorded in the treatment with a spray of calcium chloride @ 0.3% than all other treatments.

An experiment was conducted to assess the effect of pre-harvest treatments on biometrical, physiochemical and shelf life in grapes variety Muscat Hamburg. The experiment was conducted in randomized block design with 14 treatments (T1 (Ca(NO3)2 0.5%), T2 (Ca(NO3)2 1.0%), T3 (KNO3 0.5%), T4 (KNO3 1.0%), T5 (CaCl2 0.5%), T6 (CaCl2 1.0%), T7 (sulphate of potash (SOP) 0.5%), T8 (SOP 1.0%), T9 (T1+T3), T10 (T2+T4), T11 (T5+T7), T12 (T6+T8), T13 (water spray) and T14 (control)) in two replications and imposed at berry development and veraison stage. The data revealed that T12 showed the highest values for bunch weight, fruit yield vine -1 , berry diameter, berry weight, seed weight, berry firmness, juice recovery, TSS, total sugars, reducing sugars, non-reducing sugars, shelf life, petiole potassium and berry potassium with the least berry cracking, berry shattering, PLW and berry rotting. While T14 showed the lowest values for yield and quality parameters. The treatment T11 recorded the highest anthocyanin and total phenols content. T10 expressed the maximum nitrogen content in petiole, whereas T8 recorded the highest petiole phosphorus. The petiole calcium was more in T6. The highest petiole magnesium was found in T3.