Management of Pre and Post Harvest Fruit rot diseases of Ber

Introduction

Ber (Ziziphus mauritiana Lam.) is a drought-hardy plant and called as poor man’s apple it ‘is highly suited to arid conditions. Ber cultivation is not only increases the income of poor farmers in arid regions but also enriches the nutritional status of people. Ber is cultivated all over the drier parts of the Indian subcontinent for its fresh fruits, which are rich in vitamins (C, A and B-complex) and minerals. In the current ber production areas, work is mainly required for protection against fruit rot, fruit fly, and fruit borer. Alternaria and Colletotrichum fruit rot are the major diseases in ber (Zizyphus mauritiana  Lam.) which causes post-harvest loss upto 30 per cent. There are two different types of fruit rot that occur in ber in one type of  fruit rot is observed in immature fruits / pea-shaped fruits in natural conditions caused by Colletotrichum. Such fruit rot incidence was more in field conditions with a per cent incidence of more than 50 per cent. The affected immature or pea shaped fruits become fully purple coloured which appears during the month of August-September and shed off before maturation. Another type of fruit rot caused by Alternaria occurs at the marble stage of fruit in which the rotting partially starts from the pedicel of the fruit and further it extends  to cover the entire fruit  and cause economic loss to the crop. The ber fruits after harvest are infected very much by post-harvest fungal pathogens such as Botryodiplodia, Colletotrichum, Alternaria and Rhizopus. Hence the study was undertaken to manage the fruit rots in ber both in field conditions and after harvest effectively.

Materials and Methods

The experimental trial was conducted from 2015 to 2018 to study the efficacy of pre–harvest spraying of fungicides in field conditions for the control of fruit rot in ber caused by Colletotrichum and Alternaria. The experiment was conducted at the Regional Research Station, Tamil Nadu Agricultural University, Aruppukottai in a randomized block design. There were eight treatments and three replications. Two sprays were given one at pea stage and another at marble stage of ber fruits and the spray starts after occurrence of the fruit rot incidence. The per cent disease incidence was calculated and the experimental results are furnished below in table 1.

The efficacy of post-harvest treatment of chemicals on fungal rot incidence was assessed in ber fruits. The harvested fruits were dipped for 10 minutes in different chemicals viz., Potassium metabisulphite (3%), Borax (3%), Sodium chloride (2%), Carbendazim (0.1%), Paushamycin (0.05%) and compared with untreated control. The fruits were frequently examined for the development of rotting and the results of the experiment are presented in table 2.

Results and Discussion

The results of pre-harvest spraying of fungicides for the management of fruit rot in ber are furnished in table 1. The results revealed that two pre-harvest sprays of 0.1 per cent Thiophanate Methyl at 15 day intervals during the marble stage of ber fruit was found effective against Alternaria fruit rot which recorded 6.8 PDI followed by 0.25 percent copper oxychloride (7.1 PDI) compared to untreated control which recorded 43.6 PDI. In pea fruit stage of ber, two pre harvest sprays of 0.1 per cent carbendazim was found effective against Colletotrichum fruit rot which recorded 6.6 PDI followed by 0.25 per cent copper oxy chloride (11.1 PDI) which was on par with Thiophanate methyl (0.1%) (11.8 PDI) compared to untreated control which recorded 44.2 PDI.

The results of post-harvest treatment of chemicals and fungicides for the management of fruit rot in ber are furnished in Table 2. The results revealed that dipping of ber fruits in 2 per cent sodium chloride solution for 10 min. recorded the lowest PDI of 5.27 against post-harvest fungal rot as compared to untreated control recorded 25.27 PDI. The microorganisms responsible for post-harvest rot in ber were Botryodiplodia, Colletotrichum, Alternaria, and Rhizopus. The results were supported by the findings of Misra et al. (2013), Maheswari and Haldhar (2018) and Nallathambi et al. (2000) and (2009).

            The research is further strengthened by including SEM studies to magnfy the fruits after post harvest treatment and residual analysis if needed.

Acknowledgement:

             The author acknowledge the ICAR-Central Institute of Arid Horticulture, Bikaner and Tamil Nadu Agricultural University for their tremendous support and funding in this research.

References:

1. Misra, D.K., 1 J. Saha, 1P.V. Devidas and F.K. Bauri. 2013. Diseases of ber (Zizyphus jujube) in Eastern India. The Journal of Plant Protection Sciences, 5(1): 65-69.
2. Maheshwari, S. K. and S. M. Haldhar. 2018. Disease Management in Arid Horticultural Crops. Technical Bulletin No. 68. CIAH/Tech./Pub. No. 68, ICAR-Central Institute for Arid Horticulture, Bikaner, Rajasthan, India, P. 42.
3. Nallathambi P, Umamaheswari C, Vashishtha BB, Vishal Nath (2000) Fruit rot (Alternaria alternata) and sources of resistance in ber germplasm under arid conditions. Annals of Arid Zone 39:477–478
4. Nallathambi P, Umamaheswari C, Thakore BBL, More TA (2009) Postharvest management of ber (Ziziphus mauritiana Lamk.) fruit rot (Alternaria alternata Fr. Keissler) using Trichoderma species, fungicides and their combinations. Crop Prot 28:525–532