Evaluation of tomato hybrid Arka Abhed against multiple disease resistance in Nizamabad District

Introduction

Tomato (Lycopersicon esculentum Mill.) is one of the most important vegetable crops grown almost throughout the world including tropical and temperate regions. It is cultivated both in the green houses under protective structures as well as under natural conditions. It is consumed fresh as salad, used in culinary preparations and processed in to various forms viz. Ketchup sauces, puree, paste, powder, juice, soup, chutney etc. It is inseparable with fast foods such as pizza, burger, noodles etc. will not taste the same without addition of tomato sauces. Tomato is a rich source of vitamins A and C and is referred to as "poor man's orange". Tomato is a very good appetizer and its soup is said to be a good remedy for patients suffering from constipation. Lycopene that imparts red colour to ripe tomatoes is reported to possess anticancerous properties. It also serve as a natural antioxidant as the Beta-carotene functions to help prevent and neutralize free radical chain reaction and ascorbic acid is an effective scavenger of superoxide, hydrogen peroxide, singlet oxygen and other free radicals (Dhaliwal, 2014) [2] . Tomato cultivation in India is consistently challenged by pervasive biotic stresses, leading to substantial yield losses and necessitating intensive chemical management. Insect pests like Tuta absoluta, fungal diseases such as Early Blight and Late Blight, and viral diseases, most notably Tomato Leaf Curl Virus Disease (ToLCVD), caused by whiteflytransmitted begomoviruses. Early and late blight diseases causing an incidence of 49-91% in conducive conditions (Azam and Shah, 2003) [1] . Traditional commercial hybrids cultivated by farmers often display high susceptibility, leading to elevated production costs due to prophylactic and curative chemical spray regimes. According to an estimate, there could be yield losses to an upward of 85-90% (Ravuri and Kumar, 2018) [8] due early and late blight diseases with farmers relying upon repeated fungicidal sprays to control the disease. Fungicides have such adverse effects as environment pollution, and they are not able to control blights under some conditions that favour heavy disease pressure (Ko, 1994) [4] . Host resistance comes into limelight under these circumstances which reduces the disease incidence thereby reduces cost of cultivation to the farmers. Mukalazi et al., (2001) [6] reported that host resistance is an important element in late blight management due to its long-term economic benefits for small-scale farmers and decreasing the likelihood of the development of fungicide resistance. In the view of the above problem identified by the scientists of KVK, Nizamabad (Rudrur) assessed the performance of tomato hybrid Arka Abhed during Kharif Seasons of 2022 and www.extensionjournal.com 2023.

Materials and Methodology

Krishi Vigyan Kendra, Nizamabad (Rudrur) conducted On Farm Trial (OFT) on tomato hybrid 'Arka Abhed' during Kharif, 2021 and 2022 at 6 locations in KVK adopted village shankora and compared against private hybrid US-440. Arka Abhed (IIHR H-397) is a multiple disease resistance variety developed by the Indian Institute of Horticultural Research (IIHR) designed to address these combined threats by employing pyramided resistance genes, possessing resistance to ToLCV (utilizing Ty2+Ty3 genes), Bacterial Wilt, Early Blight, and Late Blight (utilizing Ph2+Ph3 genes). It is a semi-determinate hybrid yielding between 70 and 75 t/ha over a 140 to 150-day cycle, making it suitable for cultivation across the summer, Kharif, and Rabi seasons. Data on early blight incidence was collected from vegetative stage to fruiting stage in all the locations Observations were recorded on appearance of diseases, disease severity and fruit yield per plot. The data on disease severity was recorded before spray as initial, 10 days after the spray. The severity of early blight was recorded on 10 plants were selected at randomly in each replication of the treatment. Mean severity percent was calculated based on limits depending upon visual symptoms given in the following Table . Rating scale for assessment of early blight disease (Mayee and Datar, 1986) [5] Grade Description of the symptoms 0

No symptoms on the leaf 1 0-5 per cent leaf area infected and covered by spot on leaf 2 6-20 per cent leaf area infected and covered by spot, some spots on petiole 3 21-40 per cent leaf area infected and covered by spot, spots also seen on petiole, branches 4 41-70 per cent leaf area infected and covered by spot, spots also seen on petiole, braches, stem 5 >71 per cent leaf area infected and covered by spot, spots also seen on petiole, branch, stem, fruits Percent disease index (PDI) was calculated by using the formula given by Wheeler (1969). A technology index was prepared to test technical feasibility due to implementation of the trial in tomato. To estimate the technology gap, extension gap and technology index the following formula was used given by Samui et al., (2000) [11] , Sagar and Chandra (2004) [10] . During fruiting stage 40% of early blight incidence was observed in private hybrid, whereas in Arka Abhed 3.5% of early blight incidence was observed. This might be attributed to high disease pressure and favourable environmental conditions for spread of the disease.

Yield Performance and Stability in Biotic Stress Environments

The pooled mean yield of Arka Abhed (702.50 q/ha) showed a modest but statistically relevant 3.52% increase over the farmer's check (678.59 q/ha) (Table 3). However, a highlevel interpretation of the year-wise data reveals yield stability. [7,9] .

Demonstration of Disease Resistance and Economic Returns

The core strength of the Arka Abhed technology is its economic efficiency, directly stemming from its disease resistance. The 9.89% reduction in cost of cultivation for Arka Abhed is the most significant finding, validating the farmer feedback that the hybrid was "less prone to disease and pest incidence, saving him the cost towards chemical sprays." This reduction is a direct demonstration of the value of the ToLCV (Ty2+Ty3) and Early Blight resistance genes, minimizing the need for expensive and frequent plant protection measures.

Technological Adoption and Feasibility (Technological Aspects)

To assess the potential for widespread adoption, the technology was evaluated using the Technology Index (TI) (Murthy and Kameswari, 2024) [7] . The low Technology Index (6.33%) is a strong technological indicator and demonstrates that the improved technology performs close to its maximum potential under actual field conditions. This suggests minimal constraints during technology transfer, confirming Arka Abhed's high adaptability to the micro-farming situation and high potential for successful horizontal spread. The calculated Extension Gap of 23.91 q/ha further reinforces the need for extension efforts to motivate farmers to switch to this superior, stressresilient hybrid.

Acknowledgement

AcknowledgementThis study was financially supported by Krishi Vigyan Kendra, Nizamabad (Rudrur) and authors are grateful to www.extensionjournal.com PJTSAU, Rajendranagar and ICAR-ATARI, Zone -X, Hyderabad and for necessary support and guidance to complete this work successfully.

References

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