Vegetable and fruit plants facilitate around 7.5 billion people around the globe, playing a crucial role in sustaining life on the planet. The rapid increase in the use of chemicals such as fungicides and bactericides to curtail plant diseases is causing negative effects on the agro-ecosystem. The high scale prevalence of diseases in crops affects the production quantity and quality. Solving the problem of early identification/diagnosis of diseases by exploiting a quick and consistent reliable method will benefit the farmers. In this context, our research work focuses on classification and identification of tomato leaf diseases using convolutional neural network (CNN) techniques. We consider four CNN architectures, namely, VGG-16, VGG-19, ResNet, and Inception V3, and use feature extraction and parameter-tuning to identify and classify tomato leaf diseases. We test the underlying models on two datasets, a laboratory-based dataset and self-collected data from the field. We observe that all architectures perform better on the laboratory-based dataset than on field-based data, with performance on various metrics showing variance in the range 10%–15%. Inception V3 is identified as the best performing algorithm on both datasets.

Background In recent years, ecofriendly compounds such as chitosan has been used to alleviate the destructive effects of salt stress. Chitosan is a natural biodegradable compound with no toxicity in nature and act as a stress tolerance inductor involved in physiological processes and prevent water loss through transpiration. Tomato cv. Rio Grande grown in pots was subjected with salinity stress in the form of 4 levels (0, 50, 100 and 150 mM) whose effect was mediated by treating it with different concentration of chitosan (0, 50, 100 and 150 mg L−1). Results The data revealed that various application of salinity had a negative effect on almost all the studied parameters. Tomato plants treated with distilled water having no salinity (control) recorded maximum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), fruit juice pH, yield plant−1 (kg) and minimum total soluble solids (Brix°). Whereas, minimum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), fruit juice pH, yield plant−1 (kg) and maximum total soluble solids (Brix°) were found in plants treated with salinity level of 150 mM. Chitosan concentration of 150 mg L−1 significantly mediated the effect of salinity stress and recorded maximum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), total soluble solids (Brix°) and yield plant−1 (kg) with minimum fruit juice pH. Conclusion It is concluded that foliar application of chitosan at the rate of 150 mg L−1 and salinity stress 150 mM could have positive impact on performance of tomato.

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The pre-harvest treatment of gibbrellic acid (GA 3) as foliar spray was applied to chrysanthemum cultivars in order to investigate its impact on flower quality, persistency on plant and vase life. The Randomized Complete Block Design (RCBD) with two factors factorial arrangement was used with foliar application of GA 3 (0, 50, 100, 150mgL-1) sprayed on chrysanthemum cultivars (Rebbonet, Revert, Resomme and Magdalena) at button stage of flower buds. The foliar application of GA 3 significantly influenced most of the growth parameters and enhanced the quality of flowers in chrysanthemum cultivars. However, the chrysanthemum plants when treated with gibbrellic acid (GA 3) at the rate of 100mgL-1 resulted in maximum bud size (2.29cm), flower size (13.91cm), flower persistency on plant (51.14days), fresh flower weight (14.66g), dry flower weight (6.03g) and vase life (37.15days). The cultivar Rebbonet showed the highest bud size (2.28cm), flower size (12.20cm), number of days to flower persistency (47.00), fresh flower weight (12.45g), dry flower weight (5.08g), vase life (31.00days) and the least percent flower petal fading (9.69%). The foliar application of gibbrellic acid at the rate of 100 mg L-1 significantly influenced the growth and quality flower production of chrysanthemum cultivar Rebbonet. It was concluded that the cultivar Rebonnet could be sprayed with foliar application of gibbrellic acid (GA 3) at the rate of 100 mg L-1 to obtain quality flowers under the agro climatic condition of Peshawar,