Influence of Naphthalene Acetic Acid (PGR) on the Growth, Yield and Susceptibility to Specific Chili Paper Disease in Different Chilies Cultivars (Capsicum annuum) in the Upland of Baluchistan

Abstract

Capsicum annuum, commonly known as chili pepper, is a significant spice crop worldwide, and its yield and fruit quality are important factors affecting economic returns for growers. However, these can be impacted by various abiotic and biotic stresses, including environmental conditions, nutrient deficiencies, pests, and diseases. Utilizing growth regulators for plants, such NAA, has emerged as a viable strategy to enhance growth, improve yield, and mitigate stress effects in chili production. To ascertain the impact of the plant growth regulator (NAA) on the development and yield of chilies, a field experiment was carried out. Plant pathogens pose a significant threat to agricultural productivity worldwide. The main challenge in this scenario is that the plant pathogens are dynamic organisms that adapt to changing environmental conditions and agricultural methods. Examples of this kind of evolution include the appearance and spread of novel diseases or more aggressive pathogens that are resistant to fungicides. Using three replications and seven treatments, randomized complete block design (RCBD) was used to perform the experiment. Control (applying no naphthalene acetic acid), 25 ppm, 50 ppm, 75 ppm, 100 ppm, 125 ppm, and 150 ppm applications of naphthalene acetic acid. The result shows that chili crop treated with application of NAA @ 125 ppm exhibited significantly maximum resulted with 80.95 cm plant height, 15.13 quantity of branches plant-1, 84.24 days to flowering, 100.02 days to fruit set, 8.65 cm fruit length, 42.89 g fruit weight, 36.72 quantity of fruits plant-1 and 0.43 kg yield plant-1. In contrast, chili treated under control exhibited the lowest performance, 53.98 cm plant height, 10.49 quantity of branches plant-1, 82.46 days to flowering, 90.77 days to fruit set, 5.66 cm fruit length, 22.54 g fruit weight, 20.39 quantity of fruits plant-1 and 0.02 kg yield plant-1. Among the chili variety, Hot chilies yielded the best results, with 69.31 cm plant height, 13.15 quantity of branches plant-1, 83.52 days to flowering, 96.05 days to fruit set, 7.39 cm fruit length, 34.07 g fruit weight, 29.71 quantity of fruits plant-1 and 0.25 kg yield plant-1. On the other hand, the variety SKY Cross showed the lowest performance, with 65.41 cm plant height, 12.49 quantity of branches plant-1, 83.24 days to flowering, 94.73 days to fruit set, 6.96 cm fruit length, 31.17 g fruit weight, 27.36 quantity of fruits plant-1 and 0.19 kg yield plant-1. After going through the findings of the present research, it was concluded that the application of NAA at 125 ppm showed superior results in terms of plant height, quantity of branches, days to flowering and fruit set, fruit length, fruit weight, quantity of fruits per plant, and overall yield per plant compared to other concentrations of NAA and the control group. The research findings show that that NAA at 125 ppm can be an effective growth regulator for chili crops, leading to improved growth and increased yields.