Bronchogenic Carcinoma: Given the patient's 25-year history of working in a pesticide manufacturing plant, which is a known risk factor for lung cancer due to exposure to carcinogenic chemicals, along with symptoms of hemoptysis, nonproductive cough, and shortness of breath, this diagnosis is highly plausible. The presence of clubbing on physical examination further supports this diagnosis, as it is a common finding in lung cancer.

Chronic Obstructive Pulmonary Disease (COPD): Although COPD typically presents with a productive cough, the long history of working in an environment with potential respiratory irritants could contribute to COPD, which might explain some of the symptoms.
Pneumoconiosis: Given the occupational history, pneumoconiosis (a category of lung diseases that result from the inhalation of dust particles) is a possibility, especially if the patient was exposed to specific types of dust over his 25-year career.
Tuberculosis: Although the patient does not have fever or chills, tuberculosis (TB) can present with hemoptysis and chronic cough. The absence of systemic symptoms does not rule out TB, especially in endemic areas or in individuals with certain risk factors.

Pulmonary Embolism: This is a critical diagnosis to consider in any patient presenting with acute onset of shortness of breath and could be a cause of hemoptysis, although it is less likely given the chronic nature of the symptoms.
Infectious Causes (e.g., Pneumonia, Bronchiectasis): Despite the lack of fever, certain infections could still be present, especially if the patient is immunocompromised or has an underlying condition that predisposes him to specific infections.
Goodpasture Syndrome: An autoimmune disease that can cause hemoptysis and renal failure. It's less common but critical to diagnose early due to its potential for severe outcomes.

Lymphangitic Carcinomatosis: A rare condition where cancer spreads to the lymphatic vessels of the lungs, causing respiratory symptoms.
Idiopathic Pulmonary Hemosiderosis: A rare condition characterized by recurrent episodes of diffuse alveolar hemorrhage, leading to hemoptysis and respiratory distress.
Eosinophilic Pneumonia: A group of diseases characterized by an accumulation of eosinophils in the lungs, which can cause a variety of respiratory symptoms, including cough and shortness of breath.