Publisher's Synopsis
Numerous plant disease problems can arise in greenhouse situations. These diseases can cause extensive damage of allowed to develop unchecked. Since plant disease is strongly affected by temperature and humidity, the best way to combat disease is to manipulate the greenhouse environment. Unlike the weather outdoors, we can control the greenhouse environment. High humidity levels encourage the development of many plant diseases. The relative humidity is usually 25%-70% during the day in greenhouses and generally no problem. However, humidity levels are generally 90-100% during the night. During periods of rainy weather in winter, the relative humidity may stay near 100% for a number of days and nights. Maintain adequate plant spacing. When plants are crowded together, disease development is encouraged by the high humidity in the canopy. Plants hung overhead reduce normal water evaporation and contribute to high humidity in the crop canopy. Maintain air circulation during periods of high humidity. The risk of plant diseases is reduced when the foliage and flowers are kept dry. Most disease organisms need water on the plant surface for normal growth. Additionally, splashing water is the primary method of spreading disease from plant to plant. Keep the greenhouse clean and free of plant debris and outside soil. Remove dead leaves, flowers, plant refuse and weeds from the greenhouse. Debris should be gathered regularly and discarded as soon as possible after collecting. Immediate removal is important because certain fungal pathogens can develop and produce spores on the plant debris. This book covers all the aspects of designing, operation and economics of Greenhouses. Care has been taken to include applied aspects and present scenario of different practices necessary for this subject. -
