According to Philippine Atmospheric Geophysical and Astronomical Services Administration (Pagasa), El Niño, a weather phenomenon characterized by dry spells, may peak in February. Sunstar Davao (28 december 2009) reported that Davao City and the provinces of Davao Region have been categorized as moderately vulnerable to the El Niño phenomenon alongside with the provinces of Abra, Apayao, Benguet, Ifugao, Mt Province, Isabela, Nueva Vizcaya, Quirino, Batangas, Laguna, Quezon, Romblon, Sorsogon, Aklan, Antique, Bohol, Samar, Zamboanga Norte, Zamboanga Sibugay, Zamboanga Sur, and Bukidnon. The Center for Initiative and Research on Climate Adaptation (Circa) explained that the El Niño/Southern Oscillation (Eenso) is a recurrent ocean-warming and atmospheric disturbance resulting in deficient rainfall or prolonged drought. This phenomenon is expected to adversely affect crop production.
Drought is a major limiting factor in farming. Limited moisture suppresses the growth of crops, weakens the resistance to pests and diseases, affects nutrient utilization and usually decreases the quality and quantity of yield. Drought can cause damage to cell membranes. Not all plants develop antioxidant defense systems to cope with drought such that application of natural plant supplements that enhances resistance to drought maybe necessary during drought. Cytokinins, a class of phytohormones, function as antioxidants and have been shown to improve drought resistance and exhibit anti-senescence properties Musgrave,1994. Thimann (1987) noted that cytokinins delay the senescence process probably by maintaining the integrity of the tonoplast membrane. Tonoplast membrane is the cytoplasmic membrane surrounding the vacuole, separating the vacuolar contents from the cytoplasm in a cell. As a membrane, it is mainly involved in regulating the movements of ions around the cell, and isolating materials that might be harmful or a threat to the cell (www.biology-online.org/dictionary)